What is the optimal diet for athletes? While I donβt believe there is one optimal diet for every person, I do think there are characteristics that all healthy diets share. Namely, theyβre ancestralβbased on the types of foods that our bodies evolved to thrive onβand they include a mix of nutrient-dense plant and animal foods.
A recent documentary called The Game Changers claims otherwise. The experts and celebrities featured in the film argue that a plant-based, vegan diet is optimal for athletes and that animal foods are harmful for athletic performance and overall health.
There are a lot of myths and misconceptions on this topic, so I wanted to take this opportunity to debunk some of the biggest claims made in The Game Changers. For a full breakdown of what this movie gets wrong, download my Show Notes, and listen to my appearance on The Joe Rogan Experience.
Download Chrisβ Show Notes
Iβve conducted extensive research on the real impact of a plant-based diet over an omnivorous, ancestral diet. Iβm sharing that research with you now in hopes that it helps clear up some of the misconceptions on vegan diets.
What Is The Game Changers?
The Game Changers is an agenda-driven film, not an objective analysis of an optimal diet for athletes. The purpose of this film is to advocate for a plant-based diet. It hasnβt been peer-reviewed, and it plays very fast and loose with the science. Itβs propaganda for veganism, pure and simple.Β
This is a very slick, well-done film, and it has the potential to mislead a lot of people. But itβs full of misleading statements, half-truths, flat-out falsehoods, flawed logic, and absurdities. I found problems with a number of claims made in the movie, including:
- The gorilla analogy
- The idea that peanut butter has as much protein as beef or eggs
- The gladiator diet
- The impact of protein on strength and health
- Where B12 comes from
These are examples of some very misleading and disingenuous uses of science. For instance, you would have to eat almost one-third of a cup of peanut butter to equal the protein in 3 oz of beef or three eggs; stories about gladiatorsβ diets ignore important details like the fact that they were being fed the cheapest possible slave diet and had a life expectancy of about two years; and it isnβt easy to consume the amount of amino acids you need for strength and muscle mass when youβre eating only plantsβunless you include ultra-processed protein powders in your diet.
Post-debate critiques:
- βDid James Wilks Get Anything Right Against Chris Kresser? Joe Rogan Debate Breakdown,β Food Lies, YouTube
- @ChrisMasterjohn Twitter Thread, Chris Masterjohn
For more:Β
- βWhat Is an Ancestral Diet and How Does It Help You?β Chris Kresser
- βRHR: Why the Optimal Human Diet Includes Animal Protein,β Chris Kresser
- βWhat Is the Optimal Human Diet?β Chris Kresser
- βWhy You Should Think Twice About Vegetarian and Vegan Diets,β Chris Kresser
- βB12 Deficiency: What Everyone (Especially Vegetarians) Should Know,β Chris Kresser
References and resources:
- The Game Changers film, GameChangersMovie.com
- βIngredion invests $140 million for plant-based proteins,β MarketWatch
- MUSE Kitchen, MUSE School
- Propaganda definition, Lexico
- βMeat and Nicotinamide: A Causal Role in Human Evolution, History, and Demographics,β International Journal of Tryptophan Research
- βThe Critical Role Played by Animal Source Foods in Human (Homo) Evolution,β The Journal of Nutrition
- βImpact of meat and Lower Palaeolithic food processing techniques on chewing in humans,β Nature
- βOrigins of the Human Predatory Pattern: The Transition to Large-Animal Exploitation by Early Hominins,β Current Anthropology
- βDid Cooked Tubers Spur the Evolution of Big Brains?β Science
- Gorilla, San Diego Zoo
- βPotential impact of the digestible indispensable amino acid score as a measure of protein quality on dietary regulations and health,β Nutrition Reviews
- βPSIII-21 Processing of food proteins of animal origin sometimes, but not always, increases values for Digestible Indispensable Amino Acid Scores,β Journal of Animal Science
- βDigestible indispensable amino acid scores of nine cooked cereal grains,β The British Journal of Nutrition
- SELF Nutrition Data, Nutritiondata.self.com
- FoodData Central: Fish, salmon, coho, wild, cooked, moist heat, USDA
- FoodData Central: Lettuce, iceberg (includes crisphead types), raw, USDA
- βThe Impact of Egg Nutrient Composition and Its Consumption on Cholesterol Homeostasis,β Cholesterol
- FoodData Central: Lettuce, iceberg (includes crisphead types), raw, USDA
- βMeeting the Vitamin A Requirement: The Efficacy and Importance of Ξ²-Carotene in Animal Species,β The Scientific World Journal
- FoodData Central: Oysters, raw, USDA
- βThe Gladiator Diet,β Archaeology
- βPhelpsβ Pig Secret: He’s Boy Gorge,β New York Post
- βUsain Bolt Ate 100 Chicken McNuggets a Day in Beijing and Somehow Won Three Gold Medals,β Time
- βBolt Is Worldβs FastestβBy a Mile,β The New York Times
- βNutritional considerations for vegetarian athletes,β Nutrition
- βRed meat consumption and mortality: results from 2 prospective cohort studies,β Archives of Internal Medicine
- βSystematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes,β BMJ Open Diabetes Research & Care
- Coprophagy, ScienceDirect
- βB12 in Plant Foods,β Vegan Health
- βVitamin B-12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians,β The American Journal of Clinical Nutrition
- βSerum concentrations of vitamin B12 and folate in British male omnivores, vegetarians, and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study,β The European Journal of Clinical Nutrition
- βHomocysteine and vitamins in cardiovascular disease,β Clinical Chemistry
- βVitamin B-12 and homocysteine status among vegetarians: a global perspective,β The American Journal of Clinical Nutrition
- βPlasma total homocysteine status of vegetarians compared with omnivores: a systematic review and meta-analysis,β The British Journal of Nutrition
- βVitamin B-12 and homocysteine status among vegetarians: a global perspective,β The American Journal of Clinical NutritionΒ
- βThe usefulness of holotranscobalamin in predicting vitamin B12 status in different clinical settings,β Current Drug MetabolismΒ
- βHow prevalent is vitamin B(12) deficiency among vegetarians?β Nutrition Reviews
Is a Vegan Diet Optimal for Athletic Performance?
