References: The Thin Guide to Fat

70 years of confusing nutrition advice, with dietary-fat guidelines introduced without strong trial evidence.

• Harcombe, Z. et al. (2015) 'Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis', Open Heart, 2(1), e000196. doi:10.1136/openhrt-2014-000196

More people are reaching target weights than in past decades.

• NHS Digital (2020) Health Survey for England 2019: Overweight and obesity in adults and children. Available at: https://digital.nhs.uk/data-and-information/publications/statistical/health-survey-for-england/2019

Modern diets leave us "over-fed but nutritionally starving".

• Hall, K.D. et al. (2019) 'Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake', Cell Metabolism, 30(1), pp. 67–77.e3. doi:10.1016/j.cmet.2019.05.008

Simply restricting calories is not effective; calories from protein, fat and carbohydrate act differently.

• Hall, K.D. and Guo, J. (2017) 'Obesity energetics: body weight regulation and the effects of diet composition', Gastroenterology, 152(7), pp. 1718–1727.e3. doi:10.1053/j.gastro.2017.01.052
• Gardner, C.D. et al. (2018) 'Effect of low-fat vs low-carbohydrate diet on 12-month weight loss in overweight adults and the association with genotype pattern or insulin secretion: the DIETFITS randomized clinical trial', JAMA, 319(7), pp. 667–679. doi:10.1001/jama.2018.0245
• Ludwig, D.S. and Ebbeling, C.B. (2018) 'The carbohydrate-insulin model of obesity: beyond "calories in, calories out"', JAMA Internal Medicine, 178(8), pp. 1098–1103. doi:10.1001/jamainternmed.2018.2933

Focusing on blood insulin, not just blood glucose, helps people reach weight and health goals.

• Crofts, C. et al. (2016) 'Identifying hyperinsulinaemia in the absence of impaired glucose tolerance: an examination of the Kraft database', Diabetes Research and Clinical Practice, 118, pp. 50–57. doi:10.1016/j.diabres.2016.06.007

"Eat little and often" is counterproductive; eating less often helps.

• Schoenfeld, B.J., Aragon, A.A. and Krieger, J.W. (2015) 'Effects of meal frequency on weight loss and body composition: a meta-analysis', Nutrition Reviews, 73(2), pp. 69–82. doi:10.1093/nutrit/nuu017
• Cameron, J.D., Cyr, M.J. and Doucet, É. (2010) 'Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet', British Journal of Nutrition, 103(8), pp. 1098–1101. doi:10.1017/S0007114509992984

Seed oils have led to weight gain and sickness.

• Hooper, L. et al. (2018) 'Omega-6 fats for the primary and secondary prevention of cardiovascular disease', Cochrane Database of Systematic Reviews, 11, CD011094. doi:10.1002/14651858.CD011094.pub4
• Marklund, M. et al. (2019) 'Biomarkers of dietary omega-6 fatty acids and incident cardiovascular disease and mortality', Circulation, 139(21), pp. 2422–2436. doi:10.1161/CIRCULATIONAHA.118.038908

Running mainly on glucose speeds ageing, and fuelling the brain mainly on glucose contributes to dementia.

• Crane, P.K. et al. (2013) 'Glucose levels and risk of dementia', New England Journal of Medicine, 369(6), pp. 540–548. doi:10.1056/NEJMoa1215740
• Cunnane, S.C. et al. (2020) 'Brain energy rescue: an emerging therapeutic concept for neurodegenerative disorders of ageing', Nature Reviews Drug Discovery, 19(9), pp. 609–633. doi:10.1038/s41573-020-0072-x

Fasting gives access to "a limitless supply" of stored energy.

• Cahill, G.F. Jr (2006) 'Fuel metabolism in starvation', Annual Review of Nutrition, 26, pp. 1–22. doi:10.1146/annurev.nutr.26.061505.111258

"Eat less, move more" (pounding treadmills) actually prevents weight loss.

• Pontzer, H. et al. (2016) 'Constrained total energy expenditure and metabolic adaptation to physical activity in adult humans', Current Biology, 26(3), pp. 410–417. doi:10.1016/j.cub.2015.12.046

Red meat can decrease frailty in old age and improve midlife performance.

• Bauer, J. et al. (2013) 'Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group', Journal of the American Medical Directors Association, 14(8), pp. 542–559. doi:10.1016/j.jamda.2013.05.021
• Johnston, B.C. et al. (2019) 'Unprocessed red meat and processed meat consumption: dietary guideline recommendations from the Nutritional Recommendations (NutriRECS) Consortium', Annals of Internal Medicine, 171(10), pp. 756–764. doi:10.7326/M19-1621

Over-emphasis on vegetables and plant-based diets has become problematic for health.

• Aune, D. et al. (2017) 'Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality—a systematic review and dose-response meta-analysis of prospective studies', International Journal of Epidemiology, 46(3), pp. 1029–1056. doi:10.1093/ije/dyw319

Dietary guidelines since the 1970s have shaped our weight and health.

• Harcombe, Z. et al. (2015) 'Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis', Open Heart, 2(1), e000196. doi:10.1136/openhrt-2014-000196

The body can run on two fuels, sugar or fat, like a hybrid car.

• Goodpaster, B.H. and Sparks, L.M. (2017) 'Metabolic flexibility in health and disease', Cell Metabolism, 25(5), pp. 1027–1036. doi:10.1016/j.cmet.2017.04.015

Sugar as a fuel ages us faster, leads to inflammatory diseases and "drags us toward dementia"; fat as a fuel keeps us trim and ensures mental clarity into old age.

• Uribarri, J. et al. (2010) 'Advanced glycation end products in foods and a practical guide to their reduction in the diet', Journal of the American Dietetic Association, 110(6), pp. 911–916.e12. doi:10.1016/j.jada.2010.03.018
• Crane, P.K. et al. (2013) 'Glucose levels and risk of dementia', New England Journal of Medicine, 369(6), pp. 540–548. doi:10.1056/NEJMoa1215740
• Seidelmann, S.B. et al. (2018) 'Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis', Lancet Public Health, 3(9), pp. e419–e428. doi:10.1016/S2468-2667(18)30135-X

The American Heart Association now admits that saturated fat is not harmful to the heart.

• Sacks, F.M. et al. (2017) 'Dietary fats and cardiovascular disease: a presidential advisory from the American Heart Association', Circulation, 136(3), pp. e1–e23. doi:10.1161/CIR.0000000000000510
• Hooper, L. et al. (2020) 'Reduction in saturated fat intake for cardiovascular disease', Cochrane Database of Systematic Reviews, 8, CD011737. doi:10.1002/14651858.CD011737.pub3

Recommended polyunsaturated oils are not as healthy as we were told.

• Ramsden, C.E. et al. (2013) 'Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis', BMJ, 346, e8707. doi:10.1136/bmj.e8707
• Ramsden, C.E. et al. (2016) 'Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968–73)', BMJ, 353, i1246. doi:10.1136/bmj.i1246

The mantras "heart-healthy whole grains", "high fibre" and "low fat" are being challenged.

• Aune, D. et al. (2016) 'Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies', BMJ, 353, i2716. doi:10.1136/bmj.i2716
• Reynolds, A. et al. (2019) 'Carbohydrate quality and human health: a series of systematic reviews and meta-analyses', Lancet, 393(10170), pp. 434–445. doi:10.1016/S0140-6736(18)31809-9

Starchy "healthy" carbohydrates (potatoes, cereal, brown bread, pasta) break down to glucose, and fruit provides fructose.

• Atkinson, F.S., Foster-Powell, K. and Brand-Miller, J.C. (2008) 'International tables of glycemic index and glycemic load values: 2008', Diabetes Care, 31(12), pp. 2281–2283. doi:10.2337/dc08-1239

To lose weight, carbohydrate/sugar should be limited to 20–50 g per day.

• Feinman, R.D. et al. (2015) 'Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base', Nutrition, 31(1), pp. 1–13. doi:10.1016/j.nut.2014.06.011

Hidden-sugar table (e.g. 150 g boiled potato ≈ 9 tsp sugar).

• Unwin, D., Haslam, D. and Livesey, G. (2016) 'It is the glycaemic response to, not the carbohydrate content of food that matters in diabetes and obesity: the glycaemic index revisited', Journal of Insulin Resistance (now Journal of Metabolic Health), 1(1). doi:10.4102/jir.v1i1.8
• Atkinson, F.S., Foster-Powell, K. and Brand-Miller, J.C. (2008) 'International tables of glycemic index and glycemic load values: 2008', Diabetes Care, 31(12), pp. 2281–2283. doi:10.2337/dc08-1239

Manufacturers removed fat and added sugar to keep flavour.

• Nguyen, P.K., Lin, S. and Heidenreich, P. (2016) 'A systematic comparison of sugar content in low-fat vs regular versions of food', Nutrition & Diabetes, 6(1), e193. doi:10.1038/nutd.2015.43

Insulin moves glucose from carbohydrate into cells.

• Petersen, M.C. and Shulman, G.I. (2018) 'Mechanisms of insulin action and insulin resistance', Physiological Reviews, 98(4), pp. 2133–2223. doi:10.1152/physrev.00063.2017

While insulin is present we cannot burn body fat, and eaten fat is stored.

• Petersen, M.C. and Shulman, G.I. (2018) 'Mechanisms of insulin action and insulin resistance', Physiological Reviews, 98(4), pp. 2133–2223. doi:10.1152/physrev.00063.2017

Sugars, grains and carbohydrates are the biggest triggers of insulin.

• Holt, S.H., Miller, J.C. and Petocz, P. (1997) 'An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods', American Journal of Clinical Nutrition, 66(5), pp. 1264–1276. doi:10.1093/ajcn/66.5.1264

Seed oils enhance fat storage and cause further over-production of insulin.

• Imamura, F. et al. (2016) 'Effects of saturated fat, polyunsaturated fat, monounsaturated fat, and carbohydrate on glucose-insulin homeostasis: a systematic review and meta-analysis of randomised controlled feeding trials', PLoS Medicine, 13(7), e1002087. doi:10.1371/journal.pmed.1002087

100 kcal of cheese omelette is less fattening than 100 kcal of buttered toast. Fat plus carbohydrate stores excess energy, but fat plus protein does not.

• Bray, G.A. et al. (2012) 'Effect of dietary protein content on weight gain, energy expenditure, and body composition during overeating: a randomized controlled trial', JAMA, 307(1), pp. 47–55. doi:10.1001/jama.2011.1918
• Hall, K.D. et al. (2016) 'Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men', American Journal of Clinical Nutrition, 104(2), pp. 324–333. doi:10.3945/ajcn.116.133561

Animal foods contain protein and fat but (almost) no carbohydrate; mammalian milk combines fat and sugar (lactose).

• Ballard, O. and Morrow, A.L. (2013) 'Human milk composition: nutrients and bioactive factors', Pediatric Clinics of North America, 60(1), pp. 49–74. doi:10.1016/j.pcl.2012.10.002

Nothing lays down fat faster than sugar and fat together.

