Getting fat is a metabolic disorder. An evolutionary take on Paleo and Low Carb Diets.

Last year I wrote a couple of posts supportive of Gary Taubes’ book Why We Get Fat. I’m still a believer so wanted to do an update. Though I’ve tried to be careful in noting below where Taubes’ view differs from the scientific consensus.

Let’s start by recapping my post Two Models of Why We Get Fat, which contrasts the “energy balance model” with the “kinds of foods model.”

The energy balance model argues all calories are the same. So calorie counting is all you need to do. A calorie is a calorie. This is no longer the scientific consensus. From last’s year’s post:

The energy balance model asks us to believe something as essential as food intake regulation breaks down in an ideal living environment with plenty of food and rest. If taken at face value we should expect animals, which share much of our regulatory framework, to have this same problem. So for example if zebras exercise too little or too much, and don’t constantly track their diets on their iPads, we’d expect they get fat or starve. Of course evolution doesn’t build such fragile solutions. The energy balance model ignores the central problem, which is to explain why an exquisitely tuned regulatory system for adjusting food intake breaks down in the first place.

So what about the other model? Well, in that model eating food your body is maladapted for leads to hormonal dysfunction, signally the body to create more fat cells than needed. In turn, this triggers the regulatory system to eat more. The correct analogy is how taking steroids builds excess muscle tissue, making you eat more to compensate. Think of junk food as fat steroids and you get the picture. We eat more because the body (incorrectly) decided to build too many fat cells, not the other way around. The energy balance model has it backwards.

Taubes argues refined carbohydrates are the dietary culprit. His argument is simple: 1) eating refined carbohydrates leads to an overproduction of insulin, 2) insulin metabolically regulates fat (steroids for fat), 3) excess carbs make us fat. Solution: eat a low carb diet. Of course this thesis is contested. In any case, I think the general idea of controlling your weight by altering the kinds of food you eat, rather than the amount you eat continues to gain scientific traction. Getting fat is a metabolic disorder, not a failure of will. In my second post I summed this up by saying:

1. Exercise is great, but don’t use it to lose weight.
2. Don’t waste your willpower trying to eat less. That fights your body’s automatic food intake regulation to no effect, and leaves you feeling hungry all the time.
3. Instead, use whatever diet willpower you have to avoid junk food. Unfortunately the science on exactly which types of food are junk food isn’t settled, but it’s safe to say you should avoid sugar. And while avoiding junk food, eat allowed foods until you are full.

So on to the new stuff. In the past year the Paleo diet has overtaken Low Carb Diets in popularity. Though most doctors remain skeptical of both. And admittedly the caveman marketing aspect of the Paleo diet is faddishly annoying. So many science types are dismissive. After all, most cavemen died young. Not really my plan. Of course the Paleo diet is also a low carb diet, much as the Mediterranean diet is. Which is why they both work (in my Taubes influenced view). In fact the Paleo diet has a strategic edge over most other diets because it’s ultimately built on an evolutionary argument. This makes the Paleo diet adaptable to new scientific findings, which is why I think it will outgrow it’s faddish youth. But I get why others are skeptical and think it will retain it’s cult faddish side. Getting fat is an evolutionary mismatch between our current environment and the one we’re evolved for, so taking an evolutionary approach should ultimately prevail.  Taubes of course is a fan.

So what are some new approaches to understanding about why we get fat?

• Evolution. As mentioned, Paleo is part of a larger shift in looking towards genetics and evolution as the proper way to to understand diet. A good thing.
• Antibiotics. Antibiotics can make you fat by altering gut microbes, which in turn disrupts your metabolic regulatory balance.
• Gut Microbes (beyond just antibiotics aspect). Living in colder climates may modify your gut microbe population imbalances, making you fat. Also, it’s surprising that changes in gut microbes may be why stomach surgery works.
• Genetics. Some people carry genes to better digest carbohydrates. A recent genetic innovation selected for since the advent of agriculture. So while carbs may cause you to get fat, some people have a better genetic tolerance for high carb diets.

Some great science going on right now. If antibiotics and gut microbes are key factors, the pure form of the low carb thesis needs caveats. With that said, the easiest way of altering your gut microbe population is by changing, you guessed it, the kinds of food you eat. Not the amount of food you eat.

This blog is an attempt to understand future directions in science and technology, and their impact to society at large. This includes nutrition science. I continue to be convinced some form of Gary Taubes’ low carb thesis will prevail. In particular I like Taubes’ severe take down of observational diet studies, which hunt for data correlations after the fact. But of course the problem with speculating about the future is it’s easy to be wrong. So there’s that.

For now I’m viewing carb intake as a dial. If I gain weight, crank it back a notch. This “medium carb” approach works for me. Though each year that goes by I have to turn the dial a bit further. Less pizza this year than last. My plan is to cut back on non-essential carbs as needed to allow continued (moderate) consumption of two essential beverages: Pinot Noir and Bombay Gin. Your approach may of course vary. Say, chocolate. Would not be my pick. But to each his own.

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Appendix: My “medium carb” diet cheat sheet

When I first changed diets a couple of years ago I did some light research on Atkins and other low carb diets. The result is below. Taubes’ book in fact doesn’t give any particular food advice, it’s all about the science, which of course is why I liked it so much. What worked for me was bucketing food by carb level. The purpose of sharing is to drive home what a low carb diet looks like if you haven’t seen one before. Which I hadn’t until after reading Taubes’ book.

AVOID
refined sugar: candy, chocolate, frosting, syrup, honey
sugar drinks: juice, non-diet soda, kool-aid, milkshakes
carb drinks: beer, energy drinks, sports drinks (unless exercising)
sugar desserts: cake, pie, cookies, ice cream, doughnuts, cupcakes

ON OCCASION
grains: bread, pasta, rice, noodles, couscous, flour, tortillas, macaroni, pizza, rolls, muffins, pastry, buns, bagel
processed grains: chips, pretzels, breakfast bars, granola bars, breakfast cereals
high sugar fruits: grapes, bananas, cherries, oranges, plums, pears, pineapple, jam, jelly
high sugar dried fruits: dates, raisins, dried apricots
most root vegetables: potatoes, beets, sweet potatoes, yam
high carb vegetables: peas, corn
low fat dressing (replaces good fats with bad carbs)
yogurt with sugar or fruit

IN MODERATION
low sugar fruits: blackberries, blueberries, strawberries
moderate sugar fruits: watermelon, peaches, nectarines, cantaloupes, apples
cheese, vanilla or plain yogurt

EAT ALL YOU WANT
meat: chicken, beef, pork, hamburger, steak, sausage, lamb, turkey
prepared meat: ham, salami, bacon, meat hotdogs
seafood: fish, lobster, crab, tuna, salmon, white fish, clams, calimari
fats: butter, cream, blue cheese dressing
tofu
eggs
low carb vegetables: lettuce, spinach, collards, herbs, celery, radish, cabbage, mushrooms, asparagus, okra, cucumbers, green beans, broccoli, cauliflower, peppers, yellow squash, zuchnni, green onions, brussels sprouts, leeks, tomatoes, onions, olives