One of the primary arguments made in The Game Changers is that a vegan diet is optimal for athletic performance. Experts in the film make a number of dubious claims in this area, including:
- Sacrificing carbohydrate calories for protein calories will lead to chronic fatigue and loss of stamina
- Vegetarian athletes get enough protein in their diets
- Eating too much protein is dangerous for your health
- Athletes can get enough essential amino acids solely from plant foods
- And many, many more
I encourage you to download my Show Notes for a full breakdown of each of these claims, but overall, itβs hard to imagine how athletes can get enough protein on a plant-based diet. Athletes in general need more protein than the recommended dietary allowance (RDA), and the amount they need will depend on the type of sport theyβre involved in, as well as their health status, age, sex, and more. While carbs are a great source of energy for explosive, glycolytic activities, in endurance sports, fat can be burned as the primary fuel source.
Protein quality matters just as much as quantity. Protein quality is a function of amino acid profile and bioavailability, and plant proteins are inferior to animal proteins on both counts. Animal proteins concentrate essential amino acids, so you get a lot more of them in a smaller amount of food (without having to rely on ultra-processed protein powders). Animal proteins have better bioavailability than plant proteins, meaning your body is better able to digest and absorb them. Whatβs more, plant proteins are missing a number of important nutrients athletes need, like vitamin B12, iron, creatine, calcium, and many, many more.
For more:
- βWhat Is an Ancestral Diet and How Does It Help You?β Chris Kresser
- Chart: Amino Acid Profile for Beef vs. Plant Proteins, Chris Kresser
- βB12 Deficiency: What Everyone (Especially Vegetarians) Should Know,β Chris Kresser
- βWhy You Should Think Twice about Taking Calcium Supplementsβ Chris Kresser
References and resources:
- βKeto-Adaptation and Endurance Exercise Capacity, Fatigue Recovery, and Exercise-Induced Muscle and Organ Damage Prevention: A Narrative Review,β Sports
- βAmerican Zach Bitter Crushes 100-Mile World Record With 6:48-Mile Pace,β Runnerβs World
- βBioconversion of dietary provitamin A carotenoids to vitamin A in humans,β The American Journal of Clinical Nutrition
- βMammalian carotenoid absorption and metabolism,β Pure and Applied Chemistry
- βVitamin A intake and hip fractures among postmenopausal women,β JAMA
- βNutrient profiles of vegetarian and nonvegetarian dietary patterns,β Journal of the Academy of Nutrition and Dietetics
- βEvidence that protein requirements have been significantly underestimated,β Current Opinion in Clinical Nutrition & Metabolic CareΒ
- βReevaluation of the protein requirement in young men with the indicator amino acid oxidation technique,β The American Journal of Clinical Nutrition
- βDietary Protein Requirement of Men >65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement,β The Journal of Nutrition
- βDietary protein requirement of female adults >65 years determined by the indicator amino acid oxidation technique is higher than current recommendations,β The Journal of Nutrition
- βHow much protein do you need per day?,β Examine.com
- FastStats: Overweight Prevalence, CDC
- βHomeostatic regulation of protein intake: in search of a mechanism,β The American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
- βDietary protein intake and renal function,β Nutrition & Metabolism
- βDo regular high protein diets have potential health risks on kidney function in athletes?,β International Journal of Sport Nutrition and Exercise MetabolismΒ
- βThe acid-base hypothesis: diet and bone in the Framingham Osteoporosis Study,β European Journal of Nutrition
- βProspective study of dietary protein intake and risk of hip fracture in postmenopausal women,β The American Journal of Clinical Nutrition
- βProtein consumption and bone mineral density in the elderly: the Rancho Bernardo Study,β American Journal of EpidemiologyΒ
- βBranched-chain amino acids and muscle protein synthesis in humans: myth or reality?β Journal of the International Society of Sports NutritionΒ
- FoodData Central: Beef, top sirloin, steak, separable lean only, trimmed to 1/8″ fat, choice, raw, USDA
- FoodData Central: Lentils, mature seeds, cooked, boiled, without salt, USDA
- FoodData Central: Chickpeas, dry, cooked, fat not added in cooking, USDA
- βIn Search For The Highest Quality Protein (And The Issues It Causes For Diet Guidelines),β Alex Fergus
- βEffect of creatine and weight training on muscle creatine and performance in vegetarians,β Medicine & Science in Sports & Exercise
- βNormal reference values for creatine, creatinine, and carnitine are lower in vegetarians,β Clinical Chemistry
- βEffect of creatine supplementation and a lacto-ovo-vegetarian diet on muscle creatine concentration,β International Journal of Sport Nutrition and Exercise Metabolism
- βVegan diets: practical advice for athletes and exercisers,β Journal of the International Society of Sports Nutrition
- βTaurine concentrations in the diet, plasma, urine and breast milk of vegans compared with omnivores,β British Journal of NutritionΒ
- βTaurine: a conditionally essential amino acid in humans? An overview in health and disease,β NutriciΓ³n Hospitalaria
- βPlasma concentrations and intakes of amino acids in male meat-eaters, fish-eaters, vegetarians and vegans: a cross-sectional analysis in the EPIC-Oxford cohort,β European Journal of Clinical Nutrition
- βVitamin B1, B2 and B6 status of vegetarians,β Journal of the Medical Association of Thailand
- βEffect of vegetarian diets on bone mineral density: a Bayesian meta-analysis,β The American Journal of Clinical Nutrition
- βEPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK,β Public Health Nutrition
- βNutrient intakes and eating behavior scores of vegetarian and nonvegetarian women,β Journal of the American Dietetic Association
- Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc, Institute of Medicine (US) Panel on Micronutrients
- βEffect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans,β Journal of the Science of Food and Agriculture
