How much you should eat.

How much you should eat. The USDA new food pyramid often serves as a general guideline to healthy eating. The 2005 Dietary Guidelines for Americans outlines the following:

Fruit group: 2 cups (4 servings)

Vegetable group: 2.5 cups (5 servings)
Dark green vegetables: 3 cups/week
Orange vegetables: 2 cups/week
Legumes (dry beans): 3 cups/week
Starchy vegetables: 3 cups/week
Other vegetables: 6.5 cups/week

Grain group: 6 ounce-equivalents
Whole grains: 3 ounce-equivalents
Other grains: 3 ounce-equivalents

Meat and beans group: 5.5 ounce-equivalents

Milk group: 3 cups

Oils: 24 grams (6 teaspoons)

“Other” calorie allowance: 267 calories

As far as serving sizes go:

Fruit: about the size of your fist
1 piece of fresh fruit, 1/2 cup of chopped fruit, 3/4 cup of fruit juice, 1/4 cup dried fruit

Vegetables: about the size of your fist
Sample: 1/2 cup of cooked or cut-up raw veggies, 1 cup raw leafy veggies

Grains
Sample: 1 slice of whole-grain bread, 1 ounce of prepared cereal, 1/2 cup of pasta or rice, 1 computer-mouse-size baked potato, one CD-size pancake or waffle

Meat: about the size of a deck of cards
Sample: 2 to 3 ounces of meat, such as one chicken breast, 1/4-pound hamburger patty, medium pork chop
Other proteins: 1 tablespoon of nut butter, 1 egg, 1/3 cup of dry beans

Milk
1 cup of milk, 1 1/2 ounces of cheese (the size of 6 dice)

In general, a serving of snacks (like pretzels) can be measured as a rounded handful, says Todd.

What about fat? Many nutritionists also point to the Harvard Healthy Eating Pyramid as a reference, which places a stronger emphasis on exercise, whole grains, and healthy plant oils, such as those from nuts and avocados.

“The key to a healthy diet is to substitute good fats for bad fats — and to avoid trans fats,” adds Todd. This means replacing saturated and trans fats — the hamburgers, French fries, and buttery foods that increase the risk of certain diseases — with the healthy fats such as those found in avocados, fatty fish, olive and canola oil, soybeans, and nuts.

The USDA suggests total fat intake be limited to between 20 and 35 percent of daily calories, with less than 10 percent of calories coming from saturated fat. Other studies, like those focused on the Mediterranean diet, are finding that higher quantities of “good fats” (the unsaturated kind) may be healthier for our hearts, says Todd.