OBESITY AND OVEREATING: CHICKEN AND EGG, PART I
Listen to people who aren’t certified nutritionists — like personal trainers, white-collar workers, and government officials — and you’ll hear a very simple and often-repeated refrain about obesity. It goes like this “Calories in minus calories out equals fat gained.”
Everyone in the world would really like obesity to be that simple: eat less, burn more calories, and you’ll lose weight. Unfortunately, a huge number of people in the world can tell you from experience that it doesn’t always — or even often — work that way. The truth is far more complex.
If you’re not sure how much more complex, think about this one thing: water has zero calories. If you drink a quart of water, you just gained two pounds. If pounds are purely a matter of calories in and out, gaining two pounds without consuming any calories wouldn’t make any sense at all.
But of course that’s just the simplest possible example. The deeper truth is that the shape of your body and the disposition of your fat is determined by hormones. Insulin in particular is actually 100% necessary for your body to create fat; your body simply won’t make fat without insulin in your bloodstream.
Now, hormones are also responsible for controlling our eating behavior. That’s right — you don’t overeat because you’re a gluttonous pig; you overeat because your insulin, leptin, and ghrelin levels aren’t where they’re supposed to be. Are you ready for thereal painful reveal? Those ‘hunger hormones’ are created by fat cells.
So what laypeople tell you is that you’re fat because you overeat, but what nutritionists know — and have known for decades — is thatyou overeat because you are fat.
That, of course, leaves us with the burning question: what makes us get fat in the first place? The controversy over the answer to that question is why we have so many diets in the world and so few of them work. We’ll talk about it in Part II.