- βIs iron and zinc nutrition a concern for vegetarian infants and young children in industrialized countries?β The American Journal of Clinical Nutrition
- βDietary iron intake and iron status of German female vegans: results of the German vegan study,β Annals of Nutrition and MetabolismΒ
- βIron-deficiency anemia,β The New England Journal of Medicine
- βNutrient intake and iron status of Australian male vegetarians,β The European Journal of Clinical Nutrition
- βBioavailability of iron, zinc, and other trace minerals from vegetarian diets,β The American Journal of Clinical Nutrition
- βNutrient intake and haematological status of vegetarians and age-sex matched omnivores,β The European Journal of Clinical Nutrition
- βGrowth, development, and physical fitness of Flemish vegetarian children, adolescents, and young adults,β The American Journal of Clinical NutritionΒ
- βEffects of an omnivorous diet compared with a lactoovovegetarian diet on resistance-training-induced changes in body composition and skeletal muscle in older men,β The American Journal of Clinical Nutrition
- βMeat supplementation improves growth, cognitive, and behavioral outcomes in Kenyan children,β The Journal of Nutrition
- βPhysical fitness, anthropometric and metabolic parameters in vegetarian athletes,β The Journal of Sports Medicine and Physical FitnessΒ
- βA Comparison of a Vegetarian and Non-Vegetarian Diet in Indian Female Athletes in Relation to Exercise Performance,β Journal of Exercise Science and Physiotherapy
- Robert Oberst VS. Patrik Baboumian – What I eat in a Day, YouTube
- Β βVeganism, vegetarianism, bone mineral density, and fracture risk: a systematic review and meta-analysis,β Nutrition Reviews
What Are the Effects of a Vegan Diet on Athletic Performance?
The key question is not whether itβs possible for athletes to thrive on a vegan diet, but whether itβs likely. There are always outliers, but the exceptions donβt make the rule. Just because some of the athletes in The Game Changers excel on a vegan diet, that doesnβt mean that everyone will.
There are many non-dietary factors influence athletic performance, including genetics, epigenetics, stress, sleep, work ethic, talent, coaching, etc. These are significant. Whatβs more, many of the athletes featured didnβt start out on a vegan diet. They switched from a standard American diet to a whole-foods, non-processed vegan diet. But what might have happened if they switched to a βnutrivoreβ diet with plenty of nutrient-dense animal and plant foods? Would they have done better than they did on a vegan diet? Yes, this is plausible.
In fact, the common trajectory for vegan athletes involves a βhoneymoonβ period. Initially, their performance stays the same or may even improve for a short time. But after a while, you see a significant decline in performance and well-being. Iβve also seen this to be true with many of my patients at the California Center for Functional Medicine, some of whom are high-level athletes, and others who arenβt. I donβt think the athletes featured in The Game Changers are examples of the core argument of the movie, which is that a vegan/plant-based diet improves athletic performance (and animal protein harms it).
For more:
- βWhat Is Nutrient Density and Why Is It Important?β Chris Kresser
References and resources:
- βAchieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications,β The American Journal of Clinical NutritionΒ
- βLong-chain conversion of [13C]linoleic acid and alpha-linolenic acid in response to marked changes in their dietary intake in men,β Journal of Lipid Research
- βDHA status of vegetarians,β Prostaglandins, Leukotrienes & Essential Fatty Acids
- βBeta-carotene conversion to vitamin A decreases as the dietary dose increases in humans,β The Journal of Nutrition
- βThe challenge to reach nutritional adequacy for vitamin A: Ξ²-carotene bioavailability and conversion–evidence in humans,β The American Journal of Clinical Nutrition
- βEffects of beetroot juice supplementation on intermittent high-intensity exercise efforts,β Journal of the International Society of Sports NutritionΒ
- Patrik Baboumian, Wikipedia
- Morgan Mitchell Profile, World Athletics
- United States – Women’s 400 Meters Rankings, Athletic.net
- βCam Newton has likely played his last game for Panthers,β ESPN
- βHow Cam Newtonβs vegan diet may be hurting Panthers QBβs play and injury recovery,β The Charlotte ObserverΒ
- βOrlando Pride’s Alex Morgan Out for Remainder of NWSL Season With Knee Injury,β Sports Illustrated
- βDamian Lillard ends strict vegan diet,β The Undefeated
- βTexansβ Foster not afraid to cheat on vegan diet,β The Houston Chronicle
- βHey, Arian FosterβWhere’s the Beef? Going Vegan in the NFL,β Sports Illustrated
- βWhy RB David Johnson Lost a Scary Amount of Weight After Going Vegan,β STACK
- βThese 19 elite athletes are vegan β here’s what made them switch their diet,β Business Insider
- βNutritional Support for Exercise-Induced Injuries,β Sports Medicine
- βInternational Society of Sports Nutrition Position Stand: protein and exercise,β Journal of the International Society of Sports Nutrition
- βAnti-Inflammatory Effects and Joint Protection in Collagen-Induced Arthritis after Treatment with IQ-1S, a Selective c-Jun N-Terminal Kinase Inhibitor,β Journal of Pharmacology and Experimental Therapeutics
- β24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain,β Current Medical Research and Opinion
- βEffects of whey and fortified collagen hydrolysate protein supplements on nitrogen balance and body composition in older women,β Journal of the American Dietetic Association
- βLocalization of type I and III collagen and fibronectin production in injured gastrocnemius muscle,β Laboratory Investigation
- βHow nutrition and exercise maintain the human musculoskeletal mass,β Journal of Anatomy
- βAcute energy deprivation affects skeletal muscle protein synthesis and associated intracellular signaling proteins in physically active adults,β The Journal of Nutrition
- βReduced resting skeletal muscle protein synthesis is rescued by resistance exercise and protein ingestion following short-term energy deficit,β American Journal of Physiology-Endocrinology and Metabolism
Are Animal Proteins and Foods Harmful?