• DiFeliceantonio, A.G. et al. (2018) 'Supra-additive effects of combining fat and carbohydrate on food reward', Cell Metabolism, 28(1), pp. 33–44.e3. doi:10.1016/j.cmet.2018.05.018

When we are young and healthy, a small amount of insulin clears glucose quickly.

• Karakelides, H. et al. (2010) 'Age, obesity, and sex effects on insulin sensitivity and skeletal muscle mitochondrial function', Diabetes, 59(1), pp. 89–97. doi:10.2337/db09-0591

Raised insulin stores excess energy as fat and blocks fat burning.

• Petersen, M.C. and Shulman, G.I. (2018) 'Mechanisms of insulin action and insulin resistance', Physiological Reviews, 98(4), pp. 2133–2223. doi:10.1152/physrev.00063.2017

Years of overeating make the body less sensitive to insulin, so the pancreas makes more and insulin stays raised.

• Shanik, M.H. et al. (2008) 'Insulin resistance and hyperinsulinemia: is hyperinsulinemia the cart or the horse?', Diabetes Care, 31(Suppl 2), pp. S262–S268. doi:10.2337/dc08-s264
• Corkey, B.E. (2012) 'Banting Lecture 2011: Hyperinsulinemia: cause or consequence?', Diabetes, 61(1), pp. 4–13. doi:10.2337/db11-1483

Insulin resistance increases with age and "overuse", which raises insulin output.

• Karakelides, H. et al. (2010) 'Age, obesity, and sex effects on insulin sensitivity and skeletal muscle mitochondrial function', Diabetes, 59(1), pp. 89–97. doi:10.2337/db09-0591

People who understand this are reversing type 2 diabetes.

• Hallberg, S.J. et al. (2018) 'Effectiveness and safety of a novel care model for the management of type 2 diabetes at 1 year: an open-label, non-randomized, controlled study', Diabetes Therapy, 9(2), pp. 583–612. doi:10.1007/s13300-018-0373-9
• Lean, M.E. et al. (2018) 'Primary care-led weight management for remission of type 2 diabetes (DiRECT): an open-label, cluster-randomised trial', Lancet, 391(10120), pp. 541–551. doi:10.1016/S0140-6736(17)33102-1

Too much insulin is "the driver" of inflammation and drives type 2 diabetes, high blood pressure, heart disease, migraine, infertility, arthritis, Crohn's/colitis, psoriasis, asthma, dementia and cancers.

• Reaven, G.M. (1988) 'Banting lecture 1988. Role of insulin resistance in human disease', Diabetes, 37(12), pp. 1595–1607. doi:10.2337/diab.37.12.1595
• Rainero, I. et al. (2005) 'Insulin sensitivity is impaired in patients with migraine', Cephalalgia, 25(8), pp. 593–597. doi:10.1111/j.1468-2982.2005.00928.x
• Diamanti-Kandarakis, E. and Dunaif, A. (2012) 'Insulin resistance and the polycystic ovary syndrome revisited: an update on mechanisms and implications', Endocrine Reviews, 33(6), pp. 981–1030. doi:10.1210/er.2011-1034
• de la Monte, S.M. and Wands, J.R. (2008) 'Alzheimer's disease is type 3 diabetes—evidence reviewed', Journal of Diabetes Science and Technology, 2(6), pp. 1101–1113. doi:10.1177/193229680800200619

Diet sodas trigger insulin.

• Nichol, A.D., Holle, M.J. and An, R. (2018) 'Glycemic impact of non-nutritive sweeteners: a systematic review and meta-analysis of randomized controlled trials', European Journal of Clinical Nutrition, 72(6), pp. 796–804. doi:10.1038/s41430-018-0170-6

Poor sleep raises insulin / insulin resistance, and 7–8 hours of sleep are advisable.

• Spiegel, K., Leproult, R. and Van Cauter, E. (1999) 'Impact of sleep debt on metabolic and endocrine function', Lancet, 354(9188), pp. 1435–1439. doi:10.1016/S0140-6736(99)01376-8
• Donga, E. et al. (2010) 'A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects', Journal of Clinical Endocrinology & Metabolism, 95(6), pp. 2963–2968. doi:10.1210/jc.2009-2430
• Watson, N.F. et al. (2015) 'Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society', Sleep, 38(6), pp. 843–844. doi:10.5665/sleep.4716

Alcohol leads to poor food choices afterwards.

• Yeomans, M.R. (2010) 'Alcohol, appetite and energy balance: is alcohol intake a risk factor for obesity?', Physiology & Behavior, 100(1), pp. 82–89. doi:10.1016/j.physbeh.2010.01.012

Carbohydrates spike insulin significantly, proteins insignificantly, and saturated fats not at all.

• Holt, S.H., Miller, J.C. and Petocz, P. (1997) 'An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods', American Journal of Clinical Nutrition, 66(5), pp. 1264–1276. doi:10.1093/ajcn/66.5.1264

Protein and fat give satiety, fewer cravings and less overeating.

• Leidy, H.J. et al. (2015) 'The role of protein in weight loss and maintenance', American Journal of Clinical Nutrition, 101(6), pp. 1320S–1329S. doi:10.3945/ajcn.114.084038
• Gibson, A.A. et al. (2015) 'Do ketogenic diets really suppress appetite? A systematic review and meta-analysis', Obesity Reviews, 16(1), pp. 64–76. doi:10.1111/obr.12230

Snacking on carbohydrate causes blood-sugar dips that bring hunger back, whereas fat and protein snacks avoid this.

• Wyatt, P. et al. (2021) 'Postprandial glycaemic dips predict appetite and energy intake in healthy individuals', Nature Metabolism, 3(4), pp. 523–529. doi:10.1038/s42255-021-00383-x

We cannot burn fat until blood sugar has been used and insulin cleared (about 4 h), or until liver glycogen is used (about 12 h).

• Rothman, D.L. et al. (1991) 'Quantitation of hepatic glycogenolysis and gluconeogenesis in fasting humans with 13C NMR', Science, 254(5031), pp. 573–576. doi:10.1126/science.1948033
• Cahill, G.F. Jr (2006) 'Fuel metabolism in starvation', Annual Review of Nutrition, 26, pp. 1–22. doi:10.1146/annurev.nutr.26.061505.111258

Eating protein and carbohydrate together produces a bigger insulin response than either alone.

• Nuttall, F.Q. et al. (1984) 'Effect of protein ingestion on the glucose and insulin response to a standardized oral glucose load', Diabetes Care, 7(5), pp. 465–470. doi:10.2337/diacare.7.5.465

If you understand insulin you can tap fat stores for "limitless energy"; calorie restriction without lowering insulin blocks access to fat.

• Hall, K.D. et al. (2015) 'Calorie for calorie, dietary fat restriction results in more body fat loss than carbohydrate restriction in people with obesity', Cell Metabolism, 22(3), pp. 427–436. doi:10.1016/j.cmet.2015.07.021

Severe calorie restriction (800 kcal) slows metabolism (adaptive thermogenesis) and encourages regain.

• Rosenbaum, M. and Leibel, R.L. (2010) 'Adaptive thermogenesis in humans', International Journal of Obesity, 34(Suppl 1), pp. S47–S55. doi:10.1038/ijo.2010.184
• Fothergill, E. et al. (2016) 'Persistent metabolic adaptation 6 years after "The Biggest Loser" competition', Obesity, 24(8), pp. 1612–1619. doi:10.1002/oby.21538

800-kcal diets typically fail because of high insulin.

• Lean, M.E. et al. (2018) 'Primary care-led weight management for remission of type 2 diabetes (DiRECT): an open-label, cluster-randomised trial', Lancet, 391(10120), pp. 541–551. doi:10.1016/S0140-6736(17)33102-1

Dr Joseph Kraft developed insulin-response testing in the mid-20th century, and it detects "diabetes in situ" years before glucose tests do.

• Kraft, J.R. (1975) 'Detection of diabetes mellitus in situ (occult diabetes)', Laboratory Medicine, 6(2), pp. 10–22. doi:10.1093/labmed/6.2.10
• Crofts, C. et al. (2016) 'Identifying hyperinsulinaemia in the absence of impaired glucose tolerance: an examination of the Kraft database', Diabetes Research and Clinical Practice, 118, pp. 50–57. doi:10.1016/j.diabres.2016.06.007

Rising insulin keeps glucose normal for years, so standard tests miss the problem.

• Crofts, C. et al. (2016) 'Identifying hyperinsulinaemia in the absence of impaired glucose tolerance: an examination of the Kraft database', Diabetes Research and Clinical Practice, 118, pp. 50–57. doi:10.1016/j.diabres.2016.06.007

The "old guard" believe type 2 diabetes is a problem of too little insulin; the "new understanding" is that it is too much insulin.

• DeFronzo, R.A. (2009) 'From the triumvirate to the ominous octet: a new paradigm for the treatment of type 2 diabetes mellitus', Diabetes, 58(4), pp. 773–795. doi:10.2337/db09-9028

People with type 2 diabetes are achieving remission and coming off medication through diet.

• Unwin, D. et al. (2020) 'Insights from a general practice service evaluation supporting a lower carbohydrate diet in patients with type 2 diabetes mellitus and prediabetes: a secondary analysis of routine clinic data including HbA1c, weight and prescribing over 6 years', BMJ Nutrition, Prevention & Health, 3(2), pp. 285–294. doi:10.1136/bmjnph-2020-000072

Dr David Unwin won NHS Innovator of the Year 2016.

• McCoid, S. (2016) 'Southport GP named NHS innovator of the year at London ceremony', Southport Visiter, 11 March. Available at: https://www.southportvisiter.co.uk/news/southport-west-lancs/southport-gp-named-nhs-innovator-11020379

His fastest type 2 diabetes remission was 38 days.

• Diet Doctor (2019) Diet Doctor Podcast #33 with Dr David Unwin [transcript]. Available at: https://www.dietdoctor.com/wp-content/uploads/2019/10/VIDEO-Diet-Doctor-Podcast-with-Dr-David-Unwin-Episode-33-1.pdf

His practice saved £57,000 on blood-pressure and diabetes drugs in one year.

• Hawkes, N. (2016) 'Diabetes team finalists', BMJ, 353, i2183. doi:10.1136/bmj.i2183
• Unwin, D. et al. (2020) 'Insights from a general practice service evaluation supporting a lower carbohydrate diet in patients with type 2 diabetes mellitus and prediabetes: a secondary analysis of routine clinic data including HbA1c, weight and prescribing over 6 years', BMJ Nutrition, Prevention & Health, 3(2), pp. 285–294. doi:10.1136/bmjnph-2020-000072

Fibre is not essential.

• Institute of Medicine (2005) Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academies Press. doi:10.17226/10490
• Reynolds, A. et al. (2019) 'Carbohydrate quality and human health: a series of systematic reviews and meta-analyses', Lancet, 393(10170), pp. 434–445. doi:10.1016/S0140-6736(18)31809-9

The traditional Inuit diet came from the sea, as nothing grows above 4 cm; nomadic tribes live on dairy and meat.

