1. Coconut Oil
Why it makes you skinny:
Most oils, including corn and olive, are broken down into fatty acids that circulate through your body after you eat them, allowing hungry fat cells to suck them up and store them. Coconut oil, however, is rich in a type of fat rarely found in other foods, called medium-chain triglycerides (MCTs). "When you eat MCTs, they go straight to the liver instead of going directly into circulation. There, they're burned up like kindling for a fire," says Cherie Calbom, author of The Coconut Diet.
Plus, your body requires extra energy to digest MCTs. Including them can increase your daily burn by 45 calories, says Marie-Pierre St-Onge, Ph.D., assistant professor of nutrition at the University of Alabama at Birmingham.
How to use it:
Spread coconut oil on toast instead of butter, melt it on veggies or use it for sautéing. But don't deep-fry with it; coconut oil breaks down at high temperatures. Look for virgin oil (nonvirgin is processed and tastes nasty) at health-food stores. Beware: Coconut oil is saturated and can raise cholesterol and triglycerides, so alternate it with other oils.
2. Enova
Why it makes you skinny:
Traditional fats contain three fatty acids, but Enova, an oil, has just two, so your body treats it differently. It's processed in much the same way as coconut oil, traveling directly to the liver, where it's burned off and used for energy.
When people on low-calorie diets consumed 15 percent of their daily calories from Enova (between three and eight teaspoons), they lost 1 percent more weight and nearly 3 percent more body fat than those who ate a similar amount of vegetable oil.
How to use it:
Enova's neutral taste makes it perfect for salad dressings. You can also bake and sauté with it, but don't use it for frying, says Kyle Shadix, R.D., of the Art Institute of New York City/New York Restaurant School, as it can change taste and color when overheated. One caveat: Enova is expensive — it costs about $6.65 for a 20-ounce bottle, compared to about $1.60 for the same size bottle of vegetable oil.
3. Nut Butters
Why they make you skinny:
Research has shown that people who eat nut butters often weigh less than those who shun them. It's likely that the combination of protein, fat and fiber keeps you full, so you'll eat less overall.
Whole nuts are effective, too: Purdue University researchers found that people who added peanuts to their diet for 19 weeks boosted the amount of calories they burned at rest by 11 percent. Why? The unsaturated fat in peanuts and nut butters burns faster than other fats.
How to use them:
Nut butters add flavor to Asian noodles, satays or dipping sauces, or you can use them as a spread for your morning muffin. Chunky varieties are better, since they have more fiber than creamy versions. But a little goes a long way, says New York-based nutritionist Bonnie Taub-Dix, R.D. "The ideal amount is one to two tablespoons, not the whole jar." Use natural versions that are free of added oils and hydrogenated fats.
When Good Fats Go Bad
All fats contain nine calories per gram. To get weight-loss benefits, you have to substitute these for fat that's already in your diet, not tack them onto what's on your plate.
