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Experiments in Nutrition

In my last post I talked about watching some random lectures on classics, and the other day I watched this one called Diet as Medicine. Honestly, I didn’t find it that interesting, and I didn’t get much out of it, but it’s an anchor for me to collect some thoughts about nutrition that I’ve had over the last… two years or so? Prior to then, I had really no thoughts about nutrition at all, and my philosophy on the subject was an interesting patchwork of ideologies. The only thing I believed in was that protein is good, and I should eat more protein, which is about typical for an American. This is despite the fact that I’ve been vegan for six years, and for most people veganism is all about health. I truly just never thought about it that way.

Nutrition Science is Nonsense… or is it?

One reason I never thought about it is that I am a numbers guy, trained in the hard sciences (I’m also trained in the humanities, but forget about that), and nutrition science has a bad reputation. You think of tabloids, which tell you one week that wine is good and the next that wine is bad. So nutrition is a bunk science, right? Why even bother?

Well, that’s not exactly true. Believing that an entire field of science is nonsense is, of course, quite arrogant, and it turns out that tons of incredibly intelligent people have been thinking about the subject for as long as humans have been around. Pretty much everyone has an opinion on nutrition, because we all eat every day, and it’s the main way in which we interact with the outside world. But, reassuringly enough, the body of evidence in modern science (and some knowledge that has no place yet in the current paradigm — think all the new talk about “the gut microbiome” lately, or even “mitochondrial function”, which I think will be the next obsession of pop science) mostly points in the same direction. It turns out that if you ignore influencers (which is where we get most of our nutrition information) and instead look at scientific literature and cultural wisdom (the latter taken with a grain of salt, but just as we can’t be so arrogant to dismiss an entire field of science, it’s also a good idea to assume that smart people existed throughout human history), it pretty much converges on Michael Pollan’s famous maxim:

The (real) food here entails “whole” foods, or unprocessed ones. There are a few corollaries of these central axioms, as it were, that I believe in:

Mostly, I just try to eat enough (but not too much) and a wide variety of plant foods — this is something many cultures have settled on for centuries, and it’d be pretty silly to discard it and try to reinvent the wheel. I think pretty much any fruit or vegetable is healthy in this context, but I especially aim to include:

I also limit alcohol (actually, I may be a teetotaler now?), table sugar, and oil.

But within these parameters, there is so much that is interesting about nutrition as a science that I find fascinating. Mathematician and programmer Jeremy Kun nerdily put it this way: healthy eating is a linear programming problem. What that means is it’s a bit like packing furniture into a moving truck. You have to make sure you pack a bit of everything you need, but there’s more or less a fixed amount of space. What happens when you substitute beef for chickpeas? Cashews for olive oil? Zooming in further, protein is about the building blocks that are amino acids. Fat is about fatty acids. And plants have a staggering amount of components beyond vitamins and minerals (which were only fully mapped less than a century ago, by the way — so assuming that these elements are the limits of nutrition is almost as naive as the four humors).

Anyway, nothing about this is particularly controversial. It’s actually pretty boring. But some of my friends are eager to pick fights because I eschew a couple of things:

I would say something about how I don’t think much of carnivore or keto diets, but it turns out that despite their popularity they have never been considered seriously in the scientific literature apart from some admittedly interesting cases (keto developed as a treatment for epilepsy, for example), so why bother.

Experiments

I’ve been tinkering along with some personal experiments with the parameters above. I have a stubborn ten or so pounds to lose (don’t we all?) and I’ve been using it as a vehicle to test the boundaries with my own body.

For one, I tried lowering protein until I felt effects, and indeed it was right around the RDA (50-60g per day in total) that I started to lose strength and recovery. That’s pretty reasonable! In my vegan lifting days I used to aim for 150g, and when I was omnivorous it was closer to 200g (!) which is, quite frankly, absurd. Remember how nutrition is like packing furniture? When you eat that much protein, there’s little room for anything else, which is why *95% of Americans* don’t get enough fiber. It makes sense, because high-protein foods generally lack fiber (legumes are sort of an exception, which is why I prioritize them). These days, I’m thinking 70 - 80g is a good compromise. There are studies showing there are no benefits to additional protein even among high-level athletes (which I am not) beyond 1.6g/kg, and I think it’s even less for me, a regular guy who goes months without lifting weights.

The second type of experiment I tried involves the balance of carbs and fats, neither of which are inherently "bad", of course.