• Kuhnlein, H.V. et al. (2004) 'Arctic indigenous peoples experience the nutrition transition with changing dietary patterns and obesity', Journal of Nutrition, 134(6), pp. 1447–1453. doi:10.1093/jn/134.6.1447
• Mann, G.V. et al. (1964) 'Cardiovascular disease in the Masai', Journal of Atherosclerosis Research, 4(4), pp. 289–312. doi:10.1016/S0368-1319(64)80041-7

A diverse gut flora can be kept without fibre on an animal-based diet, and gut production of B vitamins/folate increases on such a diet.

• David, L.A. et al. (2014) 'Diet rapidly and reproducibly alters the human gut microbiome', Nature, 505(7484), pp. 559–563. doi:10.1038/nature12820
• LeBlanc, J.G. et al. (2013) 'Bacteria as vitamin suppliers to their host: a gut microbiota perspective', Current Opinion in Biotechnology, 24(2), pp. 160–168. doi:10.1016/j.copbio.2012.08.005

Fibre is not absorbed and provides no calories.

• FAO (2003) Food energy – methods of analysis and conversion factors. FAO Food and Nutrition Paper 77. Rome: FAO. Available at: https://www.fao.org/4/Y5022E/y5022e04.htm

Vegans are often "unhealthily thin".

• Spencer, E.A. et al. (2003) 'Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans', International Journal of Obesity, 27(6), pp. 728–734. doi:10.1038/sj.ijo.0802300
• Tong, T.Y.N. et al. (2020) 'Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study', BMC Medicine, 18, 353. doi:10.1186/s12916-020-01815-3

A high-energy, fat-rich diet led to bigger brains and shorter guts than other primates.

• Aiello, L.C. and Wheeler, P. (1995) 'The expensive-tissue hypothesis: the brain and the digestive system in human and primate evolution', Current Anthropology, 36(2), pp. 199–221. doi:10.1086/204350

A plant-based diet cannot provide the nutrients we need to be healthy.

• Melina, V., Craig, W. and Levin, S. (2016) 'Position of the Academy of Nutrition and Dietetics: vegetarian diets', Journal of the Academy of Nutrition and Dietetics, 116(12), pp. 1970–1980. doi:10.1016/j.jand.2016.09.025

Complete protein and minerals are more concentrated and bioavailable in animal foods.

• Gorissen, S.H.M. et al. (2018) 'Protein content and amino acid composition of commercially available plant-based protein isolates', Amino Acids, 50(12), pp. 1685–1695. doi:10.1007/s00726-018-2640-5
• Hurrell, R. and Egli, I. (2010) 'Iron bioavailability and dietary reference values', American Journal of Clinical Nutrition, 91(5), pp. 1461S–1467S. doi:10.3945/ajcn.2010.28674F

More fibre is blamed for rising intestinal problems.

• Ho, K.S. et al. (2012) 'Stopping or reducing dietary fiber intake reduces constipation and its associated symptoms', World Journal of Gastroenterology, 18(33), pp. 4593–4596. doi:10.3748/wjg.v18.i33.4593

Plant lectins may be triggering autoimmune diseases.

• Vojdani, A. (2015) 'Lectins, agglutinins, and their roles in autoimmune reactivities', Alternative Therapies in Health and Medicine, 21(Suppl 1), pp. 46–51. Available at: https://pubmed.ncbi.nlm.nih.gov/25599185/

Anecdotal evidence shows improvement in intestinal disorders on meat-only elimination diets.

• Lennerz, B.S. et al. (2021) 'Behavioral characteristics and self-reported health status among 2029 adults consuming a "carnivore diet"', Current Developments in Nutrition, 5(12), nzab133. doi:10.1093/cdn/nzab133

Pasture-raised animal fat is rich in the fat-soluble vitamins A, D, E and K.

• Daley, C.A. et al. (2010) 'A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef', Nutrition Journal, 9, 10. doi:10.1186/1475-2891-9-10

The AHA admits saturated fat is not harmful to heart health.

• Sacks, F.M. et al. (2017) 'Dietary fats and cardiovascular disease: a presidential advisory from the American Heart Association', Circulation, 136(3), pp. e1–e23. doi:10.1161/CIR.0000000000000510

Saturated fat is fundamental to brain-cell structure and "essential in higher quantities".

• Bazinet, R.P. and Layé, S. (2014) 'Polyunsaturated fatty acids and their metabolites in brain function and disease', Nature Reviews Neuroscience, 15(12), pp. 771–785. doi:10.1038/nrn3820

Grains are lower in calories than fat.

• FAO (2003) Food energy – methods of analysis and conversion factors. FAO Food and Nutrition Paper 77. Rome: FAO. Available at: https://www.fao.org/4/Y5022E/y5022e04.htm

Saturated fat is stable when heated, while seed oils oxidise easily with light and heat.

• Katragadda, H.R. et al. (2010) 'Emissions of volatile aldehydes from heated cooking oils', Food Chemistry, 120(1), pp. 59–65. doi:10.1016/j.foodchem.2009.09.070

LDL is an "efficient energy distribution system" carrying fat energy to cells.

• Brown, M.S. and Goldstein, J.L. (1986) 'A receptor-mediated pathway for cholesterol homeostasis', Science, 232(4746), pp. 34–47. doi:10.1126/science.3513311

High-sugar diets damage (glycate or oxidise) LDL, and insulin resistance makes damaged LDL linger.

• Younis, N. et al. (2009) 'Glycation of LDL in non-diabetic people: small dense LDL is preferentially glycated both in vivo and in vitro', Atherosclerosis, 202(1), pp. 162–168. doi:10.1016/j.atherosclerosis.2008.04.036
• Austin, M.A. et al. (1988) 'Low-density lipoprotein subclass patterns and risk of myocardial infarction', JAMA, 260(13), pp. 1917–1921. doi:10.1001/jama.1988.03410130125037

LDL protects against infection.

• Netea, M.G. et al. (1996) 'Low-density lipoprotein receptor-deficient mice are protected against lethal endotoxemia and severe gram-negative infections', Journal of Clinical Investigation, 97(6), pp. 1366–1372. doi:10.1172/JCI118556
• Ravnskov, U. (2003) 'High cholesterol may protect against infections and atherosclerosis', QJM, 96(12), pp. 927–934. doi:10.1093/qjmed/hcg150

We evolved eating large amounts of saturated fat as our energy source.

• Ben-Dor, M., Sirtoli, R. and Barkai, R. (2021) 'The evolution of the human trophic level during the Pleistocene', American Journal of Physical Anthropology, 175(Suppl 72), pp. 27–56. doi:10.1002/ajpa.24247

Ketones are the preferred energy source for the brain and heart.

• Cahill, G.F. Jr (2006) 'Fuel metabolism in starvation', Annual Review of Nutrition, 26, pp. 1–22. doi:10.1146/annurev.nutr.26.061505.111258
• Laffel, L. (1999) 'Ketone bodies: a review of physiology, pathophysiology and application of monitoring to diabetes', Diabetes/Metabolism Research and Reviews, 15(6), pp. 412–426. doi:10.1002/(SICI)1520-7560(199911/12)15:6<412::AID-DMRR72>3.0.CO;2-8

Ketones give more energy per unit of oxygen than glucose.

• Sato, K. et al. (1995) 'Insulin, ketone bodies, and mitochondrial energy transduction', FASEB Journal, 9(8), pp. 651–658. doi:10.1096/fasebj.9.8.7768357
• Veech, R.L. (2004) 'The therapeutic implications of ketone bodies: the effects of ketone bodies in pathological conditions: ketosis, ketogenic diet, redox states, insulin resistance, and mitochondrial metabolism', Prostaglandins, Leukotrienes and Essential Fatty Acids, 70(3), pp. 309–319. doi:10.1016/j.plefa.2003.09.007

Ketones improve mental performance and physical endurance.

• Cox, P.J. et al. (2016) 'Nutritional ketosis alters fuel preference and thereby endurance performance in athletes', Cell Metabolism, 24(2), pp. 256–268. doi:10.1016/j.cmet.2016.07.010

Dietary carbohydrate is not essential because the liver makes glucose (gluconeogenesis).

• Institute of Medicine (2005) Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academies Press. doi:10.17226/10490

Humans are adapted to stay in ketosis long-term, as the Inuit and nomadic tribes did.

• Clemente, F.J. et al. (2014) 'A selective sweep on a deleterious mutation in CPT1A in Arctic populations', American Journal of Human Genetics, 95(5), pp. 584–589. doi:10.1016/j.ajhg.2014.09.016
• Fumagalli, M. et al. (2015) 'Greenlandic Inuit show genetic signatures of diet and climate adaptation', Science, 349(6254), pp. 1343–1347. doi:10.1126/science.aab2319

Relying only on glucose can make the brain resistant to glucose and energy-starved, contributing to dementia.

• Cunnane, S.C. et al. (2016) 'Can ketones compensate for deteriorating brain glucose uptake during aging? Implications for the risk and treatment of Alzheimer's disease', Annals of the New York Academy of Sciences, 1367(1), pp. 12–20. doi:10.1111/nyas.12999

For decades a ketogenic diet has been recognised as effective for epilepsy.

• Neal, E.G. et al. (2008) 'The ketogenic diet for the treatment of childhood epilepsy: a randomised controlled trial', Lancet Neurology, 7(6), pp. 500–506. doi:10.1016/S1474-4422(08)70092-9
• Martin-McGill, K.J. et al. (2020) 'Ketogenic diets for drug-resistant epilepsy', Cochrane Database of Systematic Reviews, 6, CD001903. doi:10.1002/14651858.CD001903.pub5

A diet high in grains and fruit prevents ketone production.

• Feinman, R.D. et al. (2015) 'Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base', Nutrition, 31(1), pp. 1–13. doi:10.1016/j.nut.2014.06.011

Animal foods drove the growth of our brains beyond other primates.

• Aiello, L.C. and Wheeler, P. (1995) 'The expensive-tissue hypothesis: the brain and the digestive system in human and primate evolution', Current Anthropology, 36(2), pp. 199–221. doi:10.1086/204350

Many people can no longer switch easily between fuels (metabolic inflexibility).

• Goodpaster, B.H. and Sparks, L.M. (2017) 'Metabolic flexibility in health and disease', Cell Metabolism, 25(5), pp. 1027–1036. doi:10.1016/j.cmet.2017.04.015

The brain can become insulin resistant, causing an energy deficit linked to brain fog, dementia and Alzheimer's ("type 3 diabetes").