One of the key claims in the film is that animal products increase the risk of disease and shortened lifespan. But The Game Changers makes the same mistake that other films and even scientific studies that advocate plant-based studies make: ignoring the importance of food quality.Β
Eating a nutrient-dense, ancestral diet based on whole foods is not the same as eating an ultra-processed standard American diet. If an athlete was subsisting on a junk food diet of Popeyes and KFC, it makes sense that they may feel better on a higher quality diet that includes fresh fruits and vegetables in place of fried, processed, and refined foods.
Observational studies on the effects of animal protein suffer from a similar problem, which is known as the βhealthy-user bias.β People who engage in a behavior that is seen as βhealthyβ are more likely to engage in other behaviors that are also perceived as healthy, and vice versa. Red meat, for example, has been perceived as unhealthy for so long that people who eat more of it are also more likely to engage in unhealthy habits, like smoking, being physically inactive, and eating fewer fruits and vegetables. Confounding factors like the healthy-user bias influence research and are difficult to control.
Many observational studies look at diets completely out of contextβfocusing solely on nutrients, isolated food components, or biomarkers, without considering the overall quality of the diet. One of the inevitable results of doing this is that many observational studies end up comparing two groups of people that are not at all similar, and this casts doubt on the findings. This is how we get misleading claims that vegetarians and vegans live longer than omnivores, or red meat causes serious health conditions like cancer or cardiovascular disease, or that eating meat disrupts your gut microbiome.
For more:
- Why Eating Meat Is Good for You, Chris Kresser
- The Truth about Red Meat eBook, Chris Kresser
- βWhy You Should Be Skeptical of the Latest Nutrition Headlinesβ Part 1 and Part 2, Chris Kresser
- βDo Vegetarians and Vegans Live Longer Than Meat Eaters?β Chris Kresser
- βDo Your Kids Need to Eat Meat to Thrive?β Chris Kresser
References and resources:
- βHealth risk factors associated with meat, fruit and vegetable consumption in cohort studies: A comprehensive meta-analysis,β PLOS ONE
- βOn the Ideology of Nutritionism,β Gastronomica: The Journal of Critical Food Studies
- βEffect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion,β JAMA
- Healthy Food Choices – Canada’s Food Guide, Government of Canada
- βVegetarian diet and all-cause mortality: Evidence from a large population-based Australian cohort – the 45 and Up Study,β Preventative Medicine
- 2015-2020 Dietary Guidelines: Answers to Your Questions, ChooseMyPlate
- βEvidence from prospective cohort studies does not support current dietary fat guidelines: a systematic review and meta-analysis,β British Journal of Sports Medicine
- βEvidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis,β Open Heart
- βFat or fiction: the diet-heart hypothesis,β BMJ Evidence-Based Medicine
- βUnprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium,β Annals of Internal Medicine
- Redesigning the Process for Establishing the Dietary Guidelines for Americans, National Academies Press
- βOpinion: The latest flip-flop on red meat uses best science in place of best guesses,β Los Angeles Times
- βHass Avocado Modulates Postprandial Vascular Reactivity and Postprandial Inflammatory Responses To a Hamburger Meal In Healthy Volunteers,β Food & Function
- βMeta-analysis of prospective studies of red meat consumption and colorectal cancer,β European Journal of Cancer Prevention
- βProcessed and Unprocessed Red Meat and Risk of Colorectal Cancer: Analysis by Tumor Location and Modification by Time,β PLOS ONE
- βRed meat and colorectal cancer: a critical summary of prospective epidemiologic studies,β Obesity Reviews
- βRed and processed meat consumption and the risk of esophageal and gastric cancer subtypes in The Netherlands Cohort Study,β Annals of Oncology
- βMeat consumption and cancer risk: a case-control study in Uruguay,β Asian Pacific Journal of Cancer Prevention
- βFruits, vegetables and the risk of cancer: a multisite case-control study in Uruguay,β Asian Pacific Journal of Cancer Prevention
- βRed Meat and Colorectal Cancer: A Quantitative Update on the State of the Epidemiologic Science,β The Journal of the American College of Nutrition
- βHuman uptake and incorporation of an immunogenic nonhuman dietary sialic acid,β PNAS
- βCardiovascular disease in the masai,β Atherosclerosis
- βDaily energy expenditure and cardiovascular risk in Masai, rural and urban Bantu Tanzanians,β British Journal of Sports Medicine
- βHeme Iron from Meat and Risk of Colorectal Cancer: A Meta-analysis and a Review of the Mechanisms Involved,β Cancer Prevention Research
- βGreen vegetables, red meat and colon cancer: chlorophyll prevents the cytotoxic and hyperproliferative effects of haem in rat colon,β Carcinogenesis
- βHeme Iron Intake, Dietary Antioxidant Capacity, and Risk of Colorectal Adenomas in a Large Cohort Study of French Women,β Cancer Epidemiology, Biomarkers & Prevention
- βTotal antioxidant potential of fruit and vegetables and risk of gastric cancer,β Gastroenterology
- βDietary intake of heme iron and risk of cardiovascular disease: a dose-response meta-analysis of prospective cohort studies,β Nutrition, Metabolism and Cardiovascular Diseases
