Let's face it, fat can be confusing. For years, experts have told us that fat is bad, and we must avoid it if we want to live long and healthy lives. Then, researchers discovered this isn't exactly true. Since then, many of us have either overindulged in unhealthy fats (or bad carbs) and found ourselves among the 66 percent of U.S. adults who are overweight, or we continue to eschew all fat in the mistaken belief that a low-fat diet is the secret to a thinner, healthier you. But the old adage “‘The less [fat] you eat the better’ is just not true,” says Karen Collins, a clinical dietitian and nutrition adviser to the American Institute for Cancer Research in Washington, D.C.
Here's what is true: Fat is an integral nutrient in your diet. It provides energy and essential fatty acids and helps your body absorb vitamins A, D, E, K and carotenoids. But all fats are not created equal. Some are beneficial to your health, others are not, and all are high in calories, so moderation is still key.
The Good Fats Healthy fats -- aka unsaturated fats -- can lower your risk of heart disease by decreasing your levels of "bad" LDL cholesterol, explains Dawn Jackson Blatner, a registered dietitian and spokesperson for the American Dietetic Association. "They may even raise your 'good' HDL cholesterol," she says.
Why is one cholesterol good and the other bad? LDL (or low-density lipoproteins) carry cholesterol from your liver to the rest of your body. If you have too much LDL cholesterol, it gets deposited in your artery walls, where it can increase your risk of angina (chest pain), heart attack or stroke -- hence its bad moniker. HDL (or high-density lipoproteins), on the other hand, carry cholesterol from the blood back to the liver, which helps eliminate it, thus, high levels of HDL is a good thing.
When choosing fats, unsaturated is the healthy way to go. These include:
Monounsaturated fat, which remains liquid at room temperature. Best sources are olives, olive oil, canola oil, peanut oil, sunflower seeds, avocados, cashews, almonds, peanuts and most other nuts.
Polyunsaturated fat, which is also liquid at room temperature and is found in safflower, corn, sunflower and soy oils.
Omega-3 fatty acids, which are polyunsaturated fats found mainly in seafood. Great sources are fatty, cold-water fish, like salmon, herring, mackerel, anchovies and sardines.
The Bad Fats
While good fats boost heart health, unhealthy fats -- that is, saturated and trans fats -- "increase bad [LDL] cholesterol levels and [raise] our risk for heart disease, the number one killer of men and women," explains Blatner. Here's where bad fats lurk:
Saturated fat, which is generally solid at room temperature, is most often found in animal products, like whole milk, ice cream, butter, cheese and red meat, plus a few plant products, such as coconut and palm oils.
Trans fats are the really bad fats. Not only do they increase LDL, but they decrease HDL and raise triglycerides, a type of fat in your bloodstream. Trans fats are made by adding hydrogen to vegetable oils in order to produce a solid fat that stays fresh longer on grocery store shelves. You will find them in many margarines, vegetable shortenings, fried foods (like doughnuts and french fries) and commercially baked goods, such as crackers, cookies, cakes and chips. The best way to tell if a food has trans fats is to read the ingredient list. If you see the word "hydrogenated," the product contains trans fats. Nutrition labels will also report trans fats, but if a product has less than 0.5 grams per serving, it will read as 0 grams. Finally, when eating out, keep in mind that many restaurants use trans fats for frying.
The Bottom Line The USDA recommends that you consume between 20 and 35 percent of your calories from fat, most of which should come from unsaturated fat sources. Saturated fats should be limited to 10 percent of total calories, and you should try to avoid trans fats completely. In other words, most 30-year-old women need around 2,000 calories a day. This adds up to between 44 and 78 grams of fat, no more than 20 of which should come from saturated fat. So go ahead and enjoy your meal. When you choose fats wisely, you can have your cake and eat it, too!
Nancy Gottesmanwas a senior editor at Shape magazine for 11 years. Since going freelance, she's been writing health and nutrition stories for publications such as O: The Oprah Magazine, Parents, Women's Health, Fit Pregnancy, Viv and Family Circle.