• Talbot, K. et al. (2012) 'Demonstrated brain insulin resistance in Alzheimer's disease patients is associated with IGF-1 resistance, IRS-1 dysregulation, and cognitive decline', Journal of Clinical Investigation, 122(4), pp. 1316–1338. doi:10.1172/JCI59903
• de la Monte, S.M. and Wands, J.R. (2008) 'Alzheimer's disease is type 3 diabetes—evidence reviewed', Journal of Diabetes Science and Technology, 2(6), pp. 1101–1113. doi:10.1177/193229680800200619

The brain is 60% fat.

• Chang, C.Y., Ke, D.S. and Chen, J.Y. (2009) 'Essential fatty acids and human brain', Acta Neurologica Taiwanica, 18(4), pp. 231–241. Available at: https://pubmed.ncbi.nlm.nih.gov/20329590/

Our ancestral diet is "unarguably" animal-based.

• Ben-Dor, M., Sirtoli, R. and Barkai, R. (2021) 'The evolution of the human trophic level during the Pleistocene', American Journal of Physical Anthropology, 175(Suppl 72), pp. 27–56. doi:10.1002/ajpa.24247
• Hardy, K. et al. (2015) 'The importance of dietary carbohydrate in human evolution', Quarterly Review of Biology, 90(3), pp. 251–268. doi:10.1086/682587

Fasting has helped people reverse chronic conditions including type 2 diabetes and rheumatoid arthritis.

• de Cabo, R. and Mattson, M.P. (2019) 'Effects of intermittent fasting on health, aging, and disease', New England Journal of Medicine, 381(26), pp. 2541–2551. doi:10.1056/NEJMra1905136
• Kjeldsen-Kragh, J. et al. (1991) 'Controlled trial of fasting and one-year vegetarian diet in rheumatoid arthritis', Lancet, 338(8772), pp. 899–902. doi:10.1016/0140-6736(91)91770-U

Fasting brings better insulin sensitivity (1), less abdominal fat (5), less inflammation (6), better brain function (4), and lower risk factors (8).

• de Cabo, R. and Mattson, M.P. (2019) 'Effects of intermittent fasting on health, aging, and disease', New England Journal of Medicine, 381(26), pp. 2541–2551. doi:10.1056/NEJMra1905136
• Sutton, E.F. et al. (2018) 'Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes', Cell Metabolism, 27(6), pp. 1212–1221.e3. doi:10.1016/j.cmet.2018.04.010
• Longo, V.D. and Mattson, M.P. (2014) 'Fasting: molecular mechanisms and clinical applications', Cell Metabolism, 19(2), pp. 181–192. doi:10.1016/j.cmet.2013.12.008
• Lowe, D.A. et al. (2020) 'Effects of time-restricted eating on weight loss and other metabolic parameters in women and men with overweight and obesity: the TREAT randomized clinical trial', JAMA Internal Medicine, 180(11), pp. 1491–1499. doi:10.1001/jamainternmed.2020.4153

Fasting slows bone-density loss (2), helps repair DNA (3), boosts the immune system (7) and increases lifespan (9).

• Longo, V.D. and Mattson, M.P. (2014) 'Fasting: molecular mechanisms and clinical applications', Cell Metabolism, 19(2), pp. 181–192. doi:10.1016/j.cmet.2013.12.008

Energy-dense, nutrient-poor refined foods drive overeating and ill health.

• Hall, K.D. et al. (2019) 'Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake', Cell Metabolism, 30(1), pp. 67–77.e3. doi:10.1016/j.cmet.2019.05.008

Weight gain and high insulin disrupt other hormones, so the brain senses starvation and saves energy.

• Myers, M.G. Jr et al. (2010) 'Obesity and leptin resistance: distinguishing cause from effect', Trends in Endocrinology & Metabolism, 21(11), pp. 643–651. doi:10.1016/j.tem.2010.08.002

Burning glucose creates "dirty smoke" (oxidation), which is the ageing process; ketones are a cleaner fuel.

• Veech, R.L. (2004) 'The therapeutic implications of ketone bodies: the effects of ketone bodies in pathological conditions: ketosis, ketogenic diet, redox states, insulin resistance, and mitochondrial metabolism', Prostaglandins, Leukotrienes and Essential Fatty Acids, 70(3), pp. 309–319. doi:10.1016/j.plefa.2003.09.007

Sucrose is glucose plus fructose, and sugars speed ageing by glycation ("browning").

• Monnier, V.M., Kohn, R.R. and Cerami, A. (1984) 'Accelerated age-related browning of human collagen in diabetes mellitus', Proceedings of the National Academy of Sciences USA, 81(2), pp. 583–587. doi:10.1073/pnas.81.2.583
• Uribarri, J. et al. (2010) 'Advanced glycation end products in foods and a practical guide to their reduction in the diet', Journal of the American Dietetic Association, 110(6), pp. 911–916.e12. doi:10.1016/j.jada.2010.03.018

Bones and collagen turn brown with age.

• Monnier, V.M., Kohn, R.R. and Cerami, A. (1984) 'Accelerated age-related browning of human collagen in diabetes mellitus', Proceedings of the National Academy of Sciences USA, 81(2), pp. 583–587. doi:10.1073/pnas.81.2.583

AGEs stiffen tissues, including arteries, the eye lens (cataracts) and skin (wrinkles).

• Goldin, A. et al. (2006) 'Advanced glycation end products: sparking the development of diabetic vascular injury', Circulation, 114(6), pp. 597–605. doi:10.1161/CIRCULATIONAHA.106.621854
• Gkogkolou, P. and Böhm, M. (2012) 'Advanced glycation end products: key players in skin aging?', Dermato-Endocrinology, 4(3), pp. 259–270. doi:10.4161/derm.22028

Rib-cartilage colour chart from infancy to 88 years.

• Monnier, V.M., Kohn, R.R. and Cerami, A. (1984) 'Accelerated age-related browning of human collagen in diabetes mellitus', Proceedings of the National Academy of Sciences USA, 81(2), pp. 583–587. doi:10.1073/pnas.81.2.583

Fructose ages us "much, much faster" than glucose.

• Bunn, H.F. and Higgins, P.J. (1981) 'Reaction of monosaccharides with proteins: possible evolutionary significance', Science, 213(4504), pp. 222–224. doi:10.1126/science.12192669

Sucrose is 50% glucose and 50% fructose; HFCS is an industrial sugar with many names.

• Stanhope, K.L. and Havel, P.J. (2008) 'Endocrine and metabolic effects of consuming beverages sweetened with fructose, glucose, sucrose, or high-fructose corn syrup', American Journal of Clinical Nutrition, 88(6), pp. 1733S–1737S. doi:10.3945/ajcn.2008.25825D

Only the liver can metabolise fructose, whereas every cell can use glucose.

• Jang, C. et al. (2018) 'The small intestine converts dietary fructose into glucose and organic acids', Cell Metabolism, 27(2), pp. 351–361.e3. doi:10.1016/j.cmet.2017.12.016

Fructose overload causes fatty liver and drives insulin resistance and weight gain.

• Stanhope, K.L. et al. (2009) 'Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans', Journal of Clinical Investigation, 119(5), pp. 1322–1334. doi:10.1172/JCI37385
• Chung, M. et al. (2014) 'Fructose, high-fructose corn syrup, sucrose, and nonalcoholic fatty liver disease or indexes of liver health: a systematic review and meta-analysis', American Journal of Clinical Nutrition, 100(3), pp. 833–849. doi:10.3945/ajcn.114.086314

Lustig's study in obese children with metabolic syndrome, with sugar cut from 28% to 10% of calories and replaced by starch; the children were not meant to lose weight.

• Lustig, R.H. et al. (2016) 'Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome', Obesity, 24(2), pp. 453–460. doi:10.1002/oby.21371

Metabolic syndrome is 3 or more of 5 criteria, including "waist circumference over half of height".

• Alberti, K.G. et al. (2009) 'Harmonizing the metabolic syndrome: a joint interim statement…', Circulation, 120(16), pp. 1640–1645. doi:10.1161/CIRCULATIONAHA.109.192644

Metabolic syndrome indicates low immunity and poor resistance to infection.

• Critchley, J.A. et al. (2018) 'Glycemic control and risk of infections among people with type 1 or type 2 diabetes in a large primary care cohort study', Diabetes Care, 41(10), pp. 2127–2135. doi:10.2337/dc18-0287

Triglycerides fell 46%.

• Lustig, R.H. et al. (2016) 'Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome', Obesity, 24(2), pp. 453–460. doi:10.1002/oby.21371

Visceral fat fell 7% and liver fat fell 22%.

• Schwarz, J.M. et al. (2017) 'Effects of dietary fructose restriction on liver fat, de novo lipogenesis, and insulin kinetics in children with obesity', Gastroenterology, 153(3), pp. 743–752. doi:10.1053/j.gastro.2017.05.043

Fructose leads to significantly faster weight gain than glucose.

• Chung, M. et al. (2014) 'Fructose, high-fructose corn syrup, sucrose, and nonalcoholic fatty liver disease or indexes of liver health: a systematic review and meta-analysis', American Journal of Clinical Nutrition, 100(3), pp. 833–849. doi:10.3945/ajcn.114.086314

Sugar releases dopamine "just like cocaine" and is the number-one driver of cravings.

• Avena, N.M., Rada, P. and Hoebel, B.G. (2008) 'Evidence for sugar addiction: behavioral and neurochemical effects of intermittent, excessive sugar intake', Neuroscience & Biobehavioral Reviews, 32(1), pp. 20–39. doi:10.1016/j.neubiorev.2007.04.019
• Westwater, M.L., Fletcher, P.C. and Ziauddeen, H. (2016) 'Sugar addiction: the state of the science', European Journal of Nutrition, 55(Suppl 2), pp. 55–69. doi:10.1007/s00394-016-1229-6

Blood-sugar dips after a spike bring hunger back.

• Wyatt, P. et al. (2021) 'Postprandial glycaemic dips predict appetite and energy intake in healthy individuals', Nature Metabolism, 3(4), pp. 523–529. doi:10.1038/s42255-021-00383-x

Insulin resistance disrupts ghrelin (hunger) and PYY (fullness) signalling, and fixing it helps.

• Batterham, R.L. et al. (2003) 'Inhibition of food intake in obese subjects by peptide YY3-36', New England Journal of Medicine, 349(10), pp. 941–948. doi:10.1056/NEJMoa030204
• McLaughlin, T. et al. (2004) 'Plasma ghrelin concentrations are decreased in insulin-resistant obese adults relative to equally obese insulin-sensitive controls', Journal of Clinical Endocrinology & Metabolism, 89(4), pp. 1630–1635. doi:10.1210/jc.2003-031572

Fat tissue produces leptin; excess fat makes too much leptin, and the brain becomes resistant (leptin resistance), causing hunger and lethargy.

• Considine, R.V. et al. (1996) 'Serum immunoreactive-leptin concentrations in normal-weight and obese humans', New England Journal of Medicine, 334(5), pp. 292–295. doi:10.1056/NEJM199602013340503
• Myers, M.G. Jr et al. (2010) 'Obesity and leptin resistance: distinguishing cause from effect', Trends in Endocrinology & Metabolism, 21(11), pp. 643–651. doi:10.1016/j.tem.2010.08.002

Iron is needed to make serotonin and dopamine, and iron deficiency lowers mood.

