Along with protein and carbs, fats are an important component of a good nutrition program. They contain more than twice the number of calories per gram as carbohydrates and proteins, so a small amount of fat contributes a large amount of calories. However, fats can certainly add flavor to food — and you need some healthy fat in your diet to maintain good health, a healthy weight, and normal physiological functions.
Some healthy oils, such as olive and canola oils, are terrific sources of monounsaturated fats, which have been shown to lower cholesterol levels, reduce high blood pressure, and lower the risk for type 2 diabetes. These oils are also rich in vitamin E, an antioxidant that helps keep your skin beautiful and may help protect your eyesight.
Canola oil, as well as walnut and flaxseed oils, provides omega-3 fatty acids, a type of fat that is known to reduce arthritis pain, decrease triglycerides, and improve cholesterol levels. Omega-3s can also help reduce the frequency and severity of migraine headaches, help protect skin from sun damage, and slow memory decline.
Saturated fats are found in few vegetable oils (palm oil and palm kernel oil are two you’ll see listed in packaged foods), but they are found in many spreads and condiments, including butter, lard, cream cheese, shortening, and cream- or cheese-based salad dressings, as well as the skin on poultry, and in certain cuts of meat. While saturated fats have been thought in the past to contribute to heart disease, as well as inflammation that can make other conditions worse, recent information has made this issue less clear cut. So, although the jury is still out on whether saturated fats are really as bad as they were previously made out to be, it's important to not go "butter crazy" and still practice moderation until more research is done.
Trans fats are far and away the worst type of fat. Although meats and dairy products contain trace amounts of naturally-occurring trans fat, the large majority of trans fats in the US diet are man-made. These man-made trans fats are produced by adding hydrogen to vegetable oils and used in some baked goods and deep-fryer oils to extend shelf life. Trans fats raise your bad (LDL) cholesterol and lower your good (HDL) cholesterol, so they increase your risk of heart disease even more than saturated fats. They also raise your risk of type 2 diabetes and increase inflammation, which can worsen arthritis pain. Stick margarine typically contains trans fats and should therefore be avoided. However, many brands of soft tub margarine are now trans-fat free. To identify healthy spreads, make sure the label specifies 0 g trans fat and the ingredients panel does not list any hydrogenated oils.
Other spreads include sterol and stanol spreads. Sterols and stanols are natural substances found in small amounts in the cell membranes of certain plants. Sterols and stanols have a structure similar to cholesterol. These compounds compete with cholesterol for access to receptors in the digestive tract, effectively blocking the absorption of dietary cholesterol and ultimately leading to lower blood cholesterol levels. Because you can’t get therapeutic doses from food alone, manufacturers have added concentrated amounts of sterols and stanols to certain heart-healthy spreads that taste and cook just like margarine. These spreads should be used only by people with cholesterol problems, who should consume no more than the recommended amount: two to three tablespoons per day. I suggest trying the light versions of these spreads to save calories.
The best oils and fats are olive oil, canola oil, walnut oil, soft tub margarine (trans fat-free), and sterol/stanol spreads.