• William Shewfelt

Thoughts on a Nutritarian Diet vs Carnivore Diet

Quick note: This essay is presenting my layman's thoughts around Dr. Joel Fuhrman’s recent appearance on Mark Bell’s podcast. This essay is not authoritative. I’m simply sharing the questions I posed to myself while listening. I’m not a professional, I'm someone who’s trying to figure this stuff out. Part of the reason I was unconvinced by Dr. Fuhrman’s arguments is that I simply need more information at this point before making conclusive statements. I need the whole picture. Also, I have huge respect and admiration for Dr. Fuhrman and the body of work he has contributed.

I recently listened to an episode of Mark Bell’s Power Project podcast featuring Dr. Joel Fuhrman. For a little background, Mark Bell is a world champion powerlifter and all around badass. One of the things I love about his podcast is the incredible variety of high level guests as well as the thoughtful discussions that happen. Dr. Joel Fuhrman is a well-known doctor in the plant-based community. Famous for writing Eat to Live, he promotes an evidence-based nutritarian diet and lifestyle.

From my four years following a whole foods, plant based diet—I was definitely familiar with Fuhrman’s work (although my personal hero at the time was Dr. Michael Greger).

His podcast appearance on the Power Project raised many interesting points and I was forced to carefully analyze why I believe eating an animal-based diet is superior.

Here are a few points he raised as well as my thoughts and commentary.

Ultimately, the evidence seems to overwhelmingly support a plant-based diet in terms of long term health and longevity.

There are so many variables to consider. What evidence? Funded by who? What are the particulars of each and every study? Were they epidemiological? Was animal protein consumption separated from healthy user bias, processed meat, carbohydrate consumption, vegetable oil consumption, refined carbs, etc?

How many meals a day were these people eating? Did they exercise?

I get sent a lot of studies from people concerned about my health on a meat-based, carnivore diet. And I totally understand it. Yes—this diet seems ludicrous at this stage of scientific understanding. But I always regard new, alarming headlines like “Keto crotch!” Or “Carnivore Fad Diet Leads to Heart Disease” with a big, healthy dose of skepticism because there are simply a million variables that most people never consider.

Even with high quality studies, there are so many confounding factors and often times the authors of the studies lead with their bias—very quick to suggest potential causation to whatever supports their belief system (see: confirmation bias).

So yes…there’s an overwhelming amount of science that SEEMS to support a plant-based diet and disparage a high animal protein diet. But—I always consider healthy user bias, overall caloric load, food quality, micronutrients/nutrient density, eating frequency, the role of exercise and a million other things. It’s very difficult for me to take the current scientific consensus on nutrition at face value because it simply isn’t a settled debate. When you analyze the roots of the argument, it’s not always as solid as it seems.

A meat based diet is completely lacking in nutrient density and simply provides empty calories.

In fact, Fuhrman compared a steak to a bagel at one point in the discussion—citing both as sources of empty calories. Why would a steak be empty calories according to Fuhrman? Because it lacks antioxidants, phytochemicals (plant chemicals) and fails to significantly contribute to our RDAs.

I’m uncertain of the benefits of plant antioxidants. Some carnivore proponents like Dr. Paul Saladino have presented evidence that exogenous antioxidants may do absolutely nothing for us. He also uses the analogy of operating systems, saying that plants are a completely different operating system than animals—which may contribute to poor absorption of plant nutrients.

I think plant antioxidants may have a potential hormetic benefit, but it may possibly be offset by the nutrient inhibiting toxins and anti nutrients in the plant.

I also know that our own endogenous antioxidant glutathione can be upregulated through hormetic stressors like exercise, stress, etc. So it makes me wonder if we really need an additional stressor/stimulus for this.

The point is: I’m not sure antioxidant scores in plants are an effective method of ranking a food’s nutrient density because I’m not sure exogenous antioxidants are really that valuable.

The other criteria of nutrient density I heard Fuhrman present was micronutrients in the form of vitamins, minerals, and phytochemicals. It’s clear that glucose vs fat metabolism lead to different nutrient requirements in the body. This is why carnivores don’t tend to get scurvy. So maybe on carnivore the RDA’s would need to be adjusted? I’m also uncertain that phytochemicals are necessarily phytonutrients.

Too Much mTOR and IGF-1

This was an interesting one. Basically animal protein consumption “overshoots” optimal physiological levels of growth hormones and is simply too anabolic—potentially leading to not only excess muscle growth but also cancer cell proliferation. So everything is growing—the good and the bad.

But in what context? If you’re implementing fasting to down-regulate these hormones occasionally, would that perhaps create a better, more pulsatile environment in the body where there is increased autophagy? Balancing catabolism with anabolism? (not to be confused with cannibalism…)

Also, in the evidence referenced by Fuhrman—what was the food environment of those who experienced more cancer or heart disease with higher animal protein? Were they also consuming sugar, vegetable oils, refined carbohydrates? How many meals a day were they eating? Could the anabolic effects of animal protein simply exacerbated a cancerous growth that was caused by something else entirely (like a standard American diet? Sleep deprivation? Stress? Environmental toxins?)

I’m unconvinced that the anabolic effects of meat are necessarily cancer causing. They may potentially be cancer promoting in an environment of a hypercaloric diet and frequent consumption (especially of poor quality meat).

My Takeaway

Dr. Fuhrman is awesome and I highly respect him. He's doing amazing work which is really all that matters. I do however question his definition of nutrient density and I also question the science behind his major premises because I simply think there are far too many variables not being considered that could lead to completely different conclusions.

Eating a ton of poor quality meat for 5+ meals a day and snacks, with no exercise, poor sleep, cooked in vegetable oils, with table salt…is COMPLETELY different than a diet consisting of 1-2 meals a day, fasted exercise (incorporating resistance and cardio training), including the highest quality animal protein with minimal energy load (grassfed meats, pastured eggs, organ meats like liver, and wild caught seafood like salmon, sardines, oysters, mussels), and high quality sleep along with a low stress lifestyle.

TLDR? I’m going to continue practicing a carnivore diet and lifestyle in the healthiest, most optimal manner I can while I continue to have an open mind around the potential effects of plants and meat. Why? Because it's dramatically increased my quality of life and subjective experience of health. Hopefully by the time I’m 40…I’ll have it all figured out.

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