All Fats Are Not the Same
Fat is an essential nutrient for the body. Our bodies need a certain amount of fat to function properly. For example, we need fat to absorb vitamins A, D, E and K. Some types of fats, such as saturated and trans fats, are considered to be less healthful, and intake of these should be kept low. Other kinds of fats are considered "better for you" and are found mostly in plant foods (such as vegetable oils, nuts, fish and avocados). Remember that any type of fat can supply excess calories, which is why keeping intake of dietary fat within recommended levels is a key part of healthy eating. Here's a breakdown of the different kinds of fats, and some foods where you'll find them.
Saturated fats can increase the "bad" blood cholesterol levels, which is a risk factor for heart disease. This kind of fat is found in animal products, such as meat (sausage, ground beef, spareribs), poultry (especially dark meat and skins) and dairy foods (whole milk, cheese, ice cream), as well as palm and coconut oils. Experts advise us to consume diets low in saturated fat (less than 10% of total calories).
Trans fats are made by converting liquid fat to solid fat in a process called hydrogenation. This helps to lengthen products' shelf life. Trans fats can result in elevated blood LDL cholesterol ("bad" cholesterol) levels. According to the National Academy of Sciences, some evidence also suggests that intake of trans fat lowers HDL cholesterol ("good" cholesterol). HDLs are high-density lipoproteins, which help to remove cholesterol from our bodies. LDLs are low-density lipoproteins, which add cholesterol to our bodies. Since 2006, the FDA has required that food companies list the amount of trans fats specifically on food labels. Trans fats tend to appear in the ingredient statement of food labels as hydrogenated or partially hydrogenated oils.
Unsaturated fats include polyunsaturated or monounsaturated fats. Polyunsaturated fats have been shown to lower total cholesterol and LDL ("bad") cholesterol, but they may also lower HDL ("good") cholesterol. Food sources of polyunsaturated fat include soybean, corn, sesame and sunflower oils, as well as most fish. The monounsaturated fats lower total cholesterol and LDL, but maintain good HDL cholesterol. Up to 20% of your daily calories can come from monounsaturated fats. Dietary sources include nuts, olive oil, canola oil and avocados.
Most nuts—including peanuts, almonds, pecans and hazelnuts—contain monounsaturated fats and no trans fat. In July 2003, the U.S. Food and Drug Administration indicated that it would allow companies to place the following qualified health claim about nuts and the reduced risk of coronary heart disease on the label of whole or chopped peanuts, almonds, hazelnuts, pecans, pistachios and walnuts: Scientific evidence suggests but does not prove that eating 1.5 ounces per day of most nuts [such as almonds, hazelnuts, peanuts, pecans, pistachios and walnuts] as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease. See nutrition information for fat content. (FDA, 2003).
Of course, the overall amount of fat in most people's diets shouldn't exceed 30-35% of total calories. So unsaturated fats should replace saturated and trans fats in your diet—not simply be eaten in addition to them. It is also important to watch overall caloric intake when substituting unsaturated fats for trans and saturated fats.
Consider these simple and delicious ways to substitute unsaturated fats for saturated and trans fats in your daily diet:
- At least once or twice a week, skip meat or poultry for dinner and enjoy foods that provide vegetable protein, such as beans, legumes and soy-based products.
- Sprinkle your salad with slivered almonds and drizzle with walnut oil and balsamic vinegar.
- Sauté vegetables in canola oil or olive oil instead of butter.
- Try soy or nut butters (such as peanut, cashew or almond butters) instead of regular butter on your toast.
- When eating out, avoid cream sauces and choose dishes prepared with olive oil.
- Qualified Health Claims: Letter of Enforcement Discretion—Nuts and Coronary Heart Disease (Docket No 02P-0505). United States Food and Drug Administration. Center for Food Safety and Applied Nutrition. Available at: http://www.cfsan.fda.gov/~dms/qhcnuts2.html. Accessed October 9, 2004.
- National Cholesterol Education Program ATP IDietary Guidelines for Americans, 2005.