Because eating is a voluntary act, we tend to blame obesity on lack of willpower, but if this were so, why are so many Americans overweight now compared to 50 years ago? Why would so many of us lose our willpower? It doesn’t make sense. Many overweight folks display remarkable discipline in other areas of their lives.
Remember when you were a kid and you tried to see how long you could hold your breath? It was easy at first, but soon carbon dioxide built up in your blood, stimulated chemical receptors in your brain and overcame your willpower. You quickly learned that you can’t resist the demands of your body chemistry.
A similar thing happens when you try to lose weight by just trying to reduce the amount of food you eat. Powerful hormonal reactions take place that make you hungrier than ever. You can’t resist eating. You end up gaining back more weight than you lost.
The amount of fat you carry is not under your command. It’s mostly determined by the balance among several hormones, some of which make you gain fat and some of which make you lose it. Obesity is an imbalance of these hormones. The problem for most overweight individuals these days is that their body produces too much of an especially powerful hormone that makes you gain fat. That hormone is insulin.
Insulin is known best for its effects on blood sugar. It transports glucose out of your blood and into the various cells of your body. The more carbohydrates you eat, the more glucose enters your bloodstream and the more insulin you have to produce to keep your blood glucose from rising to harmful levels, which is what’s called diabetes.
But insulin does more than keep glucose from building up in your blood. It’s the body’s most powerful calorie-storing hormone. If you consume more glucose than your body needs, insulin pushes the remainder into your fat cells where it’s turned to fat. (Take note of that: Insulin turns glucose to fat. That potato you had last night? Insulin turned it to fat and it’s now resting on your thighs.)
But glucose is not the only thing insulin transports into your fat cells; it pushes fuel from all three major sources of calories–carbohydrates, fats and protein–into your fat cells.
This process works both ways, or at least it’s supposed to. Between meals insulin levels normally drop, which allows fuel to leave your fat cells and travel to the rest of your body to provide energy and curb your hunger. The problem is that if you have too much insulin in your system–hyperinsulinemia–insulin levels stay high between meals. Insulin keeps trying to push fuel into your fat cells instead of letting it out. It “locks” fuel into your fat cells so it can’t get to your appetite control centers to keep you from getting hungry or to the rest of your body to provide energy. You eat a big meal, but a few hours later you’re hungry again. Scientists call this “internal starvation.” Your fat cells thrive while you go hungry. Your fat acts like a giant tumor, pulling fuel out of your bloodstream, robbing you of nutrition as it grows.
Because the fat cells in your abdomen are more responsive to insulin than those in other parts of the body, this kind of fat accumulation goes right to your abdomen. Your arms and legs may end up being disproportionately thin.
