Zoë has a PhD in public health nutrition. She struggles to find anything that is being taught in 'conventional' nutritional worlds that is true or evidence based. Hence why she spent 2008-10 writing The Obesity Epidemic - 135,000 words blowing apart: the misapplication of thermodynamics to dieting; the notion that 1lb = 3,500 calories, let alone that a deficit of 3,500 calories will lead to a weight loss of 1lb; the Seven Countries Study and the subsequent change in our diet advice, which has caused the obesity epidemic; the role of exercise in obesity and much more.
generated summary
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
- [01:24] Food Groups — https://www.zoeharcombe.com/2015/05/food-groups/
- [02:49] Plant based diet propaganda — https://www.zoeharcombe.com/2019/08/plant-based-diet-propaganda/
- [02:49] Plant based diet propaganda – Part 2 — https://www.zoeharcombe.com/2019/09/plant-based-diet-propaganda-part-2/
- [03:20] Vegetarian diets: what do we know of their effects on common chronic diseases? — https://doi.org/10.3945/ajcn.2009.26736K
- [05:50] The Levels of Evidence and Their Role in Evidence-Based Medicine — https://doi.org/10.1097/PRS.0b013e318219c171
- [06:09] Primary, Secondary, and Meta-Analysis of Research — https://doi.org/10.3102/0013189X005010003
- [06:53] PubMed search: vegan diet, meta-analysis filter — https://pubmed.ncbi.nlm.nih.gov/?term=vegan+diet&filter=pubt.meta-analysis&size=50
- [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
- [07:58] Veganism, vegetarianism, bone mineral density, and fracture risk: a systematic review and meta-analysis — https://doi.org/10.1093/nutrit/nuy045
- [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
- [09:45] Intensive Lifestyle Changes for Reversal of Coronary Heart Disease — https://doi.org/10.1001/jama.280.23.2001
- [10:53] The Game Changers — https://www.netflix.com/title/81157840
- [11:59] National Food Strategy – call for evidence — https://www.zoeharcombe.com/2019/10/national-food-strategy-call-for-evidence/
- [13:17] Food to help you live longer — https://www.zoeharcombe.com/2018/01/food-to-help-you-live-longer/
- [17:29] The Vegetarian Myth – Lierre Keith — https://www.zoeharcombe.com/2011/08/the-vegetarian-myth-lierre-keith/
- [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
- [19:18] Beef nutrition data used for the calorie calculation — https://nutritiondata.self.com/facts/beef-products/3669/2
- [19:42] Raw Whole Chicken nutrition data — https://www.nutritionix.com/food/raw-whole-chicken
- [20:05] Field Deaths in Plant Agriculture — https://doi.org/10.1007/s10806-018-9733-8
- [22:49] Thanet Earth — https://www.thanetearth.com/
- [25:34] Investigation of normal flatus production in healthy volunteers — https://doi.org/10.1136/gut.32.6.665
- [26:50] Climate Change Indicators: Atmospheric Concentrations of Greenhouse Gases — https://www.epa.gov/climate-indicators/climate-change-indicators-atmospheric-concentrations-greenhouse-gases
- [26:55] Methane Tracker 2020 — https://www.iea.org/reports/methane-tracker-2020
- [27:03] FAOSTAT Emissions Totals — https://www.fao.org/faostat/en/#data/GT/visualize
- [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
- [29:01] Food Reform for Sustainability and Health — https://eatforum.org/initiatives/fresh/
GPT-5.6 Thinking - high - 2026-07-12 - 2026-07-12
As a vegan I'm obviously biased from a moral standpoint, but I also found some of the given arguments kinda weak on some points, while others are true. I was mainly interested in going through the arguments for fun.
Nutritional argument/Game Changers part: This one I skipped mostly, as any argument that some particular kind of diet is more or less healthy depends on how the diet itself is structured and whether one takes it upon themselves to meet all the different macro- and micronutrients, be it with supplements or not. On B12, it's often supplemented into the feed of factory-farmed animals if I remember correctly, and EPA/DHA can be found in algae, as that's how fish get it in the first place.
