Even though Americans are more health conscious than ever, the prevalence of obesity is increasing. Over the past 10 years, the average weight of those in their 30s increased by four pounds and for those in their 40s, the increase was nine pounds. Helping the public to lose weight has become a multibillion-dollar industry and some clever marketers are suckering people to spend their hard-earned money on weight-loss scams that substitute gimmicks for will power. The public is inundated with diet books, magical protein formulas, pills, Rube Goldberg exercise machines, and weight-loss clubs. Yet, more people are waddling around than ever before. This is because many weight-loss programs start with the big lie: You can eat whatever you want and lose weight.
In actuality, for the vast majority of human beings, the only way to lose weight is to walk around hungry. The human body is a machine. It needs fuel to function. Cars don’t run without gas. Humans don’t run without food. When the car is out of gas, the gas gauge tells you so. When the human body is not ingesting enough food to function without metabolizing existing fat and muscle, it sends a signal to the hypothalamus. This signal is called hunger.
Humans evolved fighting the elements and each other with one quest in mind—avoid dying of starvation. It was only in the past few hundred years—hardly a tick of the evolutionary clock—that a significant percentage of humans began to eat three meals a day. Our remote ancestors were wandering tribes who starved for days until an accurate spear throw took down an animal. It is this evolutionary history that is programmed into our brains, not the behavior patterns of a society where $5.00 can buy you a package of oreos and a gallon of milk.
Not only is it difficult to lose weight, but keeping weight off is an even greater challenge. A recent study at Rockefeller University demonstrated why. The researchers quantified the energy expended by individuals who had dieted and lost 10% of their body weight. The results showed that the dieters had a decrease in body energy expenditure, even when accounting for the loss in body mass.
Perhaps an example will make this clearer. Let’s say a woman requires 2,000 calories a day to maintain her weight. She goes on a diet and loses 10% of her weight. It would follow that she should be able to maintain her new weight by eating 1,800 calories a day (10%less than 2,000 calories); but this is not the case. She has to eat in the range of 1,650 calories or else she will regain the weight she lost. This is why so many people keep gaining and losing the
same 15 pounds.
Thus, the human body is not only programmed to avoid weight loss, but to return to its previous weight after an episode of weight loss. Why is this? Again, let’s go back to our primordial ancestors wandering the plains in search of food. If the spear chuckers went into a slump, there were no 7-11’s around to pick up a bag of Doritos. To prevent the tribe from starving, Mother Nature developed a mechanism that allowed the human body to utilize the little food available with greater efficiency — starvation metabolism.
Many weight-loss programs correctly emphasize the importance of exercise, but again, discipline is crucial too. More exercise simply increases one’s appetite, just like driving a car a further distance requires more gas. This is why lumberjacks eat more than accountants. Muhammad Ali is right. The best exercise is the push away from the table.
Clever marketers have been successful at selling the gullible overpriced, unpalatable low-fat foods. Dietetic cheese, bread, beer, and ice cream proliferate on the supermarket shelves. There are even low-fat donuts! Many of my patients have told me that you can’t add fat to your body if you eat low-fat food. This simply isn’t true. The human body merely converts excess calories into fat. Gobbling a dozen low-fat donuts is a great way to force yourself to buy a new wardrobe. As fewer workers make their living by manual labor, weight control is paramount to the country’s collective health. Some physicians are advocating treating obesity as a chronic disease similar to hypertension and diabetes. Leveling with our patients by informing them that weight control requires discipline and occasional hunger pains would be a good start.