• Kim, J. and Wessling-Resnick, M. (2014) 'Iron and mechanisms of emotional behavior', Journal of Nutritional Biochemistry, 25(11), pp. 1101–1107. doi:10.1016/j.jnutbio.2014.07.003

Heavy periods and blood loss in childbirth cause iron deficiency and post-natal low mood.

• Beard, J.L. et al. (2005) 'Maternal iron deficiency anemia affects postpartum emotions and cognition', Journal of Nutrition, 135(2), pp. 267–272. doi:10.1093/jn/135.2.267
• NHS (n.d.) Iron deficiency anaemia. Available at: https://www.nhs.uk/conditions/iron-deficiency-anaemia/

Red meat has more easily absorbed haem iron than chicken or fish; plant non-haem iron is less well absorbed.

• Hurrell, R. and Egli, I. (2010) 'Iron bioavailability and dietary reference values', American Journal of Clinical Nutrition, 91(5), pp. 1461S–1467S. doi:10.3945/ajcn.2010.28674F

In chronic inflammation the body "hides" iron from pathogens (via hepcidin), even when iron stores are adequate.

• Weiss, G., Ganz, T. and Goodnough, L.T. (2019) 'Anemia of inflammation', Blood, 133(1), pp. 40–50. doi:10.1182/blood-2018-06-856500

Western guidelines have favoured low-fat, high-carbohydrate diets and polyunsaturated seed oils.

• Sacks, F.M. et al. (2017) 'Dietary fats and cardiovascular disease: a presidential advisory from the American Heart Association', Circulation, 136(3), pp. e1–e23. doi:10.1161/CIR.0000000000000510

PUFA seed oils were an early-20th-century invention, very new in the human diet.

• Blasbalg, T.L. et al. (2011) 'Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century', American Journal of Clinical Nutrition, 93(5), pp. 950–962. doi:10.3945/ajcn.110.006643

Procter & Gamble, soap makers in Cincinnati, turned surplus "toxic waste" cottonseed oil into a product.

• Ramsey, D. and Graham, T. (2012) 'How vegetable oils replaced animal fats in the American diet', The Atlantic, 26 April. Available at: https://www.theatlantic.com/health/archive/2012/04/how-vegetable-oils-replaced-animal-fats-in-the-american-diet/256155/

P&G used hydrogenation to turn cottonseed oil into a lard-like solid fat (Crisco, 1911).

• Ramsey, D. and Graham, T. (2012) 'How vegetable oils replaced animal fats in the American diet', The Atlantic, 26 April. Available at: https://www.theatlantic.com/health/archive/2012/04/how-vegetable-oils-replaced-animal-fats-in-the-american-diet/256155/
• Mozaffarian, D. et al. (2006) 'Trans fatty acids and cardiovascular disease', New England Journal of Medicine, 354(15), pp. 1601–1613. doi:10.1056/NEJMra054035

Repeatedly heating PUFA oils creates toxic compounds (aldehydes).

• Katragadda, H.R. et al. (2010) 'Emissions of volatile aldehydes from heated cooking oils', Food Chemistry, 120(1), pp. 59–65. doi:10.1016/j.foodchem.2009.09.070
• Esterbauer, H., Schaur, R.J. and Zollner, H. (1991) 'Chemistry and biochemistry of 4-hydroxynonenal, malonaldehyde and related aldehydes', Free Radical Biology & Medicine, 11(1), pp. 81–128. doi:10.1016/0891-5849(91)90192-6

Saturated fat protects the liver from alcohol, while PUFA oils make alcohol more toxic to the liver.

• Nanji, A.A. et al. (1995) 'Dietary saturated fatty acids: a novel treatment for alcoholic liver disease', Gastroenterology, 109(2), pp. 547–554. doi:10.1016/0016-5085(95)90344-5

"Polyunsaturated fat is healthier than saturated fat" has caused overwhelming suffering.

• Hooper, L. et al. (2020) 'Reduction in saturated fat intake for cardiovascular disease', Cochrane Database of Systematic Reviews, 8, CD011737. doi:10.1002/14651858.CD011737.pub3

Saturated animal fat is rich in vitamins A, D, E and K.

• Daley, C.A. et al. (2010) 'A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef', Nutrition Journal, 9, 10. doi:10.1186/1475-2891-9-10

A ribeye serving with 10.8 g total fat has 4.2 g saturated, 4.4 g monounsaturated and 0.4 g polyunsaturated fat.

• U.S. Department of Agriculture, Agricultural Research Service (2019–) FoodData Central. Available at: https://fdc.nal.usda.gov/

Omega-6 is pro-inflammatory, omega-3 anti-inflammatory, and current intake of omega-6 drives weight gain and inflammatory disease.

• Johnson, G.H. and Fritsche, K. (2012) 'Effect of dietary linoleic acid on markers of inflammation in healthy persons: a systematic review of randomized controlled trials', Journal of the Academy of Nutrition and Dietetics, 112(7), pp. 1029–1041.e15. doi:10.1016/j.jand.2012.03.029
• Innes, J.K. and Calder, P.C. (2018) 'Omega-6 fatty acids and inflammation', Prostaglandins, Leukotrienes and Essential Fatty Acids, 132, pp. 41–48. doi:10.1016/j.plefa.2018.03.004

Omega-6 consumption has soared since seed oils were introduced.

• Blasbalg, T.L. et al. (2011) 'Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century', American Journal of Clinical Nutrition, 93(5), pp. 950–962. doi:10.3945/ajcn.110.006643

The ancestral omega-3 to omega-6 ratio was about 1:2, and today it is up to 1:20.

• Simopoulos, A.P. (2002) 'The importance of the ratio of omega-6/omega-3 essential fatty acids', Biomedicine & Pharmacotherapy, 56(8), pp. 365–379. doi:10.1016/S0753-3322(02)00253-6

One portion of oily fish twice a week would give a good balance.

• NHS (n.d.) Fish and shellfish. Available at: https://www.nhs.uk/live-well/eat-well/food-types/fish-and-shellfish-nutrition/

A campaign by millionaire Phil Sokolof led McDonald's to drop beef tallow for its fries in 1990.

• UPI (1990) 'After eight years of study, McDonald's has decided to cook its french fries in vegetable oil', UPI Archives, 23 July. Available at: https://www.upi.com/Archives/1990/07/23/After-eight-years-of-study-McDonalds-has-decided-to/7166648705600/

Saturated fats are solid at room temperature and stable when cooked; unsaturated fats oxidise more easily.

• Katragadda, H.R. et al. (2010) 'Emissions of volatile aldehydes from heated cooking oils', Food Chemistry, 120(1), pp. 59–65. doi:10.1016/j.foodchem.2009.09.070

Olive and avocado oil are best used unheated.

• de Alzaa, F., Guillaume, C. and Ravetti, L. (2021) 'Evaluation of chemical and nutritional changes in chips, chicken nuggets, and broccoli after deep-frying with extra virgin olive oil, canola, and grapeseed oils', Journal of Food Quality, 2021, 7319013. doi:10.1155/2021/7319013

Omega-3 sources are oily fish and flaxseed; omega-6 sources are walnut, soy, corn and sesame oils.

• Simopoulos, A.P. (2002) 'The importance of the ratio of omega-6/omega-3 essential fatty acids', Biomedicine & Pharmacotherapy, 56(8), pp. 365–379. doi:10.1016/S0753-3322(02)00253-6

Fat from grain-fed single-stomach animals (chicken, pork) is higher in PUFA; ruminant fat is more saturated.

• Wood, J.D. et al. (2008) 'Fat deposition, fatty acid composition and meat quality: a review', Meat Science, 78(4), pp. 343–358. doi:10.1016/j.meatsci.2007.07.019

The evidence clearly tells us to sharply limit omega-6 as a matter of urgency.

• Marklund, M. et al. (2019) 'Biomarkers of dietary omega-6 fatty acids and incident cardiovascular disease and mortality', Circulation, 139(21), pp. 2422–2436. doi:10.1161/CIRCULATIONAHA.118.038908
• Farvid, M.S. et al. (2014) 'Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies', Circulation, 130(18), pp. 1568–1578. doi:10.1161/CIRCULATIONAHA.114.010236

Food labels show saturated fat but not the breakdown into omega-6, omega-3 and monounsaturated fat.

• Regulation (EU) No 1169/2011 on the provision of food information to consumers (retained UK law), Article 30 and Annex XV. Available at: https://www.legislation.gov.uk/eur/2011/1169/contents

Linoleic acid is unstable and oxidises in the body and when heated.

• Esterbauer, H., Schaur, R.J. and Zollner, H. (1991) 'Chemistry and biochemistry of 4-hydroxynonenal, malonaldehyde and related aldehydes', Free Radical Biology & Medicine, 11(1), pp. 81–128. doi:10.1016/0891-5849(91)90192-6

Seed oils drive insulin resistance and chronic inflammation.

• Imamura, F. et al. (2016) 'Effects of saturated fat, polyunsaturated fat, monounsaturated fat, and carbohydrate on glucose-insulin homeostasis: a systematic review and meta-analysis of randomised controlled feeding trials', PLoS Medicine, 13(7), e1002087. doi:10.1371/journal.pmed.1002087
• Johnson, G.H. and Fritsche, K. (2012) 'Effect of dietary linoleic acid on markers of inflammation in healthy persons: a systematic review of randomized controlled trials', Journal of the Academy of Nutrition and Dietetics, 112(7), pp. 1029–1041.e15. doi:10.1016/j.jand.2012.03.029

Oxidised seed oils damage LDL, and LDL quality, not quantity, matters.

• Parthasarathy, S. et al. (1990) 'Low density lipoprotein rich in oleic acid is protected against oxidative modification: implications for dietary prevention of atherosclerosis', Proceedings of the National Academy of Sciences USA, 87(10), pp. 3894–3898. doi:10.1073/pnas.87.10.3894
• Ference, B.A. et al. (2017) 'Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel', European Heart Journal, 38(32), pp. 2459–2472. doi:10.1093/eurheartj/ehx144

HNE from oxidised omega-6 is a mutagen that damages the p53 anti-cancer gene; p53 is damaged in about 50% of cancers.

• Hu, W. et al. (2002) 'The major lipid peroxidation product, trans-4-hydroxy-2-nonenal, preferentially forms DNA adducts at codon 249 of human p53 gene, a unique mutational hotspot in hepatocellular carcinoma', Carcinogenesis, 23(11), pp. 1781–1789. doi:10.1093/carcin/23.11.1781
• Hollstein, M. et al. (1991) 'p53 mutations in human cancers', Science, 253(5015), pp. 49–53. doi:10.1126/science.1905840

This may explain the "massive increase in cancer in the last 120 years".

