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Why Portion Sizes Are Important

You've heard the news that much of America -- including its kids -- is overweight or obese. If you are in that crowd and want to lose the extra pounds, the first step is to know what and how much you're eating.

One large obstacle is that most people are serving-size challenged, thanks to today's large portions: mega-muffins, heaping plates of pasta, behemoth burgers and extra-large bagels.

According the National Heart, Lung and Blood Institute (NHLBI), a "portion" can be thought of as the amount of a specific food you choose to eat. Portions can be bigger or smaller than the recommended food servings. A "serving" is a unit of measure used to describe the amount of food recommended from each food group. For example, a recommended serving of whole grains would be one slice of bread or a half cup of rice or pasta. Current recommendations are for 6 to 11 servings of whole grains a day.

"We consume much more than we think we do," says Edgar Chambers IV, Ph.D., professor of human nutrition at Kansas State University. "This is especially true with condiments, such as salad dressing and butter; foods eaten one at a time, such as french fries; and foods spread out on plates, such as pasta."

Expanding waist lines

About two-thirds of adult Americans are overweight or obese, and about 16 percent of children and adolescents ages 6 to 19 years also are overweight, according to the NHLBI and the Centers for Disease Control and Prevention (CDC).

The CDC says that behavior and genetics contribute to this problem. Your genes influence how your body burns calories for energy and how it stores fat. Your behavior -- the amount of food consumed and the amount of daily activity -- determines if you will gain weight. Your cultural attitude, financial situation and environmental factors, as well as your individual characteristics influence how much you eat and exercise.  

Every day, your body uses calories to perform activities such as breathing, digestion and moving around. If you eat more calories than needed for these activities, the extra calories are stored as fat. For an average adult, this means that eating 100 more calories a day causes a weight gain of about 1 pound in a month. Regular physical activity will burn excess calories and prevent weight gain.

If you need to lose weight, try reducing your daily calories by 500, so that you can lose one pound per week. You can do this by eating 250 calories less per day and exercising enough to burn 250 calories. To better control your calorie intake, you need to know what and how much you're eating.

Measure the food, if you can

Measure your food with measuring cups and spoons and keep a food diary, comparing your typical servings (and calories) with the standard serving sizes listed on food labels. In a study Dr. Chambers published in the Journal of the American Dietetic Association, he found those who pre-measured their food were the most accurate judges of standard portion sizes.

"Measuring can really help you see what three ounces of deli meat looks like," says Dr. Chambers. Sound like a lot of work? Don't worry -- you don't have to keep at it. After a week of measuring and comparing, you'll have a solid sense of what a half-cup of cereal or a teaspoon of mayonnaise looks like. With french fries, potato chips, M and Ms and other hand-to-mouth, tough-to-measure foods, count out a serving beforehand. If your diet allows you eight french fries, eat no more than that.

Determine portions in other ways

If you're not up to retrieving measuring tools, make do with what you have handy, such as your hands.

"The palm of your hand is the right amount for meat, chicken or fish," says Kathleen Johnson, M.S., R.D., a consulting nutritionist in Arizona. With peanut butter, a standard serving is about the size of a ping pong ball, or two tablespoons. A standard serving of ketchup or low-fat or nonfat salad dressing is the size of an Oreo. An appropriate amount of cooked rice or pasta -- not the double portion restaurants typically serve -- equals the size of one-half of a baseball, or half a cup. So does a serving of vegetables, with the exception of mashed potatoes, a normal amount of which resembles an ice-cream scoop. For potato chips, aim for the amount in those tiny bags that go in kids' lunch boxes.

For more information on how to judge portion sizes, go to the NHLBI website.

Curb liquid calories

"The appropriate portion size for coffee drinks, regular sodas and smoothies is a container the size of a coffee cup," says Ms. Johnson. With today's big-slurp containers, it's easy to guzzle more than you think. And, the liquid sugar in soda slides down effortlessly, loading us with empty calories that don't fill us up, as researchers at Purdue University in West Lafayette, Ind., discovered. They found that people who added equal amounts of calories -- 450 calories per day for four weeks -- either in the form of soda or jelly beans gained weight only on the soda, suggesting that sugary liquids may encourage weight gain more than solid sweets.

If you're a regular "popaholic," consider switching to diet soda or ordering the small, kid-sized regular soda in restaurants. Also, bypass the soda machine occasionally and get more water in your diet by switching to diluted juices -- mix water or sparkling water with your favorite juice, preferably one that's calcium-fortified. Low-fat or nonfat milk is a good alternative because it provides calcium and other nutrition instead of the “empty calories” of sodas and juices.

Eat only half the entree

"The average restaurant entree has about twice the number of calories most adults need in one meal," says Ms. Johnson.

Eat only until you feel full, then stop. To avoid overeating, share your entree or order a half portion. Or, ask for a take-home container as soon as the waiter serves your meal, then wrap up half before you dig in. Or, "order just a salad with low-fat dressing and a low-calorie appetizer as your meal. For most of us, that's the right amount of food," Ms. Johnson says.

Cook in batches

At home, prepare recipes for exactly the number of people who will be eating by amending recipes accordingly. Or, if you're cooking for one or two, go ahead and make a typical "serves six" recipe. Then divvy up one or two portions and put everything else away before eating so you won't be tempted to finish it. Freeze the rest in single-serving sizes for subsequent meals.

Make it satisfying

Standard serving sizes can seem small; the official serving size for ice cream, for example, is only one-half cup. What if you feel like having one or two cups? Go ahead, but keep portion sizes in mind and adjust your day's calories accordingly by eating less at your next meal. "At least, you know you're eating two cups instead of guessing," says Dr. Chambers.

On the other hand, less can be more if you play this mealtime mind game: To make the most of the right-sized portion of anything, put one standard serving in a dish or on a plate. Whatever you do, don't eat straight out of the carton -- it's too easy to keep going. "Then sit down and focus on your food, savoring the eating experience," says Dr. Chambers.

"One of the worst things we do is eat while we're doing something else, like watching TV, driving or talking on the phone," he says. "But if you truly enjoy your food while you're eating it, you'll probably get by on a lot less."

Food for thought

To plan a healthy diet, follow the 2005 U.S. Department of Agriculture (USDA) Dietary Guidelines. In these guidelines, the number of servings of each food group you should have is based on the number of calories you need for your age, gender and activity level, Visit the USDA's website to learn how many calories and serving you need each day.