At the beginning, my diet was around 40% fat (from nuts and seeds, avocados, soy, olive oil). This is actually pretty close to the famous Mediterranean diet, which has been extensively studied, if a bit higher in fat. I leaned towards this because many of my favorite foods are high in fat. It ended up getting my cholesterol super low, which is nice, but I felt like something was missing and I often felt hungry. It actually felt closer to keto, which is an experiment I did in my youth (to successfully lose a bunch of weight that, of course, I eventually regained -- and that's why I don't do keto).

I’ve also tried the complete opposite, closer to the Okinawa diet, which was a bit too far. One of the longest-lived populations in the world survived on 85% carbs, mostly from Japanese sweet potatoes (which I’ve ended up adopting into my regular diet, but just because they’re delicious). In this paradigm, I cut fat and protein as low as possible to see what happened. I had a bit more energy than before, but something was missing again, and I was eating even when I wasn’t hungry.

I think something in the middle (closer to the Ethiopian runner’s diet, or what ultra-marathoner Scott Jurek recommends in his book Born to Run), where I briefly passed by in the middle, is what worked best for me. At this point, it was around 15-20% fat, which is moderate, but much lower than the standard American diet. I had good energy, I felt satisfied, and if I was mindful of my diet I was losing weight overall.

Maybe I am a special snowflake?

I think people go a bit too far with the “we’re all unique” angle, especially when it comes to nutrition. We’re ultimately all the same species, and I think the parameters of a “healthy diet” are far more narrow than most people seem to believe. I think hyper-individualist thinking can be used as an excuse for a garbage diet. What if I’m one of the 1% of humans who thrives on McDonalds and beer? Well, I might be, but I’m probably not, so I should instead stick to what healthy populations have done for centuries (again, outlined simply as “eat food, not too much, mostly plants”). We could nitpick specifics (I think fish is actually pretty healthy in moderation, but I avoid it for other reasons), but whatever. But individual proclivities do exist to some extent and it’s worth considering them, just as the ancient Romans did (or classical Chinese medicine, which pithily advises that if you are sick, eat less of what you eat a lot of, and more of what you eat little of).

I think metabolically speaking, the major diseases caused by lifestyle factors that affect most people are diabetes and high cholesterol (let’s call it glucose and lipids). Some people have both! Actually most do… sigh. Anyway, I believe that in the context of an overall healthy diet, it’s a bit of a trade-off. If you lean more towards fats, your glucose might be worse and lipids better. If you lean towards carbs, your glucose might be better and lipids worse. And maybe you want to be in the middle to get the best of both worlds.

For one, my personal proclivity is this: my glucose tends to be good and my lipids tend to be bad. Even at my least healthy, I avoided pre-diabetes, a fate that one of my closest friends who is ripped with visible abs 24/7 was unable to escape. But even at my healthiest, my cholesterol was a little bit too high. So based on my experiments, I want to avoid going too low-fat in the future, even if it worked for the Okinawans who I love dearly. If things were the other way around, maybe I’d make a different decision.

But you know what? I went into this experiment trying to be open to learning something, and it ended up giving me the answer I wanted. I had no business eating sweet potatoes all day because... I don’t have a sweet tooth! I think a lot of people do, but I quit (refined) sugar very easily and never understood why people called it a “drug”. On the other had, I do have a “fat” tooth, which is a term that I wish existed in the cultural zeitgeist. I go crazy for unsalted peanut butter, raw pistachios, plain avocados, and even raw silken tofu (which I have eaten on many occasions, don’t judge me). And throughout this discussion I am not talking about potato chips, cakes, cookies, etc, because apart from being processed foods which should be minimized, they are are high in both sugar and fat as well as sodium, which is the definition of a hyper-palatable food.

And this really got me thinking. What if this is not a coincidence? Again, in the realm of whole foods, what if the fact that I only need a bit of sweetness to be satisfied is because my body thinks I should focus on getting a bit more nuts, seeds, avocados? At this point, we’re getting into superstition. The body doesn’t “think” anything, we aren’t “built” for anything, I tend to have a very pragmatic view of things and am very wary of magical thinking and “just-so” stories. But it does make me wonder.

Anyway, coming out of this year of experiments (I didn’t intend for it to last a year, but it’s been that almost exactly) I am happy to have learned a lot about myself and what makes me feel good. I mostly don’t think I need to think about this much more, since things are good! Remember those ten pounds I had to lose? Well, it's down to five now! But, eventually, I had to go through this journey to learn this stuff and I’m glad I did it sooner rather than later.