One persistent misconception underlying many fad diets is that certain foods or food groups can improve health and athletic performance, and aid in weight control. The Grapefruit Diet, the Pineapple and Papaya Diet, the Cabbage Soup Diet, and the new Fat-Burning Fruits Diet are all based on the premise that including specific foods in your diet can trigger your body to burn fat. Other diets promote the exclusion of entire classes of foods to stimulate weight loss. For example, during the 1940s and 1950s starchy foods developed a reputation for being fattening. This led to the development of high-protein, low-carbohydrate weight loss programs like the Scarsdale Diet, which encouraged adherents to avoid carbohydrates, but eat all the lobster dipped in melted butter they wanted.

In the 1980s nutrition scientists declared that fat, not starch, was the enemy when it came to the battle of the bulge, and decreed everyone should eat a high-carbohydrate, low-fat diet to ensure health and promote weight management.

The mid-1990s have seen a bit of a backlash with respect to the high-carbohydrate diet movement. Although many Americans were eating significantly more carbohydrate-rich foods their weight was higher than ever. Several reasons for this unanticipated result have been identified: 1) people often unwittingly replace high-fat foods with low-fat, high-sugar foods not realizing many low-fat confections get their flavor boost from sugar. 2) Having been encouraged to eat more carbohydrates people ate extra large portions of low-fat, high-sugar foods. 3) Some people who ate diets rich in complex carbohydrates (starches) overate because they felt constantly hungry. 4) Scientists discovered approximately 20% of the US adult population is carbohydrate sensitive. These people have an impaired ability to metabolize glucose, and eating high-carbohydrate diets left them feeling sluggish, and caused them to gain weight.

A good compromise for most Americans seems to be a diet that obtains 50% to 55% of its calories from carbohydrate, 20% from lean protein and 25% to 30% of its calories from fat. Such a diet will keep you satisfied, and provides ample nutrients.

Although no one food or food combination is necessary for good health, scientists have found that eating meals or snacks that provide a balanced amount of carbohydrate, protein, and/or fat can help control weight by quelling hunger, and have the added benefit of keeping people energized by stabilizing their blood glucose levels. Eating a piece of fruit, a handful of crackers, or a bagel will cause a relatively rapid, but short-lived rise in blood sugar. Instead, combine the fruit with 8 ounces of low-fat or non-fat yogurt, or drink a glass of milk or add cheese slices to your cracker or bagel. (Additional snack ideas are listed below). The protein or fat will help to slow digestion thereby mediating the raise in blood sugar. Blood sugar at the upper or lower levels of the normal range can leave you feeling groggy. Keeping blood sugar in the mid-normal range provides an optimal amount of energy, and stabilizes the level of brain serotonin. (Serotonin is a neurotransmitter involved in appetite control. For more information see the box, "The Food/Mood Connection.")

Additional snack options: Make your own trail mix with 1.5 ounces of nuts & 1 ounce each of dried fruit and mini-pretzels. Cut a banana in half length-wise and spread it with peanut butter. Top half a bagel with low-fat cream cheese. Top 4 oz. of frozen non-fat yogurt with fresh fruit. Eat half of a sport nutrition bar (e.g. PowerBar(®).

THE FOOD/MOOD CONNECTION Ruth Clements, M.S., a nutrition instructor at the McLaren Hospital Optifast Weight Management Clinic in Flint, Michigan, has taught hundreds of formerly obese individuals to manage their weight and their moods by managing their blood sugar and brain serotonin levels. Her advice works just as well for people who are satisfied with their weight, but want to feel healthier. According to Ms. Clements, there is a direct connection between blood sugar, brain serotonin, and weight control. Serotonin is a neurotransmitter that to some extent controls appetite and mood swings. Brain serotonin levels parallel blood sugar levels. When blood sugar is low so is serotonin. A low serotonin level is linked to depression and low self-esteem. It also stimulates cravings for high sugar foods, which in turn leads to bingeing and weight gain. By eating a balanced combination of protein and carbohydrate at 3 to 4 hour intervals you can sustain optimal blood sugar and serotonin levels, which will help you make wise food and activity choices.