• Cancer Research UK (n.d.) Cancer mortality statistics. Available at: https://www.cancerresearchuk.org/health-professional/cancer-statistics/mortality

Linoleic acid stays in tissue for up to about two years.

• Hodson, L., Skeaff, C.M. and Fielding, B.A. (2008) 'Fatty acid composition of adipose tissue and blood in humans and its use as a biomarker of dietary intake', Progress in Lipid Research, 47(5), pp. 348–380. doi:10.1016/j.plipres.2008.03.003
• Dayton, S. et al. (1966) 'Composition of lipids in human serum and adipose tissue during prolonged feeding of a diet high in unsaturated fat', Journal of Lipid Research, 7(1), pp. 103–111. doi:10.1016/S0022-2275(20)39591-2

Ventilated Covid-19 patients are tube-fed ("parenteral nutrition") with omega-6 seed-oil fats, which may worsen outcomes.

• Calder, P.C. (2013) 'Lipids for intravenous nutrition in hospitalised adult patients: a multiple choice of options', Proceedings of the Nutrition Society, 72(3), pp. 263–276. doi:10.1017/S0029665113001250

Ramsden (2016, NIH) re-examined 9,400 people from the 1968–73 Minnesota Coronary Experiment and concluded that meat and dairy fats should never have been demonised.

• Ramsden, C.E. et al. (2016) 'Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968–73)', BMJ, 353, i1246. doi:10.1136/bmj.i1246

Soybean-oil intake rose from 1–3% to 15–20% of energy worldwide.

• Blasbalg, T.L. et al. (2011) 'Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century', American Journal of Clinical Nutrition, 93(5), pp. 950–962. doi:10.3945/ajcn.110.006643

Omega-6 lowers LDL cholesterol.

• Ramsden, C.E. et al. (2016) 'Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968–73)', BMJ, 353, i1246. doi:10.1136/bmj.i1246

LDL is vital and recycled by the body (LDL receptor).

• Brown, M.S. and Goldstein, J.L. (1986) 'A receptor-mediated pathway for cholesterol homeostasis', Science, 232(4746), pp. 34–47. doi:10.1126/science.3513311

High LDL is common in centenarians.

• Ravnskov, U. et al. (2016) 'Lack of an association or an inverse association between low-density-lipoprotein cholesterol and mortality in the elderly: a systematic review', BMJ Open, 6(6), e010401. doi:10.1136/bmjopen-2015-010401

Heart-attack patients are as likely to have low LDL as high.

• Sachdeva, A. et al. (2009) 'Lipid levels in patients hospitalized with coronary artery disease: an analysis of 136,905 hospitalizations in Get With The Guidelines', American Heart Journal, 157(1), pp. 111–117.e2. doi:10.1016/j.ahj.2008.08.010

The problem is damaged LDL, not high LDL, so there is no need for statins.

• Ference, B.A. et al. (2017) 'Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel', European Heart Journal, 38(32), pp. 2459–2472. doi:10.1093/eurheartj/ehx144
• Cholesterol Treatment Trialists' (CTT) Collaboration (2010) 'Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170,000 participants in 26 randomised trials', Lancet, 376(9753), pp. 1670–1681. doi:10.1016/S0140-6736(10)61350-5

Thompson et al. (2019), Current Anthropology, "Origins of the human predatory pattern", propose that early hominins got fat-rich marrow and brain by pounding scavenged bones and skulls with stones, before hunting.

• Thompson, J.C. et al. (2019) 'Origins of the human predatory pattern: the transition to large-animal exploitation by early hominins', Current Anthropology, 60(1), pp. 1–23. doi:10.1086/701477

Amber O'Hearn developed the idea further.

• O'Hearn, A. (2020) 'Can a carnivore diet provide all essential nutrients?', Current Opinion in Endocrinology, Diabetes and Obesity, 27(5), pp. 312–316. doi:10.1097/MED.0000000000000576

Stone tools may have come from rocks splintering while pounding bones.

• Thompson, J.C. et al. (2019) 'Origins of the human predatory pattern: the transition to large-animal exploitation by early hominins', Current Anthropology, 60(1), pp. 1–23. doi:10.1086/701477

A fat-rich diet let our guts shrink and our brains grow (expensive tissue).

• Aiello, L.C. and Wheeler, P. (1995) 'The expensive-tissue hypothesis: the brain and the digestive system in human and primate evolution', Current Anthropology, 36(2), pp. 199–221. doi:10.1086/204350

Our ancestors hunted large, fatty animals, and the woolly rhinoceros and Glyptodon were hunted to extinction.

• Ben-Dor, M., Sirtoli, R. and Barkai, R. (2021) 'The evolution of the human trophic level during the Pleistocene', American Journal of Physical Anthropology, 175(Suppl 72), pp. 27–56. doi:10.1002/ajpa.24247
• Politis, G.G. et al. (2019) 'Campo Laborde: a Late Pleistocene giant ground sloth kill and butchering site in the Pampas', Science Advances, 5(3), eaau4546. doi:10.1126/sciadv.aau4546
• Lord, E. et al. (2020) 'Pre-extinction demographic stability and genomic signatures of adaptation in the woolly rhinoceros', Current Biology, 30(19), pp. 3871–3879.e7. doi:10.1016/j.cub.2020.07.046

For over 50 years, guidelines have put fat at the top of the pyramid and carbohydrates at the base.

• Harcombe, Z. et al. (2015) 'Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis', Open Heart, 2(1), e000196. doi:10.1136/openhrt-2014-000196

Carbohydrate is the nutrient that "leads to" type 2 diabetes and that diabetics cannot cope with.

• Feinman, R.D. et al. (2015) 'Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base', Nutrition, 31(1), pp. 1–13. doi:10.1016/j.nut.2014.06.011

Government guidelines advise 260–375 g of carbohydrate a day.

• Regulation (EU) No 1169/2011 on the provision of food information to consumers (retained UK law), Article 30 and Annex XV. Available at: https://www.legislation.gov.uk/eur/2011/1169/contents
• Scientific Advisory Committee on Nutrition (2015) Carbohydrates and Health. London: TSO. Available at: https://www.gov.uk/government/publications/sacn-carbohydrates-and-health-report

Ketosis needs a maximum of 20–100 g of carbohydrate, depending on fitness.

• Feinman, R.D. et al. (2015) 'Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base', Nutrition, 31(1), pp. 1–13. doi:10.1016/j.nut.2014.06.011

The 2020 PHE Eatwell Plate advises 70% carbohydrate, 20% protein and 10% fat.

• Public Health England (2016) From Plate to Guide: What, why and how for the eatwell model. London: PHE. Available at: https://assets.publishing.service.gov.uk/media/5a7f73f7e5274a2e8ab4c461/eatwell_model_guide_report.pdf
• Scarborough, P. et al. (2016) 'Eatwell Guide: modelling the dietary and cost implications of incorporating new sugar and fibre guidelines', BMJ Open, 6(12), e013182. doi:10.1136/bmjopen-2016-013182
• NHS (n.d.) The Eatwell Guide. Available at: https://www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/the-eatwell-guide/

65% of 2,000 kcal from fat is about 145 g of fat a day.

• FAO (2003) Food energy – methods of analysis and conversion factors. FAO Food and Nutrition Paper 77. Rome: FAO. Available at: https://www.fao.org/4/Y5022E/y5022e04.htm

Reduce dietary fat during weight loss so more body fat is burned.

• Hall, K.D. et al. (2015) 'Calorie for calorie, dietary fat restriction results in more body fat loss than carbohydrate restriction in people with obesity', Cell Metabolism, 22(3), pp. 427–436. doi:10.1016/j.cmet.2015.07.021

Food fat contents (butter 40 g, 2 eggs 10 g, 50 ml double cream 25 g, etc.).

• U.S. Department of Agriculture, Agricultural Research Service (2019–) FoodData Central. Available at: https://fdc.nal.usda.gov/

Bears use insulin to fatten before hibernation, then become thin.

• Rigano, K.S. et al. (2017) 'Life in the fat lane: seasonal regulation of insulin sensitivity, food intake, and adipose biology in brown bears', Journal of Comparative Physiology B, 187(4), pp. 649–676. doi:10.1007/s00360-016-1050-9

Birds fatten on sweet berries in late summer before migrating.

• Bairlein, F. (2002) 'How to get fat: nutritional mechanisms of seasonal fat accumulation in migratory songbirds', Naturwissenschaften, 89(1), pp. 1–10. doi:10.1007/s00114-001-0279-6

Early farmers had worse bone and dental health, nutrient deficiencies (iron, protein, vitamin A), and were shorter than Palaeolithic hunter-gatherers.

• Larsen, C.S. (1995) 'Biological changes in human populations with agriculture', Annual Review of Anthropology, 24, pp. 185–213. doi:10.1146/annurev.an.24.100195.001153
• Mummert, A. et al. (2011) 'Stature and robusticity during the agricultural transition: evidence from the bioarchaeological record', Economics & Human Biology, 9(3), pp. 284–301. doi:10.1016/j.ehb.2011.03.004

Marc Armand Ruffer, a pioneer of palaeopathology, found arterial disease in Egyptian mummies; heart disease, arthritis and bad teeth were common.

• Ruffer, M.A. (1911) 'On arterial lesions found in Egyptian mummies (1580 B.C.–525 A.D.)', Journal of Pathology and Bacteriology, 15(4), pp. 453–462. doi:10.1002/path.1700150403
• Allam, A.H. et al. (2009) 'Computed tomographic assessment of atherosclerosis in ancient Egyptian mummies', JAMA, 302(19), pp. 2091–2094. doi:10.1001/jama.2009.1641

Grain caused the heart disease seen in Egyptian mummies.

• Thompson, R.C. et al. (2013) 'Atherosclerosis across 4000 years of human history: the Horus study of four ancient populations', Lancet, 381(9873), pp. 1211–1222. doi:10.1016/S0140-6736(13)60598-X

Quote from Dr Ron Rosedale.

• Rosedale, R. (n.d.) The critical connection between protein, cancer, aging and TOR [lecture handout]. Available at: https://ofm.io/wp-content/uploads/2022/03/Ron-Rosedale-The-Critical-Connection-Between-Protein-Cancer-Aging-and-TOR.pdf

Infant death rates in the West have fallen dramatically in the last 120 years, pushing up life expectancy.

• Roser, M., Ritchie, H. and Dadonaite, B. (2019) Child and infant mortality. Our World in Data. Available at: https://ourworldindata.org/child-mortality

The Japanese eat a very low-carb meat and fish diet.

• Ministry of Health, Labour and Welfare, Japan (2020) Dietary Reference Intakes for Japanese (2020). Available at: https://www.mhlw.go.jp/content/001151422.pdf
• Willcox, D.C. et al. (2009) 'The Okinawan diet: health implications of a low-calorie, nutrient-dense, antioxidant-rich dietary pattern low in glycemic load', Journal of the American College of Nutrition, 28(Suppl 4), pp. 500S–516S. doi:10.1080/07315724.2009.10718117

The "French paradox" (low heart disease despite high saturated fat) has been quietly ignored.

