Many people these days are singing the praises of protein: Eat more for energy! Eat it to lose weight! But in fact, most of us already consume too much, say experts. Although we all need some protein -- which is a building block for everything from blood cells to hair -- the body can't store it. So any excess is converted to fat, a process that puts extra demands on the liver and kidneys. Plus, some research suggests that a protein surplus causes the body to lose calcium, upping the risk of osteoporosis.
How much protein do you need? Most adults should get 11 grams for every 30 pounds of body weight. (A woman who weighs 150 pounds, for example, needs 55 grams of protein a day.) But pregnant women need an additional 10 grams per day, and kids between the ages of 1 and 14 should have an extra gram per 2 pounds of body weight. (A 40-pound preschooler should get approximately 35 grams a day.)
Although many sources of protein pack a lot of fat (a 4-ounce hamburger has 28 grams of protein and 21 grams of fat, and 1 1/2 ounces of cheese provides 11 grams of protein and 14 grams of fat), not all do. See the list, below, for some leaner sources, all with under 5 grams of fat.
8 oz. low-fat cottage cheese 28 g
3 oz. roasted chicken breast 26 g
3 oz. tuna (canned) 25 g
3 oz. turkey (white meat) 25 g
3 oz. trout 23 g
3 oz. shrimp 18 g
1 cup kidney beans 14 g
8 oz. yogurt 11 g
11/2 oz. low-fat cheese 11 g
1 cup low-fat milk 8 g