Yes, I am a fan of well-sourced meat. No, this is not a vegetarian bashing exercise.

There have a been a number of recent articles showcasing vegetarian/vegan dieters returning to meat. The reasons vary, but all line up with my approach to Eating For Health.
The stories
Here are the stories I caught recently:
- VIRPI MIKKONEN admits ‘My vegan diet ruined my health and brought on early menopause’
- Mother-of-two ditches vegan diet she followed for 15 YEARS and now she ONLY eats meat
- Going Back to Meat After Eating Vegan Made Anne Hathaway Feel ‘Like a Computer Rebooting’
- The Vegetarians Who Turned Into Butchers
The commonality: they adopted a lifestyle, followed diligently, but later abandoned. Once returning to meat these reports indicate the results are positive.
The vegetarian/vegan choice restricts variability in food consumption. A decrease in the variability of foods for an extended period is not ideal in my experience – this is NOT just advice for the vegetarian group.
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The Psychology Behind Why
An interesting article from 2014 in Psychology Today reported on a Humane Research Council Study looking at why vegetarians/vegans went down their path.
Here are a few highlights:
- 5 out of 6 people abandoned vegetarianism
- Twice as many vegetarians/vegans were politically liberal vs conservative
- Vegetarian/vegan more likely to be women
- Reasons cited were: taste, concern for animals, feelings of disgust, social justice, and religious beliefs.
- 37% of abandoners claim an interest in trying meat-free again
- 43% said it was too difficult to follow
An intriguing set of findings here. To me, I see identity or label attachment taking part as a key driver in adopting veganism/vegetarianism—not unlike that of someone who is keto or gluten-free. Let’s look at how this label adoption interacts with biology.
What Gets Missed In The Vegetarians/Vegans Diet
While not a complete list, these are the top deficiencies vegetarians a prone to:
Vitamin B12
Vitamin B12 is important, but it is most readily found in animal products. Yes, it is available elsewhere, but the likelihood remains that a deficiency will occur.
Alcohol can interfere with B12 metabolism, so those who have experienced a hangover have experienced some low B12 consequences.
Another concern here is that the cheapest B12 supplement, cyanocobalamin, is not the same as the biologically active methylcobalamin. There are other active forms of B12, but if you read a label with cyanocobalamin, I would advise to put that one down and look elsewhere.
Vitamin A
The plant form of vitamin A (beta carotene) must undergo conversion to the animal form (retinol) to be utilized by our bodies. Certain genes that code for enzymes are responsible for this conversion. One of the more common mutations I see when analyzing people’s genetics (from 23andme/Ancestry) is at this level. The effect is less conversion, so less Vitamin A in the proper form. If you are getting 100% of your Vitamin A intake from plants, and have this common genetic variant, you are at high risk for deficiency.
Other Fat Soluble Vitamins
Vitamins A, D, E, K comprise this group. Vitamin D and K2 specifically are best sourced from non-industrial animals. Everyone knows the importance of D, but K2 has an important role in calcium distribution throughout the body. The same issue described above with Vitamin A can impact D and K2 – they need conversion from plant to animal versions, which is susceptible to rate-limitations.
Omega 3 Fatty Acids
Omega 3’s are one from the group of essential fatty acids – essential because we cannot synthesize internally, so we must eat them. ALA is the form found in plants, but EPA and DHA are what our bodies (and brains especially) need. ALA does not get converted efficiently at all. Algae-based supplements that have DHA/EPA are where some vegetarians turn, but those that don’t are likely in an omega-3 deficient status – the brain is most impacted here.
Amino Acids
We build proteins from amino acids. We break proteins down during digestion (with sufficient acidity – see my whitepaper on the topic) into amino acids for absorption and use internally. The amino acid profiles of plants are less complete than animals 1. While this does not mean you can’t get enough amino acids from plants, it is more difficult. This might be in play for a major league baseball pitcher – athletes need sufficient sources of complete amino acid profiles:


Context
Does this mean we should tell everyone to switch to the carnivore label? Although I have seen excellent results reported in this scenario, I do not recommend these extremes. Long-term vegan/vegetarian is challenging to pull off and maintain a healthy status. Going all meat? You can miss some fibers and other vitamins/mineral profiles vegetables offer. Same for the keto/carb debate. Periods of both can be beneficial – identifying in one camp for a long time can be problematic. The reason keto helps so many is that our default state as a population is high carbohydrate. My recommendation to a keto enthusiast is to work in carbs periodically at least – a refeed day. The true superpower is metabolic flexibility.
I would extend the same logic to vegetarians – work back in meat/animal at least periodically. Our bodies thrive in multiple states and multiple sources of food. Locking into one has downsides. Adopting one state, in this case, vegetarian, for whatever reason brings in biological challenges that may not be necessary. Look specifically at the NY Times article about the butchers above. They featured people ethically opposed to industrial meat production, but once they found ethically sourced meat, things changed.
The commonality of why people who go vegan, keto, or carnivore experience an improvement in health is because of the avoidances from processed food – see these avoidances here.
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What If We Account For These Deficiencies
Is it possible to fix all the problems with discarding all animal sources? I wouldn’t recommend it, but there are others who appear to be having success.
Danielle Belardo is a current Cardiology Fellow, and present on social media (VeggieMD), who has adopted veganism. She is young and looks very healthy. But, many of the people in the stories above likely enjoyed the lifestyle for a while.

Carrie Diulus is a spine surgeon who is a type 1 diabetic on plant-based keto. She works diligently to keep insulin down and appears to have success. Avoiding high, prolonged insulin levels is key for diabetics and everyone else – read my paper why here.
These are smart, accomplished MD’s who have had a positive clinical impact on their patients. They are likely taking precautions to ensure the deficiencies above don’t occur. Might they still both benefit from periodic animal product intake? I think so, and further can’t think of any potential harm. Regardless, if you really want to commit to extended vegan periods, I would follow people experienced like these two – there are too many potential pitfalls to jump in blindly.
Variance is the Key
From stress to sunlight to animal products, I put forth that our biology is set up to thrive in the state of variability. Can excessive sun cause problems? Yep, but avoiding it entirely can cause potentially as many problems – see my paper on this topic here.
I approach diet the same way. First, know what toxins to avoid all the time. Then, incorporate when to eat – periods of fasting is key (and a variance!). Then build out a dietary strategy around variance as well. Change around macronutrient (protein/fat/carb) periodically and strategically. I have seen this variance bring higher levels of performance and health in myself and others. I put together these concepts in a detailed whitepaper, Why When To Eat Matters. Please have a look and reach out if I can be of any assistance.
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