Add fish to your weight loss regimen. Overweight people who are on a weight loss diet may be able to reduce their risk of cardiovascular disease and diabetes by eating fatty fish such as salmon, tuna, cod and mackerel every day, according to a study in the November 1999 issue of the American Journal of Clinical Nutrition. Fatty fish are rich in omega-3 fatty acids, which have been shown to protect against heart disease by lowering cholesterol levels and reducing high blood pressure.