Avocados
Nutrients: Vitamins A and C, folate, potassium
How they help control weight: Although this fruit is calorie-dense, it is a good option for satisfying fat cravings because about 16 percent of its total weight is fat—the better monounsaturated kind.
Serving size: About half of an avocado
Notes: The oils in avocados—oleic acid and linoleic acid—may help control cholesterol levels. Aside from the usual guacamole, you can chop avocados as a garnish for chili or black bean soup or use avocado to make a creamy salad dressing.

Olive oil
Nutrients: Vitamin E, iron
How it helps control weight: Because olive oil's predominantly monounsaturated fatty acids benefit the heart, it is an excellent replacement for other cooking oils.
Serving size: 2 tablespoons
Notes: In November 2004, the Food and Drug Administration approved a qualified health claim for olive oil labels and advertising, allowing manufacturers to state that a daily dose (2 tablespoons) of olive oil may reduce heart disease risk. Use olive oil in salad dressings and marinades. Drizzle over steamed vegetables before serving.

Salmon
Nutrients: Vitamins A and D, iron, calcium
How it helps control weight: Lower in fat than red meat, high in protein. Experts say meals satisfy you longer when you include a small portion of protein.
Serving size: 3–4 ounces
Notes: Although fish such as halibut and cod are lower in fat, salmon is rich in heart-healthy, mood-enhancing omega-3 fatty acids (also available in anchovies, bluefish, herring, mackerel, and sardines). Healthiest when it's wild (as opposed to farm-raised), and baked or grilled. Eat two or three times a week, if possible.

Walnuts
Nutrients: Vitamin E, folate, iron
How they help control weight: High-fat, high-fiber content provides satiety and energy in a very small amount.
Serving size: 1/4 cup
Notes: Protein-rich walnuts are full of omega-3 fatty acids, also abundant in almonds, Brazil nuts, peanuts, and pine nuts. Because walnuts are high in fat, enjoy a small portion as a snack or garnish on salads.

Sources: American Journal of Clinical Nutrition, 2005, vol. 81, no. 1; The Encyclopedia of Healing Foods by Michael Murray, ND, and Joseph Pizzorno, ND (Atria Books, 2005); The New Complete Book of Food by Carol Ann Rinzler (Checkmark, 1999).