After so many years of being told otherwise, the idea that fat is good for you is hard to swallow, but true. Are you eating the right type of fat? There are good fats and bad fats to look for in your diet.
Fat Facts: What's Good About Fat
Fat is the target of much scorn, yet it serves up health benefits you can't live without.
Fat supplies essential fatty acids (EFAs). "Your body is incapable of producing the EFAs, known as linoleic acid and alpha-linolenic acid, so it must derive them from food," explains Wahida Karmally DrPH, RD, professor of nutrition at Columbia Universityand director of nutrition at The Irving Institute for Clinical and Translational Research.
In addition, fat ferries vitamins A, D, E, and K -- known as the fat-soluble vitamins -- into and around the body.
"Fat is also necessary for maintaining healthy skin, and it plays a central role in promoting proper eyesight and brain development in babies and children," Karmally tells WebMD.
For all the good it does, fat is often fingered as the culprit in the battle of the bulge. It's easy to understand why. At 9 calories per gram, any type of fat -- good or bad -- packs more than twice the calories of carbohydrate and protein.
Yet, it's a mistake to equate dietary fat with body fat. You can get fat eating carbs and protein, even if you eat little dietary fat.
"Excess calories from any source is what's responsible for weight gain, not fat per se," says Alice H. Lichtenstein, DSc, professor of nutrition at Tufts University and director of the Cardiovascular Nutrition Laboratory. "In the scheme of things, total calorie intake matters the most."
Fat Facts: What's Bad About Fat
There is a well-established link between fat intake and heart disease and stroke risk.
Diets rich in saturated fat and trans fat (both "bad" fats) raise blood cholesterol concentrations, contributing to clogged arteries that block the flow of oxygen-rich blood to the heart and brain.
But there's a caveat: Very low-fat diets -- 15% or 34 grams of fat in a 2,000-calorie diet -- may not reduce artery-clogging compounds in the bloodstream in everyone. Nor can most people maintain a very low-fat diet in the long run. The American Heart Association (AHA) recommends that we get 20% to 35% of our calories from fat. Most Americans get 34% or more.
When it comes to dietary fat, quantity and quality count.