Fat is an important part of a healthy diet. There's more and more evidence that many fats are good for us and actually reduce the risk of heart attack and stroke. They also help our sugar and insulin metabolism and therefore contribute to our goals of long-term weight loss and weight maintenance. And because good fats make foods taste better, they help us enjoy the journey to a healthier lifestyle. But not all fats are created equal--there are good fats and bad fats.
"Good" fats include monounsaturated fats, found in olive and canola oils, peanuts and other nuts, peanut butter, and avocados. Monounsaturated fats lower total and "bad" LDL cholesterol - which accumulates in and clogs artery walls--while maintaining levels of "good" HDL cholesterol, which carries cholesterol from artery walls and delivers it to the liver for disposal.
Omega-3 fatty acids - polyunsaturated fats found in coldwater fish, canola oil, flaxseeds, walnuts, almonds, and macadamia nuts--also count as good fat. Recent studies have shown that populations that eat more omega-3s, such as Eskimos (whose diets are heavy on fish), have fewer serious health problems such as heart disease and diabetes. There is evidence that omega-3 oils help prevent or treat depression, arthritis, asthma, and colitis and help prevent cardiovascular deaths. You'll eat both monounsaturated fats and omega-3s in abundance in all three phases of the diet.
"Bad" fats include saturated fats - the heart-clogging kind found in butter, fatty red meats, and full-fat dairy products. "Very bad" fats are the manmade trans fats. Trans fats, which are created when hydrogen gas reacts with oil, are found in many packaged foods, including margarine, cookies, cakes, cake icings, doughnuts, and potato chips. Trans fats are worse than saturated fats; they are bad for our blood vessels, nervous systems, and waistline.
Just recently, the FDA ruled that by 2007, food manufacturers must list the amount of trans fats in their products on the label. (The natural trans fats in meat and milk, which act very differently in the body than the manmade kind, will not require labeling.)