Animal argument: There are 3 statements here: first, that if we all went vegan all the currently eaten animals like cows and pigs would vanish; second, that even a vegan diet uses so much land that it leads to the death of animals anyway; and third, that the mass production of meat is wrong and no one wants it. The first is true. There would be no cows, pigs or chickens, or at least not in their current numbers. But is this even bad? Most farm animals are overbred just to be better products, which leads to painful and miserable lives for them. So in my opinion, putting a stop to the artificial breeding of millions of them would be a worthwhile endeavor. In our current system, a good chunk of our land use goes to feed for farm animals, so living vegan would lead to a reduction in overall land use. The only true kernel here is that there is some land which isn't usable for growing crops but could be used for grazing animals or growing animal feed. But would this yield enough animal feed to sustain our current consumption? Nope. Which leads to the third point: if we want to consume as much meat as a society as we currently do, doing it in an industrial fashion is kinda the only realistic option, as free-roaming animals would need much more space.
The planet argument: These seem especially weak. First, natural vs. non-natural methane: obviously both are relevant, but stopping the methane from cows through a different diet is much simpler than attempting a worldwide extermination of termites, cockroaches, etc. And that it gets dismissed in climate reports is also pretty weird, since natural sources of methane are taken into account. The ppm part seems like straight-up pseudoscience: the amount in ppm isn't really a good indicator without taking into account the previous baseline, how strong it is in the context of the greenhouse effect (about 25x compared to CO2) and other factors. Cyanide kills someone in sub-gram territory, but we wouldn't say we didn't believe in its toxicity because of that.
Like, there are some interesting arguments to make or discussions to have, such as the use of land we can't grow crops on, or how to handle carnivorous animals we keep as pets, but most of the points given here are pretty undercomplex.
I disagree. Nutrient bio-availability means that it's not how a diet is "structured" but what you eat. There are things that we require for health as a species that we can only obtain from animal sources. Since you're vegan you have no choice but to supplement, but please keep in mind that nothing in this world exists on its own. Nutrients removed from the matrix of food our body expects to receive them from aren't the same.
Every species has evolved to eat specific things. We are meant to eat the meat and associated fat of animals, preferably ruminants and fish. No other animal on this planet "structures" its diet and supplements to "meet all the different macro and micronutrients." They eat the thing that they've evolved to eat when they're hungry, and stop eating it when they're not.
Humans are the only species intelligent enough to manufacture our own food, and dumb enough to actually eat it.
Thanks for looking at Zoe's lecture! Thats really nice of you! I appreciate it. I'll respond to some of your points inline below.
Fair enough, you do you! But if a diet is impossible to satisfy on natural whole foods, then the diet can't argue it is the most historically matched to human evolution.
She addresses this, but I'll recap - ruminants should just eat grass, not non-edible human crops, they are fed those crops because they are cheap and to fatten up the animal (while making it sick), which isn't great.
Technically yes, because the land used for ruminants isn't crop land.. but the current crop land would not yield more human food - animals are getting the waste products of that system, taking the animals out just leaves the waste.
I think you will find most zero carb carnivores more or less agree with you - the industrial farming system is barbaric and needs to change. Animals in their natural environments are the most ethical and healthy.
The core problem is the analysis of carbon emissions from animal sources makes huge assumptions, but more importantly doesn't look at the entire biocycle of a cow. A cow is not a net producer of carbon - it's inputs are just grass and water - any carbon it emits is coming from the grass and water. Looking at just the outputs of a cow's life it looks like a carbon polluter, but if you account for the inputs, its neutral, and if the cow is living in its natural habitat it's a carbon capture device. Cows eating grass cause the grass to sequester carbon in its root system, increasing soil health.
We can't isolate a single part of a single system in isolation and claim it's a bad thing, we have to look at the entire lifecycle.