- βGut Microbe-Generated TMAO from Dietary Choline Is Prothrombotic in Subjects,β Circulation
- βEffect of egg ingestion on trimethylamine-N-oxide production in humans: a randomized, controlled, dose-response study,β The American Journal of Clinical Nutrition
- βDietary precursors of trimethylamine in man: a pilot study,β Food and Chemical Toxicology
- βIntestinal Microbial Metabolism of Phosphatidylcholine and Cardiovascular Risk,β The New England Journal of Medicine
- βIntestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis,β Nature Medicine
- βMetabolic, Epigenetic, and Transgenerational Effects of Gut Bacterial Choline Consumption,β Cell Host Microbe
- βBlood Trimethylamine-N-Oxide Originates from Microbiota Mediated Breakdown of Phosphatidylcholine and Absorption from Small Intestine,β PLOS ONE
- βA Paleolithic diet lowers resistant starch intake but does not affect serum trimethylamine-N-oxide concentrations in healthy women,β British Journal of Nutrition
- βPurification and comparison of liver microsomal flavin-containing monooxygenase from normal and streptozotocin-diabetic rats,β Biochemical Pharmacology
- Frequently Asked Questions about GFR Estimates, National Kidney Foundation
- Prediabetes: Your Chance to Prevent Type 2 Diabetes, CDC
- About Diabetes, CDC
- βEgg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies,β BMJ (Clinical Research Edition)
- βEgg consumption and CHD and stroke mortality: a prospective study of US adults,β Public Health Nutrition
- Β βIntake of animal products and stroke mortality in the Hiroshima/Nagasaki Life Span Study,β International Journal of Epidemiology
- βEffect of cruciferous vegetable consumption on heterocyclic aromatic amine metabolism in man,β Carcinogenesis
- βEffect of marinades on the formation of heterocyclic amines in grilled beef steaks,β Journal of Food Science
- βReduced Dietary Intake of Carbohydrates by Obese Subjects Results in Decreased Concentrations of Butyrate and Butyrate-Producing Bacteria in Feces,β Applied and Environmental Microbiology
- βHigh-protein, reduced-carbohydrate weight-loss diets promote metabolite profiles likely to be detrimental to colonic health,β The American Journal of Clinical Nutrition
- βGut microbiome response to a modern Paleolithic diet in a Western lifestyle context,β PLOS ONE
- βStarving our Microbial Self: The Deleterious Consequences of a Diet Deficient in Microbiota-Accessible Carbohydrates,β Cell Metabolism
- βDietary risk factors for colon cancer in a low-risk population,β American Journal of Epidemiology
- βPoultry and Fish Consumption in Relation to Total Cancer Mortality: A Meta-Analysis of Prospective Studies,β Nutrition and CancerΒ
- βDoes the American Cancer Society Promote Meat?β American Cancer Society
- βDairy product consumption and development of cancer: an overview of reviews,β BMJ Open
- βComprehensive Review of the Impact of Dairy Foods and Dairy Fat on Cardiometabolic Risk,β Advances in Nutrition
- βThe relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease,β European Journal of NutritionΒ
- βProduction-related contaminants (pesticides, antibiotics and hormones) in organic and conventionally produced milk samples sold in the USA,β Public Health Nutrition
- βDairy products and inflammation: A review of the clinical evidence,β Critical Reviews in Food Science and Nutrition
- βDecrease of postprandial endothelial dysfunction by spice mix added to high-fat hamburger meat in men with Type 2 diabetes mellitus,β Diabetic Medicine
- βAntioxidant-rich spice added to hamburger meat during cooking results in reduced meat, plasma, and urine malondialdehyde concentrations,β The American Journal of Clinical Nutrition
- βDietary proteins improve endothelial function under fasting conditions but not in the postprandial state, with no effects on markers of low-grade inflammation,β The British Journal of Nutrition
- βIncreased Lean Red Meat Intake Does Not Elevate Markers of Oxidative Stress and Inflammation in Humans,β The Journal of Nutrition
- βAn oily fish diet increases insulin sensitivity compared to a red meat diet in young iron-deficient women,β The British Journal of Nutrition
- βBeneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study,β Cardiovascular Diabetology
- βLong-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial,β The European Journal of Clinical Nutrition
- βRandomized controlled trials investigating the relationship between dietary pattern and high-sensitivity C-reactive protein: a systematic review,β Nutrition Reviews
- βEffects of a Paleolithic Diet on Cardiovascular Disease Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials,β Advances in Nutrition
- βPaleolithic and Mediterranean Diet Pattern Scores Are Inversely Associated with Biomarkers of Inflammation and Oxidative Balance in Adults,β The Journal of Nutrition
- βAttenuated Low-Grade Inflammation Following Long-Term Dietary Intervention in Postmenopausal Women with Obesity,β Obesity
- βEffects of dietary carbohydrate restriction versus low-fat diet on flow-mediated dilation,β Metabolism: Clinical and ExperimentalΒ
- βEffects of weight loss on a low-carbohydrate diet on flow-mediated dilatation, adhesion molecules and adiponectin,β The British Journal of Nutrition
- βAcute Hyperglycemia Impairs Vascular Function in Healthy and Cardiometabolic Diseased Subjects: Systematic Review and Meta-Analysis,β Arteriosclerosis, Thrombosis, and Vascular Biology
