Thursday, September 12, 2019

The Sapien Diet: Peak Human or Food Lies?

I am a fan of Brian Sanders' podcast, Peak Human. I don't agree with much of his particular outlook on food and nutrition, but I do enjoy most of the guests that he interviews. It wasn't until recently that I gave his website a look. It was a bizarre experience to say the least. His site builds a case for something he calls the Sapien Diet. In addition to advocating for carbohydrate-restriction and time-restricted feeding, the diet is oddly focused on minimizing conditions that can negatively affect nutrient absorption and bioavailability. However, despite claiming that his perspective is evidence-based and non-biased, his personal biases toward food are quite transparent. I didn't have to look far.

This image is one such example, which implies that healthy foods like apples and bananas are both toxic and nutrient poor, or at least that they have diminished nutrient bioavailability.

While it is true that plant foods contain natural toxins like insect antifeedants, there is no clear evidence that nutritional doses of these toxins from whole foods pose a health risk to humans sufficient enough to justify specific food avoidance as a general recommendation. It is particularly odd to use this speculation to buttress something as pretentious as the "Sapien Diet", which he asserts is the optimal human diet. Profound claims require profound evidence. 

Using plant foods like bananas, apples, bell peppers, strawberries, and even butternut squash to demonstrate the dangers of anti-nutrients is very bizarre, as those plant foods are typically extremely low in anti-nutrients. Not only that, but edible plant ovaries like fruit contain some of the lowest concentrations of plant toxins specifically because they evolved to be eaten by animals like humans. Whereas foods like broccoli actually can contain high amounts of these toxins. However, on balance these plant toxins seem to exert a net positive effect on human health, not negative. The dangers of broccoli to human health are not clearly born out in any prospective, epidemiological, or experimental data. So it makes absolutely no sense to me to scare people away from plants, or suggest that general plant avoidance is supposedly a hallmark of the optimal human diet. It's antithetical to the vast majority of our evolutionary history.

Some of the only evidence cited for the acute dangers of anti-nutrients is a paper wherein a 65-year old woman drank nothing but smoothies containing an enormous amount of leafy green vegetables for ten days straight. The total oxalate content of the smoothie was 1.3g. This is 940% more oxalate than the average person consumes on a typical Western diet. This is not a nutritional dose. She used her blender to turn healthy leafy green vegetables into a drug that had a pharmacological effect on her body. Not only this, but this woman was also dosing relatively high amounts of calcium citrate (1200mg) and vitamin D (1000 IU). The authors of the paper also remark that it was likely the recent gastric bypass surgery she'd undergone in addition to a regimen of antibiotics she was taking at the time that predisposed her to the effect. The only common whole food on the market that has been shown to generate this effect all by itself is star fruit. One star fruit can contain up to 10g of oxalate. But that is the exception. Most fruit contains less than 10mg of oxalate.

Furthermore, it is implied on the opposite side of the infographic that butter is low in toxins with high nutrient bioavailability. It's ironic, considering that one of butter's primary nutrients, saturated fat, associates more consistently with poor health outcomes than broccoli, but I suppose that's a separate discussion. The point is, at the end of the day the health implications of butter are still largely up for legitimate academic debate. However, the health-promoting aspects of broccoli and even high-sugar fruit are exceedingly consistent and well supported by multiple lines of evidence. This alone suggests that there is more to a food than merely its micronutrient bioavailability. Lastly, while it is probably true that the bioavailability of nutrients in butter is probably higher than something like carrots, it is still the case that butter is one of the most nutrient-poor foods available on the market. It is hardly more nutritious than brown sugar when matched for calories. If I had to choose between butter or chocolate chip cookies as a means of furthering my nutrition, I'd be utterly foolish to choose the butter. I invite anyone to credibly challenge this statement.

It is also not always the case that animal foods are superior sources of nutrients. It is not even true that plant foods always have poorer bioavailability of nutrients when compared to animal foods. Calcium is a good example. The bioavailability of calcium from cruciferous vegetables is around fifty percent, whereas the bioavailability of calcium from either any sort of dairy product or even edible bones is typically around thirty percent. 

