The challenge of dealing with the obesity epidemic is one of the most interesting debates in the field of human health. Most people feel the answer is already there, “eat less and exercise more stupid.”
Not so fast. The body has feedback mechanisms in place to maintain a constant weight. If you eat too little, metabolism slows down and you get more hungry. If you eat too much, metabolism speeds up and you get less hungry. Anyone can gain or lose a few pounds by suddenly changing exercise levels and food intake before these homeostatic mechanisms catch up, but going beyond those parameters is difficult unless the feedback mechanism is broken. The feedback loop is broken when there is inequality between the metabolic rate and hunger levels. An overweight person craves more food than their metabolic rate is set at. How can this happen?
The real questions to ask are, “what governs metabolic rate?” and “what governs hunger levels?” Metabolic rate, for the most part, is governed by the number of calories that are available to the active tissues as fuel. Hunger is something that arises when active tissues aren’t receiving the amount of energy needed to function at optimal levels. Thus, both low metabolic rate and high hunger levels are caused by the exact same thing – shortage of fuel available to the active tissues.
If you eat a lot of calories, then why wouldn’t your active tissues be getting enough fuel? Interestingly enough, a list of the hormone insulin’s functions include: diverts ingested energy into storage in fat cells, blocks the release of energy from the fat cells, and clears glucose, another form of energy, from the bloodstream. All of these functions make energy unavailable to the active tissues. Here’s the significance:
Because of insulin’s fuel-storage properties, the higher your insulin levels, the more food you must eat to satisfy your hunger, even if you are storing fat. Actually, you must eat more because you are storing fuel instead of being able to use it. Secondly, with high insulin levels you can store fat while starving your active tissues on a low-calorie diet. This leads to a lowered metabolic rate (which is set to the amount of calories the active tissues receive), and chronic hunger, urging you to supply more fuel. Also, because insulin clears sugar from the blood, the higher your insulin levels the more you crave sugar.
This is interesting, as fructose, the type of sugar that comprises half of table sugar, and 55% or more of High fructose corn syrup, has been shown in several studies to cause hyperinsulinemia, where the body secretes more insulin than normal. A vicious cycle maybe? You bet. Now it makes sense that the prevalence of obesity patterns the dramatic rise in the consumption of refined sugar, the biggest dietary change that Americans have undergone in the last century – or ever. Wonder why it’s soared specifically since 1980? That’s when the food industry switched from sucrose (50% fructose) to high-fructose corn syrup (55% fructose or higher). This parallels an enormous spike in sugar consumption per capita, overall carbohydrate intake, overall caloric intake, and accelerating rates of obesity, diabetes, and other disorders related to hypersinsulinemia. Finally, something makes sense. Refreshing isn’t it?
Reversing this cumulative disorder is actually quite simple. You merely have to lower insulin levels, which kills hunger by allowing ingested food to make it to the active tissues while releasing excess energy that’s been locked up in fat cells. This suppresses hunger even more, and the metabolic rate rises in response to the surplus of available fuel (which also, amazingly, restores muscle and bone mass without weight training). To lower insulin, you must switch from a fuel source that raises insulin levels to one that does not – fat instead of carbohydrates. As long as you don’t go too low in carbohydrates to induce ketosis (Atkins), and choose starchy carbohydrates over sweet carbohydrates, you will succeed. All you need is persistence. This is the only way that the root problem of fat accumulation (imbalance between hunger and metabolic rate) can be dealt with without encountering contradictory feedback mechanisms – lowered metabolism and increased hunger, which lead to the yo-yo effect caused by virtually every other diet program ever created. The result here, predictably, is increased metabolic rate and decreased hunger, a win-win – the result of returning to homeostasis. Instead of telling people to eat fewer calories and burn more, why not simply provide the recipe for making that happen biologically, automatically, without willpower?