Feed-back: Tune in — and your body will tell you how much to eat and when, experts say

Here come the holidays, and we all know what that means.

Chunks of cheesecake. Mounds of mashed potatoes. Turkey and dressing and cocktails, oh my.

Followed, of course, by a diet.

What will it be this time? Atkins? South Beach? How about the Chocolate Chip Cookie Diet or the Coconut Diet?

A better option? None of the above, according to people in the know. Rather, start listening to the signals that your body is constantly sending about when to eat and how much, and you'll be healthier. Throw in a little exercise, and you'll likely be lighter as well.

Most diets, by their very nature, are prescriptions for failure, says Linda Bacon, a nutritionist who has studied the phenomenon.

"Research certainly is showing us that dieting is useless," she says.

Americans spend more than $50 billion a year on diet programs and products, according to the MarketData research firm. One-fourth of men and nearly half of women in the United States are dieting on any given day, the group reports, and a good portion of the rest of us likely are thinking about it.

A recent study by the Calorie Control Council, an industry group that represents manufacturers of low-calorie foods, found that 62 percent of Americans are concerned about dieting year-round.

Yet even as we indulge our obsession with weight-loss books, pills, plans and programs, Americans keep getting fatter.

The Centers for Disease Control and Prevention reports that one-third of American adults are obese and 17 percent of our kids are dangerously overweight, numbers that have increased dramatically in the past two decades.

Nutrition specialists believe that diets are partly responsible.

While they may allow people to lose weight at first, diets that cut out entire food groups or focus on specific ingredients eventually backfire, says Bacon, who teaches at San Francisco City College and is on staff at the University of California, Davis. "Every major study shows that a majority of dieters gain the weight back, and sometimes more."

The reason, Bacon explains, is that when the human body suddenly takes in fewer calories and less fat, it goes into panic mode, telling the brain that it needs more food. As fat storage drops, so does the level of a hormone in the blood called leptin. When leptin dips below a certain level, it triggers an increase in appetite.