THE | DIET DETECTIVE^®

According to the Pew Research Center, about a third (34 percent) of Americans are neither exercising nor dieting; 17 percent are doing both; 8 percent are dieting but not exercising; and 40 percent are exercising but not dieting.  So, who is right?

Well, a recent study appearing in the Journal of Clinical Endocrinology & Metabolism demonstrated that dieting and exercise are equally good at taking off the pounds - as long as the number of calories consumed is the same as the number of calories burned. However, keep in mind that this was just one study, and it was short term.

According to the Pew Research Center, about a third (34 percent) of Americans are neither exercising nor dieting; 17 percent are doing both; 8 percent are dieting but not exercising; and 40 percent are exercising but not dieting.  So, who is right?  Well, a recent study appearing in the Journal of Clinical Endocrinology & Metabolism demonstrated that dieting and exercise are equally good at taking off the pounds - as long as the number of calories consumed is the same as the number of calories burned. However, keep in mind that this was just one study, and it was short term.

It's difficult for someone doing just exercise (without diet) to lose weight and keep it off. And most studies agree that you need a combination of exercise and diet for long-term weight-control success. "Weight loss requires a two-pronged approach: Eat healthfully and exercise," says Milton Stokes, R.D. M.P.H., spokesperson for the American Dietetic Association.

Think about which you would rather do: Skip the mayo on your burger, or walk it off for 35 minutes. The key point here is that it takes both. You need the exercise to rev up your metabolism so that it burns more fuel. It's unlikely that doing one without the other will work.

And, according to David L. Katz, M.D., associate professor of public health and director of the Prevention Research Center at Yale University School of Medicine, the answer is simpler than the debate would imply. "It depends," he says. "Weight loss occurs whenever you burn more calories than you take in. If you can exercise enough to burn more calories and would rather do that than cut calories, then exercise is the way to go. If, however, you're more willing to trim your portions than go out running, dieting will work better."  That said, it's clear from the research that the majority of people who have lost weight and kept it off for five years or more combine diet and exercise. In fact, "It's nearly impossible to exercise enough to control weight without attention to diet," adds Katz. And, conversely, it's nearly impossible to sustain weight loss without some increase in physical activity.   In addition, an increase in physical activity offers other benefits, including cardiovascular health, and strength training can add muscle, which can burn extra calories at rest (each pound of muscle added will increase the calories your body burns by about 30-50).

Also, it's important to note: "Many truly obese people don't eat much but don't move much, either (hence their weight stays the same). Some are eating at starvation levels but sit in a chair all day.  If these people would start moving, they would begin to lose weight," says Stephen Rice, M.D., Ph.D., M.P.H., a sports medical expert at the Jersey Shore Medical Center in Neptune, N.J.

Should you eat three or six meals per day?
The answer is that it really depends on whether those six meals are going to increase or decrease how many calories you take in for the day overall. According to Stokes, "A small amount of research says that eating mini-meals consisting of less food more frequently may help rev metabolism and prevent extreme variations in blood sugar.  At the very least you should eat three times daily.  Some people reap benefits from eating about every four or five hours daily.  That isn't, however, a license for going hog wild all day."

People get hungry every four hours, says Nancy Clark, a Massachusetts-based sports nutritionist and author of Nancy Clark's Sports Nutrition Guidebook (Human Kinetics, 2003).  She recommends four meals made up of breakfast, two lunches with about three hours between them, and dinner. She believes that eating the two lunches will lessen your appetite during dinner and solve the energy problem that most people have. Her motto: "Fuel by day, diet by night."

Katz favors six meals because, "People trying to control their weight are often worried about deprivation and going hungry. Having food available at regular intervals cuts off this anxiety," he says.

"I caution people about the six meals per day," says Lona Sandon, M.Ed., R.D., a professor of nutrition at the University of Texas Southwestern Medical Center at Dallas.  "There is nothing magical about six meals per day, and any opportunity you give yourself to eat is an opportunity to overeat.  Six meals a day at 300 calories each would be a total of 1,800 calories for the day.  A bowl of cereal with skim milk and maybe 1/2 cup of juice would be about 300 calories.  People who follow this type of plan need to really watch their portion sizes."

Katz agrees. He believes that if you are eating often, you must make sure you're eating well. You have to be even more vigilant.

Which is better for you - walking for 15 minutes each day or going on an all-day hike on the weekend?
It's pretty much unanimous among health experts: The daily walk, even for a few minutes, is better than the all-day hike on the weekend. According to Dr. Rice, "Daily exercise is superior to being a 'weekend warrior.'   Couch potatoes Monday through Friday and vigorous athletes Saturday and Sunday can come up with both acute and overuse injuries easily."

Not only that, but if you have the time to walk 15 minutes each day, it is better for your health and fitness, and, according to Michael R. Bracko, Ed.D., a spokesperson for the American College of Sports Medicine, these short walks can be the start of bigger and better things for fitness and health and could ultimately change your life.

CHARLES STUART PLATKIN is a nutrition and public health advocate, author of The Diet Detective's Count Down (Simon & Schuster, 2007) and founder of DietDetective.com, the health and fitness network. Copyright 2007 by Charles Stuart Platkin. Sign up for the free Diet Detective newsletter at www.dietdetective.com.