Calorie restriction is the worst idea ever

I recently visited the website of the Calorie Restriction Society, an organization that believes humans can have longer and better lives if they voluntarily limit the amount of food they consume. It's an entertainingly retro idea, like playing tennis with a wooden racquet, but the site has some deadly serious warnings about the dangers of cutting calories too quickly and too drastically. Among the horrors: • Depression • Loss of strength and muscle mass • Deteriorating bone mass • Hormonal disruption, including lower testosterone in men and amenorrhea in women • Diminished energy and sex drive Remember, these warnings come from a group that exists to convince people to eat less. How much less? According to one study, they eat between 1 ,400 and 2,000 calories a day, in a country in which people typically wolf down 2 ,000 to 3,000 or more a day. Which brings me to The Sonoma Diet, a book that hit the New York Times best-seller list in early 2006. You know how many calories the author recommends for those just starting her diet? Between 1 ,200 and 1 ,400 a day. Yes, the maximum calories she allows in the first phase of her diet is equal to the fewest calories eaten by members of a cult who try to live longer by teetering on the precipice of starvation. This "rapid weight loss " phase is only designed to last ten days, but still, starvation is starvation. And naming a book after a beautiful place like Sonoma County, California, doesn't change that equation. So with those scary thoughts in our minds, let's talk about calories.In my view, there are two fundamental approaches to weight loss: In the traditional approach, the one that advocates cutting calories, you are making two sacrifices for the goal of a smaller and leaner body: • You 're going to lose muscle mass. • You 're going to slow down your metabolism. The metabolic slowdown has two causes. Losing muscle means you have a slower resting metabolic rate. But eating less also slows down your metabolism. About 10 percent of the calories you eat are burned off during digestion. The technical term for this is "thermic effect of food," or TEF. If you're in what's called "energy balance " -that is, you're eating and burning off the exact same number of calories over time, and not gaining or losing weight-then TEF accounts for about 10 percent of your metabolic rate. Thus, eating a lower-calorie diet decreases the TEF. Let's run some numbers: Say you eat 2,000 calories a day, and you're in energy balance. Call it the Goldilocks Diet-neither too many calories, nor too few. About 200 of those calories are burned off during digestion. Now let's say you decide to go on the Wicked Step-sister Diet, and you cut 500 calories a day. Aside from leaving you pretty damned hungry, you're also slowing your metabolism by about 50 calories a day. Now your TEF is about 1 50 calories a day, instead of 200. On top of that, you're certainly going to lose some muscle mass. A study out of Washington University in St. Louis put a group of late-middle-aged men and women on a calorie-restricted diet for a year. They lost about 18 pounds, on average, which was about 10 percent of their body weight. (Remember, this was a mix of men and women.) They also lost 3.5 percent of their total lean mass-muscle, bone, and everything else that isn't fat-as well as 7 percent of the muscle in their thighs. Sacrificing 3.5 percent of their working parts in a year also led to decreases in strength and aerobic capacity. I mentioned in Chapter 2 that strength is correlated with longevity in both men and women. The relationship between aerobic capacity and longevity is pretty strong, too; in a Cooper Institute study published in 2002, middle-aged women with moderate aerobic fitness were about half as likely to die of any cause as the women with the lowest fitness levels . (Curiously, the women with the highest aerobic fitness had a higher death rate than the middle group, although the rate was still 43 percent lower than that of the least-fit women.) Put another way: A chronic low-calorie diet is a death wish, and the slowdown in metabolism is only a small part of the problem. Is there a better way? Damned glad you asked. Traditional weight-loss advice: "Eat less and exercise more. You've heard it more times than you can remember. I 've heard it, too, but being male, I have a magical ability to filter out half the equation. I'll hear "Exercise more," and develop a strategy for that. If men like me hear "Eat less," it usually means "Eat a salad instead of a microwave burrito." And even that is usually too much dietary discipline to expect from my gender. But let's get back to you, and take a closer look at "Eat less and exercise more. " I hope I've convinced you by now that "Eat less " is a formula for slowing down your resting metabolic rate. And "Exercise more" is a way to increase your metabolic rate. The combination, however, can be expressed this way: Slow down your metabolism while speeding it up. Does that sound reasonable? If a financial advisor told you to run up your credit cards while putting away money in a savings account, would you take that advice? Or would you get out of his office as fast as you possibly could, employing both of your anaerobic energy systems? Would you say to your employees that you want them all to start working longer hours, and as a reward, you're going to pay them less? If you made that announcement on Friday, would anyone show up on Monday? To put it into a political context, it's the equivalent of "I voted for it before I voted against it. " It is, to put it as simply as I can, illogical. The reward of eating less is that you have to eat even less as you lose weight and your metabolism slows down. I don't know about you, but I can't imagine that I'd be happy if all I got out of starving myself down to a smaller waist size is that I got to experience even deeper levels of starvation. Let's get back to that U.S. Department of Agriculture study I mentioned in Chapter 3: The women cut 50 percent of the calories from their diets, and the result was a loss of about 10 pounds of lean tissue in twelve weeks, which slowed their metabolic rates by 9 percent, which made their exercise so efficient that they burned 16 percent fewer calories while doing it at low intensities. You wouldn't take a deal like that in any other aspect of your life, and I hope I can talk you out of accepting it as the best way to lose weight. In fact, I don't even like the phrase "weight loss ." To me, it implies indiscriminate weight loss, as if it's equally beneficial to lose fat or muscle tissue, as long as the needle on the scale doesn't go as far to the right. I like to frame it differently, and talk about "fat loss." Now we know we 're focused on the specific goal of shedding one type of weight, while preserving muscle tissue.