- βAdaptation of Ξ²-Cell and Endothelial Function to Carbohydrate Loading: Influence of Insulin Resistance,β Diabetes
- βMediterranean diet and erectile dysfunction: a current perspective,β Central European Journal of Urology
- βErectile Dysfunction Precedes Coronary Artery Endothelial Dysfunction in Rats Fed a High-Fat, High-Sucrose, Western Pattern Diet,β The Journal of Sexual Medicine
- βDietary flavonoid intake and incidence of erectile dysfunction,β The American Journal of Clinical Nutrition
- βAssociation Between Cardiovascular Health and Endothelial Function With Future Erectile Dysfunction: The Multi-Ethnic Study of Atherosclerosis,β American Journal of Hypertension
- βMenstrual differences due to vegetarian and nonvegetarian diets,β The American Journal of Clinical Nutrition
- βVegetarianism and menstrual cycle disturbances: is there an association?,β The American Journal of Clinical Nutrition
- βAssociation between vegetarian diet and menstrual problems in young women: a case presentation and brief review,β Journal of Pediatric and Adolescent Gynecology
- βDieting influences the menstrual cycle: vegetarian versus nonvegetarian diet,β Fertility and Sterility
- βFood intake diet and sperm characteristics in a blue zone: a Loma Linda Study,β European Journal of Obstetrics & Gynecology and Reproductive Biology
- βVeganβvegetarian diets in pregnancy: danger or panacea? A systematic narrative review,β BJOG
- βIs vegetarianism healthy for children?β Critical Reviews in Food Science and Nutrition
- βCharacterization of the receptor for transcobalamin II isolated from human placenta,β The Journal of Biological Chemistry
- βTransport and endogenous release of vitamin B12 in the dually perfused human placenta,β The Journal of PediatricsΒ
- βDeterminants of cobalamin status in newborns,β Pediatrics
- βIncreased urinary methylmalonic acid excretion in breast-fed infants of vegetarian mothers and identification of an acceptable dietary source of vitamin B-12,β The American Journal of Clinical Nutrition
- βVitamin B-12: low milk concentrations are related to low serum concentrations in vegetarian women and to methylmalonic aciduria in their infants,β The American Journal of Clinical Nutrition
- βIncreased risk of vitamin B-12 and iron deficiency in infants on macrobiotic diets,β The American Journal of Clinical Nutrition
- βMacrobiotic nutrition and child health: results of a population-based, mixed-longitudinal cohort study in The Netherlands,β The American Journal of Clinical Nutrition
- βMethylmalonic acid and homocysteine in plasma as indicators of functional cobalamin deficiency in infants on macrobiotic diets,β Pediatric Research
- βVitamin B-12 status in a macrobiotic community,β The American Journal of Clinical Nutrition
- βHigh prevalence of cobalamin deficiency in Guatemalan schoolchildren: associations with low plasma holotranscobalamin II and elevated serum methylmalonic acid and plasma homocysteine concentrations,β The American Journal of Clinical Nutrition
- βRisk of persistent cobalamin deficiency in adolescents fed a macrobiotic diet in early life,β The American Journal of Clinical Nutrition
- βRisk of persistent cobalamin deficiency in adolescents fed a macrobiotic diet in early life,β The American Journal of Clinical Nutrition
- βSigns of impaired cognitive function in adolescents with marginal cobalamin status,β The American Journal of Clinical Nutrition
- βLow bone mineral density and bone mineral content are associated with low cobalamin status in adolescents,β European Journal of NutritionΒ
- βA vitamin B-12 supplement of 500 ΞΌg/d for eight weeks does not normalize urinary methylmalonic acid or other biomarkers of vitamin B-12 status in elderly people with moderately poor vitamin B-12 status,β The Journal of Nutrition
- βCulled males, infant mortality and reproductive success in a pre-industrial Finnish population,β Proceedings of the Royal Society B
- βChanges in Income at Macro Level Predict Sex Ratio at Birth in OECD Countries,β PLOS ONE
- βVegetarian diets. Are they good for pregnant women and their babies?β The Practising Midwife
- βPersistence of neurological damage induced by dietary vitamin B-12 deficiency in infancy,β Archives of Disease in Childhood
- βSevere vitamin B12 deficiency in an exclusively breastfed 5-month-old Italian infant born to a mother receiving multivitamin supplementation during pregnancy,β BMC Pediatrics
- βDietary intake and nutritional status of vegetarian and omnivorous preschool children and their parents in Taiwan,β Nutrition Research
- βLong-chain n-3 PUFA in vegetarian women: a metabolic perspective,β Journal of Nutritional Science
Research on Animal Foods and Conflicts of Interest
Another claim made in the film is that recent research exonerating cholesterol, saturated fat, and red meat is tainted because itβs funded by the meat, egg, and dairy industry. Iβve long argued that corporate funding of medical research is a problem. But itβs not just by the meat, egg, and dairy industryβthe Big Food lobby that supports processed and refined foods like sugar and industrial seed oils is far larger. Historically, the sugar lobby paid for research in the 1960s with the goal of pointing the finger at fat, rather than sugar, as the primary driver of cardiovascular disease.
In fact, virtually all the medical experts in The Game Changers profit from selling books, supplements, or other products related to the vegan diet. Conflicts of interest go both ways, but the film doesnβt make any mention of this.
