I've outlined the basic principles of the diet below — follow these guidelines for just two weeks and you'll not only lose weight; you'll feel more energetic.

Have breakfast every day

Eating a healthy, nutrient-dense breakfast — one that includes protein, whole grains and fruit — will help keep your insulin level steady all morning and prevent you from overeating later on. The National Weight Control Registry, a study of nearly 4,000 dieters who have lost weight and kept it off for up to six years, found that those who ate breakfast daily lost more weight and kept the weight off longer than those who didn't eat upon rising. Two good choices: an egg sandwich with strawberries, or whole-grain cereal with low-fat milk and a banana.

Drink more water

Most of us don't realize how many calories we consume through sodas, juices, alcoholic drinks and other beverages. So I'd like you to try an experiment: Drink nothing except water and coffee for two weeks and just watch the pounds melt away. This includes diet soda. Research shows that diet sodas may increase the body's cravings for sugar-sweetened, high-calorie foods.

Get fishy

Fish is a crucial component of the AARP New American Diet. It has the good omega-3 fatty acids that you need for brain health, is low in calories and contains important nutrients. The omega-3s in fish may also lower your risk of getting certain cancers and may improve some inflammatory conditions, such as rheumatoid arthritis, the AARP-NIH study finds. Conversely, eating red and processed meats (think hot dogs and sausages) increases that risk, so eat fewer of them.

Fill up on fruits and veggies

Some fad diets foolishly discourage eating fruit, but the AARP-NIH study clearly shows that incorporating fruits and vegetables into your daily diet will help you live longer. Consuming these antioxidant-rich foods can also result in weight loss even when you're not trying to drop pounds, researchers at Penn State found.

Embrace whole grains

Whole grains are a major source of not only vitamins and minerals but also fiber, and the AARP-NIH study shows they have extraordinary health benefits as well. Regularly consuming whole grains — whole wheat bread, whole wheat pasta and brown rice — can cut your risk of heart disease, respiratory illness and some cancers, including colon and breast cancers. Plus, whole grains can help you lose weight, specifically belly fat that's linked to diabetes, hypertension and heart disease.

Next page: Be wary of "diet foods." »