"Every calorie that comes in must be used up by your body or it may become fat," says Lola O'Rourke, RD, nutrition consultant based in Seattle and a spokeswoman for the American Dietetic Association (ADA).

So keep it simple. Here are some easy, time-tested diet dos and don'ts that may help you do just that.

Do Stock Your Kitchen With Healthy Food
"Healthy weight starts with healthy shopping," says O'Rourke. "Use a shopping list to curb impulse buying, don't shop when you're hungry, and be aware that items are strategically placed in the store to entice you to buy things you didn't plan to buy."

Shop for quick low-fat food items, say nutrition experts at the National Heart, Lung and Blood Institute. Fill your kitchen with lower-calorie basics:
Fat free milk, yogurt, and cheese
Eggs/egg substitutes
White meat chicken or turkey
Fish and shellfish (not battered)
Dry beans and peas
Fresh, frozen, and canned fruits and vegetables

Don't Watch Too Much TV
Though television's relationship to obesity may not seem obvious, more and more research appears to show that the more TV, the fatter you're likely to be.

"There are many possible reasons for this association, such as being exposed to more food commercials, having less time for exercise, and the like," says O'Rourke. "Most of the research has been done on children and adolescents, but it is reasonable to assume that the association will hold among adults.

In just one of these studies, public health experts examined the relationship between television watching, calorie intake, physical activity, and obesity in more than 4,000 American 8- to 16-year olds.

Nearly 50% of the children watched more than two hours of television per day, with boys on average watching slightly less than girls.

What the researchers found was more television equaled greater obesity. As hours of television watched increased, levels of obesity rose, too. The scientist's results, published in the March 2001 Archives of Pediatrics and Adolescent Medicine, showed that obesity rates remained lowest among children who watched an hour or less of TV per day.

Do Make Healthy Snacking Part of Your Plan
Small, more frequent meals are a good way to help keep food cravings at bay. A handful of walnuts at mid afternoon is probably better than a candy bar.

Spacing meals and snacks three to four hours apart helps
keep the body fueled, says the ADA. It recommends you choose foods that are high in complex carbohydrates such as foods made with whole wheat. Add a small amount of protein to stay fueled longer. Try bean dip, peanut butter, or cottage cheese.

Healthy snacking can help you enjoy eating and keep you energized throughout the day.

Don't Fall Prey to Fad Diets
If you want to know whether a diet you are considering is a fad, here's how the ADA says you can tell. Does your diet

Promote miracle foods or formulas,
Require little or no physical activity,
Focus on quick weight loss,
Provide rigid menus and plans,
Encourage specific food combinations, or
Guarantee success?

Any "yes" here means you're likely looking at a fad diet.

"It's easy for even very, very intelligent people to get caught up in the hype and fantasy around fads, be they diets or supplements," says Melinda Manore, PhD, RD, chairwoman of the department of food and nutrition at Oregon State University. "Avoid taking dietary advice from peers and neighbors. If you want to achieve weight loss, you should consult a certified health professional to develop a weight-loss plan.

Do Add Healthy Foods to Your Diet
"Instead of focusing your efforts on making certain foods, like red meat, off limits, it is better to concentrate on adding foods you enjoy to your diet," says Ruth Kava, PhD, RD, nutrition researcher with the American Council on Science and Health.

For example, she recommends you:
Try cholesterol-lowering oatmeal for breakfast.
Eat nuts rich in monounsaturated fat, such as almonds, pecans, and walnuts.
Add beans to leafy salads, pasta, and stews -- chick peas, kidney beans, and navy beans may reduce LDL "bad" cholesterol

Don't Be Afraid to Quit Smoking
"I work with so many people who are concerned about whether they should eat this or that, or how many calories of this food, and that's fine," says Kava. "But quitting smoking is the single biggest way anyone can improve their health. So don't let fear of weight gain keep you smoking."

On average, people who quit smoking gain only about 10 pounds, say experts at the National Institute of Diabetes & Digestive & Kidney Diseases. To avoid post-smoking weight gain after you quit, you need to become more physically active, improve your eating habits, and develop a treatment plan with your doctor before you stop.