For more:
- βWhy You Should Be Skeptical of the Latest Nutrition Headlinesβ Part 1 and Part 2, Chris Kresser
References and resources:
- βSugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents,β JAMA Internal Medicine
- βFood Industry Funding of Nutrition Research: The Relevance of History for Current Debates,βΒ JAMA Internal Medicine
- βMy Debate with David Katz,β Nina Teicholz
Is Veganism the βNaturalβ Human Diet?
One of the most preposterous claims in The Game Changers is that Paleolithic humans ate mostly plants. This is literally rewriting history, and it goes against what virtually all respectable anthropologists believe. Our hominid ancestors have been eating meat for at least 2.5 million years. There is also wide agreement that going even further back in time, our primate ancestors likely ate a diet similar to that of modern chimps, which we now know eat vertebrates.
It is true that we canβt know with certainty the exact proportion of animal foods vs. plants that our Paleolithic ancestors ate. That said, the archeological record provides strong evidence that animal products played a critical role in human evolution. The fossil record clearly indicates a strong history of animal product consumption in humans from 130,000 to 13,000 years ago.
For more:
- βWhat Is an Ancestral Diet and How Does It Help You?β Chris Kresser
- βWhat Is the Optimal Human Diet?β Chris Kresser
References and resources:
- βEnvironment and behavior of 2.5-million-year-old Bouri hominids,β Science
- βStable isotope evidence of meat eating and hunting specialization in adult male chimpanzees,β PNAS
- The Story of the Human Body: Evolution, Health, and Disease, Daniel E. Lieberman
- βIsotopic biogeochemistry (13C,15N) of fossil vertebrate collagen: application to the study of a past food web including Neandertal man,β Journal of Human Evolution
- βEffect of diet, physiology and climate on carbon and nitrogen stable isotopes of collagen in a late pleistocene anthropic palaeoecosystem: Marillac, Charente, France,β Journal of Archaeological Science
- βPalaeoenvironmental and Palaeodietary Implications of Isotopic Biogeochemistry of Last Interglacial Neanderthal and Mammal Bones in Scladina Cave (Belgium),β Journal of Archaeological Science
- βStable isotopes and the seasonality of the Oronsay middens,β Antiquity
- βA brief review of the archaeological evidence for Palaeolithic and Neolithic subsistence,β The European Journal of Clinical Nutrition
- βNeanderthal diet at Vindija and Neanderthal predation: the evidence from stable isotopes,β PNAS
- βPlant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets,β The American Journal of Clinical Nutrition
- βThe paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic,β The European Journal of Clinical Nutrition
Will a Plant-Based Diet Save the World?
Several common, yet inaccurate, claims about the environmental impacts of animal foods are made in The Game Changers, like:
- Producing meat takes up too much farmland and cropland, and that livestock consume valuable food/calories that could be used to feed humans
- Livestock are responsible for a large percentage of greenhouse gas emissions
- Shifting to a plant-based diet would have a significant impact on greenhouse gas emissions and would free up land that could be used to grow crops
In reality, most of the land that is used to cultivate livestock is suitable only for grazing. It could not be used for crop production. And most livestock feed is not grown specifically for livestockβit is a byproduct of food overproduction processes. Eliminating livestock wouldnβt increase the food supply for humans.Β
When it comes to greenhouse gasses, the common statistics cited reflect the environmental impact of industrial beef production, not regenerative agriculture. While I do agree with plant-based diet advocates that our current concentrated animal feeding operation (CAFO) system for producing beef and other animal foods is problematic, where we disagree is on the solution. They propose eliminating animal foods from the diet; I propose regenerative agriculture that includes grass-fed meat.
Our soils are rapidly deteriorating due to erosion, nutrient depletion, and loss of organic carbon. We desperately need new methods of restoring healthy soil, and regenerative, holistically managed livestock is a time-tested and proven method. This means converting cropland used for livestock to grassland and allowing livestock to graze there. Grass-fed cattle can actually sequester carbon from the atmosphere, meaning they can be either net-carbon neutral or even act as a carbon sink.
For more:
References and resources:
- Articles and Infographics, Sacred Cow
- βLivestock on grazing lands,β Livestock and the Environment. Meeting the Challenge
- βChanges in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century,β The American Journal of Clinical Nutrition
- βOmega-6 and omega-3 oxylipins are implicated in soybean oil-induced obesity in mice,β Scientific Reports
- βLivestock: On our plates or eating at our table? A new analysis of the feed/food debate,β Global Food Security
- Sources of Greenhouse Gas Emissions, EPA
- βGrazing management that regenerates ecosystem function and grazingland livelihoods,β African Journal of Range & Forage Science
- βForages and Pastures Symposium: Cover Crops in Livestock Production: Whole-System Approach: Managing grazing to restore soil health and farm livelihoods,β Journal of Animal Science
- βNutritional and greenhouse gas impacts of removing animals from US agriculture,β PNAS
- βThe bioavailability of iron, zinc, protein and vitamin A is highly variable in French individual diets: Impact on nutrient inadequacy assessment and relation with the animal-to-plant ratio of diets,β Food Chemistry
- βThe Protein-Leverage Hypothesis: Do We Keep Eating Until We Get Enough Protein?β Darwinian Medicine
- βDo low-carbon-emission diets lead to higher nutritional quality and positive health outcomes? A systematic review of the literature,β Public Health Nutrition
- βCarbon Footprint Evaluation of Regenerative Grazing at White Oak Pastures: Results Presentation,β White Oak Pastures
- βResponse to FDA Questions- GRAS Notice 540 Soybean leghemoglobin- Impossible Foods, Inc.,β FDA
- βIs βFood-Techβ the Future of Food?β Medium
- βWhy Fake Burgers Make No Sense,β Sustainable Dish, Diana Rodgers, RD
- βField Deaths in Plant Agriculture,β Journal of Agricultural and Environmental Ethics
- βSoils are endangered, but the degradation can be rolled back,β Food and Agriculture Organization of the United Nations
- Science Library, Savory Institute
The Game Changers Debate with James Wilks
The Game Changers follows James Wilks, a combative instructor for the U.S. military and a former UFC fighter, as he converts to a vegan diet while sports stars, celebrities, doctors, and medical experts weigh in. They claim that a plant-based diet is optimal, especially for athletic performance, while animal products are harmful to health.
