For years fat was a dirty word, something experts warned would harm our hearts as well as our waistlines. Then we were told we could eat as much of it as we wanted—as long as we avoided the bread basket.

Fortunately, researchers have now singled out what kinds of fat you should eat and how much you need every day. To make it simple, we've boiled it all down to these six facts.

1. Fat won't make you fat

You may think any fat you consume will go straight from your lips to your hips, but that's not entirely accurate. Any nutrient, whether it's a fat, carbohydrate, or protein, will be converted into body fat if you eat too much of it. While fat does pack more than double the calories per gram of protein and carbs (9 versus 4), including a reasonable amount of it in your diet won't derail your weightloss efforts. In fact, upping your fat intake may actually help you slim down: Researchers at Stanford University found that people who ate a moderate-fat diet lost twice as much weight in two months as those who followed a lowfat plan.

2. Your body needs it

A steady diet of skinless chicken breasts and hold the- dressing salads isn't just bland, it's also downright dangerous. The human body cannot survive without fat. In addition to acting as an energy source it provides a protective cushion for your bones and organs and keeps your hair and skin healthy.

What's more, fat helps your body absorb certain vitamins, such as A, D, E, and K, from all the healthy fare you so dutifully pile on your plate. These nutrients do everything from fortify your bones to protect against heart disease. According to a recent study from Ohio State University, people who ate salsa made with avocado (which is rich in healthy fat) absorbed four times more of the antioxidant lycopene and nearly three times more vitamin A from tomatoes than those who noshed on nonfat salsa.