We all know what we should eat, many of us just eat a lot more of it than we should. It’s not hard to eat more than the daily recommended serving of some foods, even in one sitting. Recent surveys showed restaurants across the nation often serve three to five times the recommended daily serving of meat.

But exactly how much is a serving?

Extension Nutritionist Dr. Barbara Struempler says as food servings have increased in recent years, so has the public’s perception of what a serving should be. "We have really learned to like ‘Deluxe,’ ‘Super,’ and ‘Whopper’ – and we get it," she says. "When you go to a fast food place and order a No. 3, you can pay an extra 39 cents and get an extra, extra large fry and 64-ounce soft drink. The serving sizes are so huge."

Those huge portions mean more calories and often, excess weight.

"Years ago, a muffin was about one ounce," she says. "Now they are 5 ounces or larger. Several years ago a muffin had only 50 calories; today it can have over 500 calories. Very few adults need more than 2,000 calories a day, so if you get 500 calories from one muffin, that’s a significant part of your calories for the day. Not many people can do that."

According to the food guide pyramid, people should consume about two servings of protein each day. A serving of protein could be 3 ounces of poultry, fish or a lean meat (including beef, lamb and pork); two tablespoons of peanut butter; or one cup of legumes.

Struempler says a 3-ounce portion of meat is about the size of a deck of playing cards. "And you really don’t need more than about 5 ounces a day," she says.

A hamburger, two thin slices of roast beef, three-fourths cup flaked fish or half a chicken breast are all about 3 ounces, or one serving, of meat.

At least five servings of fruits and vegetables are recommended each day. A serving is half a cup of cooked or raw veggies, and 3/4 cup of fruit juice or one medium-sized piece of fruit.

Asparagus, broccoli, tomatoes, berries, cantaloupe, grapefruit, mango, orange, papaya, strawberries and tangerines are excellent sources of vitamin C.

Good sources of vitamin A include broccoli, carrots, sweet potatoes, leafy greens, kale, peas, spinach, string beans, winter squash and yellow corn.

Six servings of breads, cereals and starchy foods are recommended. A serving from this group would be a slice of whole-grain bread, half a cup of cooked cereal, one cup of flaked cereal, one cup of pasta or rice, three cups of popcorn or six saltine crackers.

"People think, ‘At least six servings, oh my, that’s a lot!’ But it isn’t. If you eat a hamburger, you’re getting two servings of your grains; each half of the bun is a serving. If you eat four or five saltines, that’s a serving of food. A serving of rice is about the size of a tennis ball. That’s not a lot. So most people eat a lot more than what they need."

For adults, 2 to 3 servings of dairy products are recommended. Children, teens and pregnant or nursing mothers need 3 to 4 servings. One serving from this group would be a cup of skim milk, a cup of nonfat or low-fat yogurt, half a cup or one cup of cottage cheese, 1 ounce of low-fat cheese or half a cup of ice cream.

Fats should always be limited, especially for weight control. Suggested serving sizes include 1 teaspoon oil, 1 teaspoon margarine, 2 teaspoons no-fat or low-fat mayonnaise, 2 teaspoons no-fat or low-fat mayonnaise-type salad dressing, 2 teaspoons sunflower or pumpkin seeds or 1 tablespoon of nuts.

A matchbook is about the size of a tablespoon of regular salad dressing or mayonnaise, Struempler says. "And that’s about 100 calories, so you have to really watch that."

Eating too much of even low-fat foods can still pack on pounds. Watch what and how much you’re eating. Decreasing your food intake to the recommended daily servings should help you lose pounds and maintain a healthy weight.