Definitions and question

• Veganism excludes meat, fish, eggs, and dairy, leaving grains, legumes, nuts, seeds, vegetables, fruits, and plant oils.[1]
• Plant-based language is softer than vegan language, while some research definitions include people who occasionally eat meat or fish within vegetarian categories.[2][3][4]
• About 20 years as a vegetarian, including a vegan period, ended with rejection of the nutritional, animal, and planetary cases for veganism.

Nutrition and evidence

• Randomized trials, systematic reviews, and meta-analyses are at the top of the evidence hierarchy.[5][6]
• A PubMed search for vegan-diet meta-analyses produced 28 results, with three remaining after removal of mismatched designs, diets, and surrogate-marker analyses.[7]
• The mental-health meta-analysis linked vegetarian or vegan diets with higher depression risk and lower anxiety scores, which is not an endorsement of the diets.[8]
• The bone meta-analysis found lower femoral-neck and lumbar-spine bone mineral density in vegetarians and vegans, with higher fracture rates in vegans.[9]
• The type 2 diabetes meta-analysis found better glycemic control with low-carbohydrate, low-glycemic-index, Mediterranean, and high-protein diets, not vegetarian, vegan, or high-fiber diets.[10]
• The Ornish trial combined a low-fat vegetarian diet with smoking cessation, stress management, aerobic exercise, and psychosocial support, so its coronary improvement cannot be assigned to the diet.[11]
• The Game Changers erection experiment used three men over two nights, comparing a meat burrito with a plant burrito.[12]
• The Daily Dozen calculation supplied about 1,364 calories, nearly 70% carbohydrate, 16% fat, and 17% protein, with multiple vitamins, minerals, and animal-form nutrients absent or below the selected targets.[14]
• A healthy diet supplies essential nutrients without supplementation; a vegan diet requires supplementation and is therefore not healthy.[13][14]

Animals and food production

• Cattle, pigs, sheep, hens, and domestic cats would not exist in a vegan food system because livestock and carnivorous pets depend on animal agriculture.
• The Vegetarian Myth links crop production to unavoidable animal deaths: even protecting a lettuce requires excluding or killing slugs.[15]
• One cow was calculated to provide more than 600,000 calories and feed one person for a year, while the same calories would require about 228 chickens.[16][17][18]
• Fischer and Lamey's field-death paper is used with an estimate of seven billion animal deaths annually on harvested U.S. cropland, alongside about 40 million cattle and nine billion chickens killed for food.[19]
• Confining chickens and cattle in sheds or concrete systems is wrong, and removing grazing ruminants is also wrong because they belong on grassland.

Soil and climate

• Grazing ruminants host microflora, return material to the land, and rejuvenate topsoil; soil-free greenhouse production removes that relationship and requires added carbon dioxide.[20]
• Rotational systems such as Polyface Farm alternate animals, crops, and rest, while plant-only cultivation continually takes from soil without returning animal fertility.
• Local food comes from the surrounding land and water: cattle, sheep, dairy, fish, eggs, and seasonal vegetables, not distant imported produce.
• Humans also generate methane, including methane measured in flatus, so methane production is not unique to cattle.[21]
• Atmospheric methane is about 1.8 parts per million; the calculations reduce agriculture's share to about 0.44 and enteric fermentation to about 0.3 parts per million.[22][23][24]

Institutions and conclusion

• The EAT-Lancet diet permits zero animal food while allocating roughly 110 to 120 calories to table sugar.[25]
• FReSH includes agribusiness, chemical, technology, consultancy, processed-food, retail, pharmaceutical, insect-production, and other large corporate interests.[26]
• Veganism is rejected because removing livestock threatens topsoil and local food production, then transfers control of food to corporations whose incentive is commercial, not health.

References

1. [01:24] Food Groups — https://www.zoeharcombe.com/2015/05/food-groups/
2. [02:49] Plant based diet propaganda — https://www.zoeharcombe.com/2019/08/plant-based-diet-propaganda/
3. [02:49] Plant based diet propaganda – Part 2 — https://www.zoeharcombe.com/2019/09/plant-based-diet-propaganda-part-2/
4. [03:20] Vegetarian diets: what do we know of their effects on common chronic diseases? — https://doi.org/10.3945/ajcn.2009.26736K
5. [05:50] The Levels of Evidence and Their Role in Evidence-Based Medicine — https://doi.org/10.1097/PRS.0b013e318219c171
6. [06:09] Primary, Secondary, and Meta-Analysis of Research — https://doi.org/10.3102/0013189X005010003
7. [06:53] PubMed search: vegan diet, meta-analysis filter — https://pubmed.ncbi.nlm.nih.gov/?term=vegan+diet&filter=pubt.meta-analysis&size=50
8. [07:31] Vegetarianism and veganism compared with mental health and cognitive outcomes: a systematic review and meta-analysis — https://doi.org/10.1093/nutrit/nuaa030
9. [07:58] Veganism, vegetarianism, bone mineral density, and fracture risk: a systematic review and meta-analysis — https://doi.org/10.1093/nutrit/nuy045
10. [08:33] Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes — https://doi.org/10.3945/ajcn.112.042457
11. [09:45] Intensive Lifestyle Changes for Reversal of Coronary Heart Disease — https://doi.org/10.1001/jama.280.23.2001
12. [10:53] The Game Changers — https://www.netflix.com/title/81157840
13. [11:59] National Food Strategy – call for evidence — https://www.zoeharcombe.com/2019/10/national-food-strategy-call-for-evidence/
14. [13:17] Food to help you live longer — https://www.zoeharcombe.com/2018/01/food-to-help-you-live-longer/
15. [17:29] The Vegetarian Myth – Lierre Keith — https://www.zoeharcombe.com/2011/08/the-vegetarian-myth-lierre-keith/
16. [19:12] How Many Pounds of Meat Can We Expect From a Beef Animal? — https://beef.unl.edu/beefwatch/2020/how-many-pounds-meat-can-we-expect-beef-animal
17. [19:18] Beef nutrition data used for the calorie calculation — https://nutritiondata.self.com/facts/beef-products/3669/2
18. [19:42] Raw Whole Chicken nutrition data — https://www.nutritionix.com/food/raw-whole-chicken
19. [20:05] Field Deaths in Plant Agriculture — https://doi.org/10.1007/s10806-018-9733-8
20. [22:49] Thanet Earth — https://www.thanetearth.com/
21. [25:34] Investigation of normal flatus production in healthy volunteers — https://doi.org/10.1136/gut.32.6.665
22. [26:50] Climate Change Indicators: Atmospheric Concentrations of Greenhouse Gases — https://www.epa.gov/climate-indicators/climate-change-indicators-atmospheric-concentrations-greenhouse-gases
23. [26:55] Methane Tracker 2020 — https://www.iea.org/reports/methane-tracker-2020
24. [27:03] FAOSTAT Emissions Totals — https://www.fao.org/faostat/en/#data/GT/visualize
25. [28:42] Food in the Anthropocene: the EAT-Lancet Commission on healthy diets from sustainable food systems — https://doi.org/10.1016/S0140-6736(18)31788-4
26. [29:01] Food Reform for Sustainability and Health — https://eatforum.org/initiatives/fresh/

GPT-5.6 Thinking - high - 2026-07-12 - 2026-07-12