There is a science to weight loss, but the facts often are obscured by the myths. For example, the calories-in, calories-out theory says that for every 3,500 calories you lose, you drop a pound of fat. If you follow this logic, a 150-pound woman who reduced her daily caloric intake by 100 calories (the amount in less than one cup of reduced-fat milk) for 10 years would give up 365,000 calories—and would weigh only 46 pounds!

Despite what you’ve heard, calories are not all that matter…they’re not all the same…and the government’s dietary guidelines are not effective for weight control.

What really works…

Eat more to lose weight. It’s true. People who consume more food gain less weight than those who cut calories—but only as long as the calories come from the right foods.

Example: When researchers at the University of Pennsylvania compared the effects of higher- and lower-calorie diets, they found that people who ate more lost 200% more weight.

A diet high in high-quality foods (such as protein-rich seafood, nuts and seeds and nonstarchy vegetables, such as celery, asparagus and salad greens) increases satiety, the ability of calories to fill you up and keep you full. The same foods are less likely to be stored as body fat than, say, processed foods, and they’re more likely to be burned off with your normal metabolism.

People who eat less to lose weight usually fail because the body interprets calorie restriction as starvation. For self-protection, it hangs on to body fat and instead utilizes muscle tissue for energy. Up to 70% of the weight that people lose on a low-cal diet actually is muscle tissue, not fat.

When we eat more—but smarter—we are satisfied…eat only the number of calories that we really need…and provide our body with an abundance of nutrition. This enables us to sustainably burn body fat.

Focus on protein. Protein is a high-satiety nutrient that triggers the release of hormones that send I’ve had enough signals to the brain. In a University of Washington study, participants were allowed an unlimited amount of calories as long as 30% of those calories came from protein. Result: They consumed 441 fewer calories a day—without feeling hungry.

Protein is less likely to be converted to fat. When you eat an egg omelet or a chicken breast, about one-third of the protein calories are burned during digestion…another one-third are burned when the liver converts protein to glucose (a process called gluconeogenesis).

Compare this to what happens when you eat bread or other starchy foods. About 70% of those calories can be stored as fat.

Recommended: Get one-third of your calories from protein—in the form of seafood, poultry, meat or nonfat dairy, such as plain Greek yogurt or cottage cheese.

Don’t neglect fiber. This isn’t new advice, but most people still don’t get enough fiber—or understand why it helps.

The fiber in plant foods isn’t digested or absorbed. Instead, it takes up space in the digestive tract…and makes you fill up faster and stay full longer. This is why you will feel more satisfied when you eat, say, 200 calories worth of celery instead of 200 calories worth of candy. The celery takes up about 30 times more space.

You don’t have to “count” fiber grams. As long as you get about one-third of total calories from nonstarchy vegetables (discussed previously), you’ll get enough.

Don’t believe the claims about grains. Whole-wheat bread, oatmeal, brown rice and other grains will not help you lose weight.

Reason: The calories in grains are aggressive, which means that they’re more likely to be stored as fat than the calories that you get from protein or nonstarchy carbohydrates. Grains—even whole grains—are rapidly converted to glucose (blood sugar) in the body. The rapid rise in glucose is followed by an equally rapid drop-off. This stimulates the appetite and causes you to crave more calories.

Also, fast-rising glucose is hard for the body to handle. It responds by attempting to rid itself of glucose—by storing it in fat cells.

Eat fat. It’s true that fat has about twice as many calories as protein or carbohydrates, but that would matter only if the calories-in, calories-out equation had anything to do with weight loss—which it doesn’t.

Decades ago, doctors encouraged Americans to consume fewer calories from fat. Result: The average person got heavier, not leaner. Experts now agree that people who consume more fat are no more likely to be overweight or obese than those who eat less—if anything, the people who eat less fat are more likely to gain weight.

Recommended: Get about one-third of your calories from fats, including olive and canola oils (monunsaturated fats that lower your risk for heart disease) and the fats in meats, poultry and fish.

Drink a lot of green tea. You will naturally burn more fat when you drink more water. If you get much of this water in the form of green tea, you will do even better. The polyphenols in green tea are among the healthiest antioxidants ever discovered. These compounds, along with the caffeine in tea (about one-fifth the amount in coffee), increase fat metabolism. If you drink decaffeinated tea, you still will burn more fat than you would just by drinking water.

Recommended: Between five and 15 cups of green tea daily. For maximum efficiency, put all the tea bags you need for the day in hot water. Let the tea brew for a few minutes, and then drink the tea throughout the day like iced tea…or put it in the microwave if you prefer hot tea.

Source: Jonathan Bailor, a health-and-fitness researcher based in the Seattle area, who analyzed more than 10,000 pages of academic research related to diet, exercise and weight loss for his book The Smarter Science of Slim: Scientific Proof, Fat Loss Facts (Aavia). www.TheSmarterScienceOfSlim.com