Sure, someone could point out that the absolute amount of calcium in the animal foods will be so high that they're still a better choice. Yes, I agree. However, I'll refer you back to my example between butter and carrots. It is true that the bioavailability of a nutrient like vitamin A will likely be higher with butter. It is also true you'll probably never get as much vitamin A from butter as you could get from carrots, despite the poorer bioavailability and the metabolic conversion inefficiencies. 

Moving on. The Sapien diet is essentially based on three basic principles. These principles are prefaced by the statement that the Sapien Diet is "how homo sapiens should eat". So, henceforth I will be rightly assuming that these are specific and unwavering rules for optimal nutrition for all human beings. Lofty claims, but that is essentially how it is stated. Let's begin.

The first principle encourages us to consume minimally processed, nutrient dense, whole foods. I actually agree with this recommendation, and see little to argue against in general. In the details we're encouraged to embrace a number of animal foods, which I also agree with. We're further encouraged to favour low-sugar fruit, though it is not explicitly stated why at this point. I strongly disagree with this recommendation for reasons I have stated above.

The last section of the blurb goes on to state that processed foods, sugar, refined grains, and vegetable oil should be utterly avoided. At this point, it is not explained why. We're merely expected to take for granted that these foods are valueless and best excluded from our diet. I simply don't agree with that.

It is puzzling that nuts and seeds are included in the list of foods we're encouraged to embrace. Yet, these are the exact foods that are typically highest in anti-nutrients, plant toxins, and the plant oils we're encouraged to avoid. These foods actually do associate more strongly with health problems than most other plant foods (especially fruit), as they are typically more allergenic and more strongly associated with mineral deficiency syndromes due to their high phytate content and their dense polyphenol content. I'm not saying they're bad foods. I'm merely pointing out an apparent inconsistency with regards to the Sapien Diet's priorities.

The second principle first encourages us to target protein, include protein with every meal, and make sure protein adequacy is met. I agree with this. It then states that we should favour animal protein over plant protein. I agree with this, too. It's a surer bet that you'll meet your protein requirements if you're favouring animal foods. However, some of us actually can't satisfy the second principle thus far without violating the first principle, even if we're sticking to animal protein. The elderly are a good example. It is prohibitively difficult for some elderly people to meet their protein requirements due to common decrements in appetite that tend to result from old age. Highly processed foods like whey protein isolate can step in to ensure these people get what they need. As trivial of an example as that may appear, it is nonetheless one level of nuance with far-reaching implications that can easily break the Sapien Diet's core heuristics. Not everyone can do what this diet is asking them to do, which again cuts against the notion that the Sapien Diet is how homo sapiens should eat.

It is then implied that we're to favour animal protein over plant protein on the basis that animal protein is more bioavailable. Again, I agree. However, this isn't ample justification for plant protein avoidance, if that is actually what is being suggested. A diet of steak and butter will have less protein and less overall nutrition than a diet of steak and, say, lentils when matched for calories. Why would we want to avoid the lentils in this case? Lentils can not only provide added protein, but they can also augment the overall nutritional profile of the diet. A better recommendation might be to simply target protein generally, and don't be afraid of your food.

As we continue reading, we'll see that he plays to a dubious yet bizarrely popular low-carb trope⁠— that fat is the preferred fuel of the body and provides unique health benefits, therefore carbohydrate-restriction is both advised and optimal. I wholeheartedly disagree. I'm not going to go into all of the reasons as to why right now, but perhaps we could further explore my disagreement if I were invited onto the Peak Human podcast to discuss them verbally. Carbohydrate-deprivation could have some unique benefits, but there is no clear evidence that these benefits aren't equally offset by decrements elsewhere. Everything has a cost. Not only that, but the notion that fat is the preferred fuel for the human body is completely at odds with what is gleamed by even the most cursory evaluation of human metabolism and physiology. The whole idea is dead-on-arrival. It doesn't make sense.

I also find it very strange that we're to be guided specifically away from plant foods like bananas because they "provide a ton of energy (empty calories) and not a lot of nutrients", but also guided toward foods like coconut oil. Coconut oil is one of the most calorie-dense, nutrient-devoid foods someone could consume. One extra large Ron Jeremy-sized banana has the same calories as a single tablespoon of coconut oil, and the banana's nutritional profile absolutely crushes the coconut oil. Hands down. No contest. No argument. I'm not saying bananas are awesome or that coconut oil is bad. I'm saying the Sapien Diet contains many internal contradictions that make it seem more than just a little silly.