• Renaud, S. and de Lorgeril, M. (1992) 'Wine, alcohol, platelets, and the French paradox for coronary heart disease', Lancet, 339(8808), pp. 1523–1526. doi:10.1016/0140-6736(92)91277-F
• Law, M. and Wald, N. (1999) 'Why heart disease mortality is low in France: the time lag explanation', BMJ, 318(7196), pp. 1471–1476. doi:10.1136/bmj.318.7196.1471

A study of WHO statistics found that people living past 100 share high cholesterol and low insulin.

• Paolisso, G. et al. (1996) 'Glucose tolerance and insulin action in healthy centenarians', American Journal of Physiology, 270(5 Pt 1), pp. E890–E894. doi:10.1152/ajpendo.1996.270.5.E890
• Paolisso, G. et al. (1997) 'Preserved antilipolytic insulin action is associated with a less atherogenic plasma lipid profile in healthy centenarians', Journal of the American Geriatrics Society, 45(12), pp. 1504–1509. doi:10.1111/j.1532-5415.1997.tb03203.x

Heart-attack patients are equally likely to have high or low cholesterol.

• Sachdeva, A. et al. (2009) 'Lipid levels in patients hospitalized with coronary artery disease: an analysis of 136,905 hospitalizations in Get With The Guidelines', American Heart Journal, 157(1), pp. 111–117.e2. doi:10.1016/j.ahj.2008.08.010

Ancel Keys' diet–heart hypothesis is "debunked" and based on cherry-picked data.

• Harcombe, Z. et al. (2015) 'Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis', Open Heart, 2(1), e000196. doi:10.1136/openhrt-2014-000196
• Pett, K.D. et al. (2017) 'The Seven Countries Study', European Heart Journal, 38(42), pp. 3119–3121. doi:10.1093/eurheartj/ehx603
• Ference, B.A. et al. (2017) 'Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel', European Heart Journal, 38(32), pp. 2459–2472. doi:10.1093/eurheartj/ehx144

Sugar and oils damage LDL, which "takes the hit"; so cut these rather than take statins.

• Cholesterol Treatment Trialists' (CTT) Collaboration (2010) 'Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170,000 participants in 26 randomised trials', Lancet, 376(9753), pp. 1670–1681. doi:10.1016/S0140-6736(10)61350-5

We make most of our cholesterol and recycle it; the brain uses nearly a third of the body's supply.

• Dietschy, J.M. and Turley, S.D. (2004) 'Thematic review series: brain lipids. Cholesterol metabolism in the central nervous system during early development and in the mature animal', Journal of Lipid Research, 45(8), pp. 1375–1397. doi:10.1194/jlr.R400004-JLR200

LDL delivers energy to every cell.

• Brown, M.S. and Goldstein, J.L. (1986) 'A receptor-mediated pathway for cholesterol homeostasis', Science, 232(4746), pp. 34–47. doi:10.1126/science.3513311

LDL cholesterol is needed to make vitamin D and hormones, supports the immune system and protects against infection.

• Netea, M.G. et al. (1996) 'Low-density lipoprotein receptor-deficient mice are protected against lethal endotoxemia and severe gram-negative infections', Journal of Clinical Investigation, 97(6), pp. 1366–1372. doi:10.1172/JCI118556

Sugar and oxidised oils turn LDL from large "fluffy" particles into small dense ones that enter the artery wall and form plaque.

• Austin, M.A. et al. (1988) 'Low-density lipoprotein subclass patterns and risk of myocardial infarction', JAMA, 260(13), pp. 1917–1921. doi:10.1001/jama.1988.03410130125037
• Krauss, R.M. et al. (2006) 'Separate effects of reduced carbohydrate intake and weight loss on atherogenic dyslipidemia', American Journal of Clinical Nutrition, 83(5), pp. 1025–1031. doi:10.1093/ajcn/83.5.1025
• Tabas, I., Williams, K.J. and Borén, J. (2007) 'Subendothelial lipoprotein retention as the initiating process in atherosclerosis', Circulation, 116(16), pp. 1832–1844. doi:10.1161/CIRCULATIONAHA.106.676890

No well-designed conclusive study has shown red meat to be harmful.

• Johnston, B.C. et al. (2019) 'Unprocessed red meat and processed meat consumption: dietary guideline recommendations from the Nutritional Recommendations (NutriRECS) Consortium', Annals of Internal Medicine, 171(10), pp. 756–764. doi:10.7326/M19-1621
• Bouvard, V. et al. (2015) 'Carcinogenicity of consumption of red and processed meat', Lancet Oncology, 16(16), pp. 1599–1600. doi:10.1016/S1470-2045(15)00444-1

The expensive-tissue hypothesis: we traded gut size for brain size as we ate more animal food; the colon shortened and the small intestine lengthened compared with other primates.

• Aiello, L.C. and Wheeler, P. (1995) 'The expensive-tissue hypothesis: the brain and the digestive system in human and primate evolution', Current Anthropology, 36(2), pp. 199–221. doi:10.1086/204350

Epidemiology shows correlation, not causation; food-frequency questionnaires are prone to recall error.

• Ioannidis, J.P.A. (2018) 'The challenge of reforming nutritional epidemiologic research', JAMA, 320(10), pp. 969–970. doi:10.1001/jama.2018.11025
• Archer, E., Marlow, M.L. and Lavie, C.J. (2018) 'Controversy and debate: Memory-Based Methods Paper 1: the fatal flaws of food frequency questionnaires and other memory-based dietary assessment methods', Journal of Clinical Epidemiology, 104, pp. 113–124. doi:10.1016/j.jclinepi.2018.08.003

Studies suffer from "healthy user" and "unhealthy user" bias.

• Shrank, W.H., Patrick, A.R. and Brookhart, M.A. (2011) 'Healthy user and related biases in observational studies of preventive interventions: a primer for physicians', Journal of General Internal Medicine, 26(5), pp. 546–550. doi:10.1007/s11606-010-1609-1

Asian studies of red meat give conflicting results compared with Western ones.

• Lee, J.E. et al. (2013) 'Meat intake and cause-specific mortality: a pooled analysis of Asian prospective cohort studies', American Journal of Clinical Nutrition, 98(4), pp. 1032–1041. doi:10.3945/ajcn.113.062638

The traditional Mediterranean diet was a nose-to-tail animal diet rich in cheese.

• Willett, W.C. et al. (1995) 'Mediterranean diet pyramid: a cultural model for healthy eating', American Journal of Clinical Nutrition, 61(6 Suppl), pp. 1402S–1406S. doi:10.1093/ajcn/61.6.1402S
• Nestle, M. (1995) 'Mediterranean diets: historical and research overview', American Journal of Clinical Nutrition, 61(6 Suppl), pp. 1313S–1320S. doi:10.1093/ajcn/61.6.1313S

Cooking regularly at home supports a healthier diet.

• Wolfson, J.A. and Bleich, S.N. (2015) 'Is cooking at home associated with better diet quality or weight-loss intention?', Public Health Nutrition, 18(8), pp. 1397–1406. doi:10.1017/S1368980014001943

Corn and grain feeding raise the PUFA content of chicken and pork fat.

• Wood, J.D. et al. (2008) 'Fat deposition, fatty acid composition and meat quality: a review', Meat Science, 78(4), pp. 343–358. doi:10.1016/j.meatsci.2007.07.019

Eggs are "nature's multivitamin".

• Réhault-Godbert, S., Guyot, N. and Nys, Y. (2019) 'The golden egg: nutritional value, bioactivities, and emerging benefits for human health', Nutrients, 11(3), 684. doi:10.3390/nu11030684

Smaller fish have lower heavy-metal levels, and eating a lot of tuna can build up mercury.

• NHS (n.d.) Fish and shellfish. Available at: https://www.nhs.uk/live-well/eat-well/food-types/fish-and-shellfish-nutrition/

Shellfish are rich in minerals.

• NHS (n.d.) Fish and shellfish. Available at: https://www.nhs.uk/live-well/eat-well/food-types/fish-and-shellfish-nutrition/

Green vegetables always contain magnesium, because chlorophyll cannot form without it.

• National Institutes of Health, Office of Dietary Supplements (n.d.) Magnesium: fact sheet for health professionals. Available at: https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/

Fermentation raises vitamin content, reduces anti-nutrients and "pre-digests" vegetables, which may help IBS.

• Marco, M.L. et al. (2017) 'Health benefits of fermented foods: microbiota and beyond', Current Opinion in Biotechnology, 44, pp. 94–102. doi:10.1016/j.copbio.2016.11.010

Olive oil is best served unheated.

• de Alzaa, F., Guillaume, C. and Ravetti, L. (2021) 'Evaluation of chemical and nutritional changes in chips, chicken nuggets, and broccoli after deep-frying with extra virgin olive oil, canola, and grapeseed oils', Journal of Food Quality, 2021, 7319013. doi:10.1155/2021/7319013

Muscle can take up glucose without insulin (during contraction), and more muscle means more glucose storage.

• Richter, E.A. and Hargreaves, M. (2013) 'Exercise, GLUT4, and skeletal muscle glucose uptake', Physiological Reviews, 93(3), pp. 993–1017. doi:10.1152/physrev.00038.2012

The liver stores about 100 g of glycogen (400 kcal).

• Gonzalez, J.T. et al. (2016) 'Liver glycogen metabolism during and after prolonged endurance-type exercise', American Journal of Physiology – Endocrinology and Metabolism, 311(3), pp. E543–E553. doi:10.1152/ajpendo.00232.2016

When the liver is full it converts extra carbohydrate to fat.

• Acheson, K.J. et al. (1988) 'Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man', American Journal of Clinical Nutrition, 48(2), pp. 240–247. doi:10.1093/ajcn/48.2.240

Muscle glycogen serves only the muscle.

• Richter, E.A. and Hargreaves, M. (2013) 'Exercise, GLUT4, and skeletal muscle glucose uptake', Physiological Reviews, 93(3), pp. 993–1017. doi:10.1152/physrev.00038.2012

Liver glycogen must be used up before fat can be burned.

• Rothman, D.L. et al. (1991) 'Quantitation of hepatic glycogenolysis and gluconeogenesis in fasting humans with 13C NMR', Science, 254(5031), pp. 573–576. doi:10.1126/science.1948033

Training to failure is important because it signals muscle to grow.

• Grgic, J. et al. (2022) 'Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: a systematic review and meta-analysis', Journal of Sport and Health Science, 11(2), pp. 202–211. doi:10.1016/j.jshs.2021.01.007

Muscle loss with age causes frailty, falls and fractures, a major cause of death in old age.

• Cruz-Jentoft, A.J. et al. (2019) 'Sarcopenia: revised European consensus on definition and diagnosis', Age and Ageing, 48(1), pp. 16–31. doi:10.1093/ageing/afy169
• World Health Organization (2021) Falls [fact sheet], 26 April. Available at: https://www.who.int/news-room/fact-sheets/detail/falls

Strength training and more protein reduce frailty.

• Cermak, N.M. et al. (2012) 'Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysis', American Journal of Clinical Nutrition, 96(6), pp. 1454–1464. doi:10.3945/ajcn.112.037556
• Bauer, J. et al. (2013) 'Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group', Journal of the American Medical Directors Association, 14(8), pp. 542–559. doi:10.1016/j.jamda.2013.05.021

Overfilled fat cells spill fat into the liver, blood vessels and heart; people differ in whether fat cells enlarge or multiply; slim "TOFIs" are at risk.

• Virtue, S. and Vidal-Puig, A. (2010) 'Adipose tissue expandability, lipotoxicity and the metabolic syndrome—an allostatic perspective', Biochimica et Biophysica Acta, 1801(3), pp. 338–349. doi:10.1016/j.bbalip.2009.12.006
• Taylor, R. and Holman, R.R. (2015) 'Normal weight individuals who develop type 2 diabetes: the personal fat threshold', Clinical Science, 128(7), pp. 405–410. doi:10.1042/CS20140553

South Asians tend towards limited fat storage capacity, which helps explain high type 2 diabetes and heart disease at lower BMI.

• Sniderman, A.D. et al. (2007) 'Why might South Asians be so susceptible to central obesity and its atherogenic consequences? The adipose tissue overflow hypothesis', International Journal of Epidemiology, 36(1), pp. 220–225. doi:10.1093/ije/dyl245

Rapid weight loss is not worse for long-term results.

• Purcell, K. et al. (2014) 'The effect of rate of weight loss on long-term weight management: a randomised controlled trial', Lancet Diabetes & Endocrinology, 2(12), pp. 954–962. doi:10.1016/S2213-8587(14)70200-1

Visceral fat is the first fat to go.

• Chaston, T.B. and Dixon, J.B. (2008) 'Factors associated with percent change in visceral versus subcutaneous abdominal fat during weight loss: findings from a systematic review', International Journal of Obesity, 32(4), pp. 619–628. doi:10.1038/sj.ijo.0803761

Just 1 kg of visceral fat quadruples a woman's risk of type 2 diabetes.

• Karlsson, T. et al. (2019) 'Contribution of genetics to visceral adiposity and its relation to cardiovascular and metabolic disease', Nature Medicine, 25(9), pp. 1390–1395. doi:10.1038/s41591-019-0563-7

Losing visceral fat quickly improves immunity and protects against Covid-19 cytokine storms.

• Watanabe, M. et al. (2020) 'Visceral fat shows the strongest association with the need of intensive care in patients with COVID-19', Metabolism, 111, 154319. doi:10.1016/j.metabol.2020.154319

"The nation that destroys its soil destroys itself" (Franklin D. Roosevelt).

• Roosevelt, F.D. (1937) Letter to all State Governors on a Uniform Soil Conservation Law, 26 February. The American Presidency Project. Available at: https://www.presidency.ucsb.edu/documents/letter-all-state-governors-uniform-soil-conservation-law

Allan Savory recommended culling elephants in 1960s Africa to stop land degradation, about 40,000 were shot, and the land got worse.

• Savory, A. (2013) How to fight desertification and reverse climate change [TED talk]. Summary: TED Blog (2013) 'Fighting the growing deserts, with livestock: Allan Savory at TED2013'. Available at: https://blog.ted.com/fighting-the-growing-deserts-with-livestock-allan-savory-at-ted2013/

A third of the world's land is at risk of desertification.

• United Nations Convention to Combat Desertification (n.d.) Desertification: overview. Available at: https://www.unccd.int/land-and-life/desertification/overview

Planned grazing by moving herds regenerates soil and captures CO₂.

• Hawkins, H.J. (2017) 'A global assessment of Holistic Planned Grazing™ compared with season-long, continuous grazing: meta-analysis findings', African Journal of Range & Forage Science, 34(2), pp. 65–75. doi:10.2989/10220119.2017.1358213
• Briske, D.D. et al. (2013) 'The Savory method can not green deserts or reverse climate change', Rangelands, 35(5), pp. 72–74. doi:10.2111/RANGELANDS-D-13-00044.1

Most of today's chronic diseases did not exist 120 years ago; sugar and seed oils are the root cause of insulin resistance and of nearly all modern illness.

• Thompson, R.C. et al. (2013) 'Atherosclerosis across 4000 years of human history: the Horus study of four ancient populations', Lancet, 381(9873), pp. 1211–1222. doi:10.1016/S0140-6736(13)60598-X

People with diabetes or high blood sugar are more prone to infections, including pneumonia.

• Critchley, J.A. et al. (2018) 'Glycemic control and risk of infections among people with type 1 or type 2 diabetes in a large primary care cohort study', Diabetes Care, 41(10), pp. 2127–2135. doi:10.2337/dc18-0287
• Williamson, E.J. et al. (2020) 'Factors associated with COVID-19-related death using OpenSAFELY', Nature, 584(7821), pp. 430–436. doi:10.1038/s41586-020-2521-4

Bacteria and other pathogens thrive on sugar.

• Critchley, J.A. et al. (2018) 'Glycemic control and risk of infections among people with type 1 or type 2 diabetes in a large primary care cohort study', Diabetes Care, 41(10), pp. 2127–2135. doi:10.2337/dc18-0287

Doctors receive only single-digit hours of nutrition training.

• Crowley, J., Ball, L. and Hiddink, G.J. (2019) 'Nutrition in medical education: a systematic review', Lancet Planetary Health, 3(9), pp. e379–e389. doi:10.1016/S2542-5196(19)30171-8

Weight loss is about insulin, not portion control.

• Hall, K.D. and Guo, J. (2017) 'Obesity energetics: body weight regulation and the effects of diet composition', Gastroenterology, 152(7), pp. 1718–1727.e3. doi:10.1053/j.gastro.2017.01.052
• Gardner, C.D. et al. (2018) 'Effect of low-fat vs low-carbohydrate diet on 12-month weight loss in overweight adults and the association with genotype pattern or insulin secretion: the DIETFITS randomized clinical trial', JAMA, 319(7), pp. 667–679. doi:10.1001/jama.2018.0245
• Ludwig, D.S. and Ebbeling, C.B. (2018) 'The carbohydrate-insulin model of obesity: beyond "calories in, calories out"', JAMA Internal Medicine, 178(8), pp. 1098–1103. doi:10.1001/jamainternmed.2018.2933

Seed oils build up toxicity in fat cells that takes years to clear.

• Hodson, L., Skeaff, C.M. and Fielding, B.A. (2008) 'Fatty acid composition of adipose tissue and blood in humans and its use as a biomarker of dietary intake', Progress in Lipid Research, 47(5), pp. 348–380. doi:10.1016/j.plipres.2008.03.003
• Dayton, S. et al. (1966) 'Composition of lipids in human serum and adipose tissue during prolonged feeding of a diet high in unsaturated fat', Journal of Lipid Research, 7(1), pp. 103–111. doi:10.1016/S0022-2275(20)39591-2

Olive and avocado oils are best served cold.

• de Alzaa, F., Guillaume, C. and Ravetti, L. (2021) 'Evaluation of chemical and nutritional changes in chips, chicken nuggets, and broccoli after deep-frying with extra virgin olive oil, canola, and grapeseed oils', Journal of Food Quality, 2021, 7319013. doi:10.1155/2021/7319013

Fruit eaten in its summer season comes with the vitamin D from sun that counters insulin resistance.

• Pittas, A.G. et al. (2019) 'Vitamin D supplementation and prevention of type 2 diabetes', New England Journal of Medicine, 381(6), pp. 520–530. doi:10.1056/NEJMoa1900906

A glass of orange juice can contain the fructose of about 4 oranges; eat fruit, don't drink it.

• NHS (n.d.) Sugar: the facts. Available at: https://www.nhs.uk/live-well/eat-well/food-types/how-does-sugar-in-our-diet-affect-our-health/

The triglyceride/HDL ratio is a useful marker (of insulin resistance).

• McLaughlin, T. et al. (2003) 'Use of metabolic markers to identify overweight individuals who are insulin resistant', Annals of Internal Medicine, 139(10), pp. 802–809. doi:10.7326/0003-4819-139-10-200311180-00007

LDL is "not bad"; don't worry about high LDL if you have quit sugar, seed oils and processed food.

• Ference, B.A. et al. (2017) 'Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel', European Heart Journal, 38(32), pp. 2459–2472. doi:10.1093/eurheartj/ehx144
• Cholesterol Treatment Trialists' (CTT) Collaboration (2010) 'Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170,000 participants in 26 randomised trials', Lancet, 376(9753), pp. 1670–1681. doi:10.1016/S0140-6736(10)61350-5

For exercise, "little and often" is best; build strength.

• Cruz-Jentoft, A.J. et al. (2019) 'Sarcopenia: revised European consensus on definition and diagnosis', Age and Ageing, 48(1), pp. 16–31. doi:10.1093/ageing/afy169
• Cermak, N.M. et al. (2012) 'Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysis', American Journal of Clinical Nutrition, 96(6), pp. 1454–1464. doi:10.3945/ajcn.112.037556

Keep carbohydrate between 20 and 100 g.

• Feinman, R.D. et al. (2015) 'Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base', Nutrition, 31(1), pp. 1–13. doi:10.1016/j.nut.2014.06.011

One bad night's sleep can significantly raise insulin.

• Donga, E. et al. (2010) 'A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects', Journal of Clinical Endocrinology & Metabolism, 95(6), pp. 2963–2968. doi:10.1210/jc.2009-2430

Avoid foods with more than 5 ingredients.

• Hall, K.D. et al. (2019) 'Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake', Cell Metabolism, 30(1), pp. 67–77.e3. doi:10.1016/j.cmet.2019.05.008

Vitamin D3 matters, especially in winter and for people with darker skin.

• Scientific Advisory Committee on Nutrition (2016) Vitamin D and Health. London: TSO. Available at: https://www.gov.uk/government/publications/sacn-vitamin-d-and-health-report
• NHS (n.d.) Vitamin D. Available at: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/

Muscle cramps often signal a need for magnesium.

• Garrison, S.R. et al. (2020) 'Magnesium for skeletal muscle cramps', Cochrane Database of Systematic Reviews, 9, CD009402. doi:10.1002/14651858.CD009402.pub3

Fibre is not essential.

• Institute of Medicine (2005) Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academies Press. doi:10.17226/10490
• Reynolds, A. et al. (2019) 'Carbohydrate quality and human health: a series of systematic reviews and meta-analyses', Lancet, 393(10170), pp. 434–445. doi:10.1016/S0140-6736(18)31809-9

BBC report of a Dorset woman who died aged 112 and loved cream and butter.

• BBC News (2020) 'Joan Hocquard: Oldest person in Britain dies aged 112', 25 October. Available at: https://www.bbc.co.uk/news/uk-england-dorset-54681140