Even though it may be possible for some athletes to thrive on a plant-based diet, extensive research and my own clinical experience suggest that a vegan diet is not optimal for most people. The Game Changers relies on propaganda, sloppy or misleading science, and a lack of context to support its core argument, but I would like to set the record straight. Thatβs why I returned to the Joe Rogan Experience to debate James Wilks on this topic.
For more:
- βWhy Eating Meat Is Good for You,β Chris Kresser
- βWhy You Should Eat Meat: My Appearance on the Joe Rogan Experience,β Chris Kresser
- βWhat Is an Ancestral Diet and How Does It Help You?β Chris Kresser
- βWhat Is the Optimal Human Diet?β Chris Kresser
References and resources:
- βPlasma and blood viscosity in the prediction of cardiovascular disease and mortality in the Scottish Heart Health Extended Cohort Study,β European Journal of Preventative Cardiology
- βEffects of a Paleolithic Diet on Cardiovascular Disease Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials,β Advances in Nutrition
- βSystematic Review and Meta-Analysis of Clinical Trials of the Effects of Low Carbohydrate Diets on Cardiovascular Risk Factors,β Obesity Reviews
- βEffect of a Single High-Fat Meal on Endothelial Function in Healthy Subjects,β The American Journal of Cardiology
- βEffect of Antioxidant Vitamins on the Transient Impairment of Endothelium-Dependent Brachial Artery Vasoactivity Following a Single High-Fat Meal,β JAMA
- βThe Postprandial Appearance of Features of Cardiometabolic Risk: Acute Induction and Prevention by Nutrients and Other Dietary Substances,β Nutrients
- βEndothelial Dysfunction in Diabetes: The role of reparatory mechanisms,β Diabetes Care
- βLow-Fat Milk Ingestion Prevents Postprandial Hyperglycemia-Mediated Impairments in Vascular Endothelial Function in Obese Individuals with Metabolic Syndrome,β The Journal of Nutrition
- βMediterranean Dietary Pattern, Inflammation and Endothelial Function: A Systematic Review and Meta-Analysis of Intervention Trials,β Nutrition, Metabolism, and Cardiovascular Diseases
- βInfluence of food patterns on endothelial biomarkers: a systematic review,β The Journal of Clinical Hypertension
- βDietary proteins improve endothelial function under fasting conditions but not in the postprandial state, with no effects on markers of low-grade inflammation,β The British Journal of Nutrition
- βEndothelial dysfunction induced by postprandial lipemia is neutralized by addition of proteins to the fatty meal,β Atherosclerosis
- βMetabolic and Vascular Effect of the Mediterranean Diet,β International Journal of Molecular Sciences
- βAdvancing Beyond the βHeart-Healthy Dietβ for Peripheral Arterial Disease,β Journal of Vascular Surgery
- βEffect of carbohydrate restriction-induced weight loss on aortic pulse wave velocity in overweight men and women,β Applied Physiology Nutrition and Metabolism
- βPaleolithic and Mediterranean Diet Pattern Scores Are Inversely Associated with Biomarkers of Inflammation and Oxidative Balance in Adults,β The Journal of Nutrition
- βAttenuated Low-Grade Inflammation Following Long-Term Dietary Intervention in Postmenopausal Women with Obesity,β Obesity
- βDietary proteins improve endothelial function under fasting conditions but not in the postprandial state, with no effects on markers of low-grade inflammation,β The British Journal of Nutrition
- βIncreased Lean Red Meat Intake Does Not Elevate Markers of Oxidative Stress and Inflammation in Humans,β The Journal of Nutrition
- βAn oily fish diet increases insulin sensitivity compared to a red meat diet in young iron-deficient women,β The British Journal of Nutrition
- βShort-Term Mediterranean Diet Improves Endurance Exercise Performance: A Randomized-Sequence Crossover Trial,β Journal of the American College of Nutrition
- βKetogenic diet benefits body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes,β The Journal of the International Society of Sports NutritionΒ
- βThe Effects of a Ketogenic Diet on Exercise Metabolism and Physical Performance in Off-Road Cyclists,β Nutrients
- βEffects of a 12-Week Very-Low Carbohydrate High-Fat Diet on Maximal Aerobic Capacity, High-Intensity Intermittent Exercise, and Cardiac Autonomic Regulation: Non-randomized Parallel-Group Study,β Frontiers in Physiology
- βA Low-Carbohydrate Ketogenic Diet Reduces Body Mass Without Compromising Performance in Powerlifting and Olympic Weightlifting Athletes,β The Journal of Strength & Conditioning Research
- βThe Three-Month Effects of a Ketogenic Diet on Body Composition, Blood Parameters, and Performance Metrics in CrossFit Trainees: A Pilot Study,β Sports
- βEffects of a 4-Week Very Low-Carbohydrate Diet on High-Intensity Interval Training Responses,β Journal of Sports Science and Medicine
- βKill scientists, says animal rights chief,β The Guardian
- βAtkins Under Attack,β Newsweek
- β‘How Not to Die’ by Dr. Michael Greger: A Critical Review,β Healthline
- βSugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents,β JAMA Internal Medicine