The last principle is time-restricted feeding. I'm actually surprised at this, since there is virtually no large scale validation of this practice as an effective modality for, well, anything. Some studies suggest that compressing your feeding window merely shortens the amount of time you have to shove food in your face during the day, and thus can induce a caloric deficit in some people. I agree that if you're looking to lose body fat, this strategy can be effective for some people, but not all. It also has a tendency to hinder muscle hypertrophy in athletes when matched against time-unrestricted feeding, and probably isn't optimal as a general recommendation. I don't have much more to say than that. 

Here's my overall perspective and response to what I've read. I view all of nutrition essentially as a great big bin-packing problem. There are many satisfactory solutions to the problem that encourage health and meet our needs, spanning a huge array of different foods and food combinations. To me, the question isn't about which foods everyone should staunchly avoid or staunchly include in their diet, because that cancels many legitimate, safe opportunities for personalized nutrition. I just don't feel that this is the best way to pack the bin. The question should be about which foods best encourage optimal health for the individual, and on top of that which foods can be enjoyed without compromising that individual's optimal health. Maybe there are some core fundamental characteristics of the bin packing that should be conserved across all possible solutions. Things like achieving nutritional adequacy, staying in calorie balance, exercising, etc. But there is likely always room for flexibility that doesn't compromise the bin itself.

The blood-boiling thing that diet zealots just can't accept about this outlook is that it literally allows for the inclusion of all foods. Even junk foods. Is there some amount of liver or egg consumption that directly promotes optimal health? For most people I think the answer would probably be yes. Most people would probably be better off consuming some amount of liver or eggs as opposed to consuming none. However, is there some amount of banana that is compatible with optimal health? For the vast majority of people, absolutely! Banana is a healthy food. Furthermore, 
is there some amount of chocolate cake that is also compatible with optimal health? For most people who would be consuming it against the background of a diet that already maximally satisfies their personal nutritional needs, the answer would probably be yes as well.

Say you're going on a trip and you're packing a suitcase. Chances are good that regardless of the nature of your trip you will fill your suitcase with a core assortment of indispensable items. But then, you will likely have at least some leeway to customize and personalize much of whatever else it is that you will take with you. I look at nutrition the same way. Once the fundamentals have been optimally satisfied, you have at least some liberty to enjoy yourself and enjoy your foods. For one person, they might fill their extra suitcase space with bananas and mangoes. Others might fill that space with avocados and almonds. If either of them can pack a cookie or two without perturbing the essentials, I think that is perfectly fine and can possibly even be health-promoting in and of itself.

This is a typical example of my diet:

My diet breaks down to around 55% carbs, 15% fat, and 30% protein. At this moment I consume just shy of 2300 kcal per day. I can achieve nutritional adequacy of all essential vitamins, minerals, and amino acids within the first 1500 kcal of my day. If I wanted to fill the remainder with sugary fruit, starchy plants, and refined grains, what does their relative nutrient bioavailability or sugar content matter? Are there better options? Perhaps marginally for some of those things, sure. Would it make an appreciable difference? I doubt it. I enjoy my nutrient dense diet, and I enjoy the flexibility that it grants me. I'm granted the liberty to indulge more frequently by virtue of the fact that my overall dietary pattern is profoundly nutrient dense. That is part of the advantage of a nutrient dense diet, and the indulgences need not be a detraction.

We shouldn't devalue entire foods based on one context-sensitive aspect of those foods. No matter how tempted we are to do so. Be it phytate, toxins, lectins, processed food, carbohydrates, bioavailability, etc. All foods have value. If they didn't have value, people wouldn't eat them. Likely there is a place for nearly all foods in a healthy diet. 
Food avoidance may be a powerful heuristic that some people can use to lose weight and keep it off. For others, not so much. Some people would likely prefer moderation, however moderation might lead some other people directly to ruin. But I don't think either heuristic reigns supreme as a default approach. Nutrition is personal. I'm not persuaded that the Sapien Diet is the diet that all homo sapiens should be eating.

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