Controlling Portion Sizes

Most people consume far more calories than they realize. The culprit? A warped sense of portion size.

According to a survey conducted by the American Institute for Cancer Research (AICR), most Americans (78%) still believe that the kind of food they eat is more important in managing their weight than the amount of food they eat.

"People are eating more and wondering why they're getting fatter," says Melanie Polk, MMSc, RD, director of Nutrition Education at the AICR. "One big reason is that their focus is too narrow." Ms. Polk adds that Americans are concentrating too much on cutting fat, or relying on fad diets that restrict carbohydrates, sugar, or some other nutrient. Studies reveal that these strategies fail to address the issue of total calories consumed, as well as overall good nutrition.

Respondents to the AICR survey were asked to estimate the standard servings defined by the USDA Food Guide Pyramid for eight different foods, including pasta, green salad, beans, and mashed potatoes. Only 1% of respondents correctly answered all eight serving-size questions, while 63% missed five or more. A notable 31% managed to estimate only one serving size correctly.

"These are distressing numbers," says Ms. Polk. "They suggest that an important message about portion control isn't getting through."

Serving Sizes Essential to Good Nutrition

Experts say that understanding the concept of standard serving sizes is essential to good nutrition. Standardized serving sizes help consumers, health professionals, and food manufacturers find a common language for the sake of communication.

Although serving sizes are "standardized," individual portion sizes will vary because people have different caloric requirements. Portion size also depends on a person's specific weight management goals and health needs. For example, pregnant and breastfeeding women may require larger portions of food than do women who are not pregnant or nursing.

Weight Management: The American Dilemma

The problems of obesity and lack of nutrition awareness also seem to have a cultural component. Take a look at fast food restaurants. Most of these restaurants offer "super-size" or "value" meals, which often contain an entire day's worth of calories and fat.

Statistics from the US Department of Agriculture suggest that Americans' total daily caloric intakes increased by 24.5%—about 530 calories—per day between 1970 and 2000. According to the USDA, people are also eating out or ordering take out more often than they used to.

Over the past 30 years there has been both a focus on low-fat and no-fat, leading to a temporary decline in fat consumption, and a focus on low-carbohydrate or low-sugar intake. During the fat-free era, Americans more than made up for their lower fat intakes with larger portion sizes of other types of foods. Larger portion sizes equal more calories. And more calories lead to weight gain, regardless of the source of the calories—fat, protein, or carbohydrate. Similarly, during the low-carb craze, people made up for the carbohydrates by eating more fat and protein.

Nutritional Needs Vary

Portion sizes and overall dietary requirements depend on several factors, including activity level. For example, an inactive person may only need three-quarters to one cup of cereal in the morning, which is the usual serving size of most varieties. But someone who runs several miles a day or who engages in other forms of aerobic exercise may need two or three standard serving sizes.

To help determine a standard serving size, Ms. Polk recommends measuring out Food Guide Pyramid serving sizes or those listed on the "Nutrition Facts" food label.

Ways to Estimate Portion Sizes

What's a portion size? According to the American Dietetic Association, you can use the following "models" to approximate portion sizes:

  • A deck of playing cards = one serving (3 ounces) of meat, poultry, or fish (can also use the palm of a woman's hand or a computer mouse)
  • Half a baseball = one serving (½ cup) of fruit, vegetables, pasta, or rice (can also use a small fist)
  • Your thumb = one serving (one ounce) of cheese
  • A small hand holding a tennis ball = one serving (one cup) of yogurt or chopped fresh greens
  • When at home:
    • