THE BODY MACHINE

For years there has been one standard answer for overweight people: you eat too much, or you exercise too little, or both. Doctors, nutritionists and dietitians all echo the "party line". Well, it simply isn’t true! There are people who get fat easily and people who remain skin and bones no matter how much they eat or how little they exercise. Not only can two people differ radically in their tendency to get fat, but the same person can change radically in his lifetime. Women who take birth control pills often gain more easily. The party line would be that they started to eat more or exercise less, but thousands of women claim the contrary.

The traditional approach to overweight can be shown by a drawing of a water tank. Water is added to the tank by a faucet above and let out of the tank by a faucet below. Humans are supposed to be just like this tank. Increasing the flow from the upper faucet is like eating more calories; when you do, the level in the tank goes up. Closing the lower faucet is like decreasing your daily exercise; the level of fat in your body goes up. Well, this analogy is partly true – getting fat is largely a matter of eating too much and exercising too little. Unfortunately, the analogy breaks down under practical everyday experience because it implies that people are passive reservoirs, affected only by outside food supply and exercise.

The fact is, we are not passive reservoirs or tanks, but active metabolizing machines, each different, each handling calories differently. I prefer to think of the body as a machine that runs efficiently or inefficiently, depending on circumstances. Just as an automobile may be tuned up properly to get more mileage from its fuel, the human machine also can become more efficient.

One of the unique features of the human machine is that it has two fuel tanks: one tank for sugar or, more technically, glucose and one for fat. Wouldn’t it be neat if our cars were built that same way? Anytime we ran out of gasoline, we’d just switch over to our diesel fuel tank. Actually, in our bodies, we don’t switch back and forth from one fuel to another; we use both simultaneously.

Most people are unaware that 60-70 percent of the energy muscles need when one is resting is supplied by fat. That is, fats, either from a recent meal or from fat deposits, travels through the blood to muscle where they contribute more than half of the resting muscle’s energy needs. Glucose and fats are burned side by side all day long, but fats supply most of the energy.

Storage of fat is therefore a natural body function. The trouble is, fat people’s bodies are overly proficient at storing fat and are less than normally proficient at burning it.

Our analogy with the tank of water doesn’t hold completely, because some people’s body machine work harder to store fat than other people’s. It isn’t simply a matter of "you eat too much or your exercise too little."

Furthermore, unlike the analogy with the water tank, being fat tends to make you get even fatter. Fatness is a viscous cycle; the more fat you have, the more your body chemistry, or metabolism, changes to favor the buildup of even more fat.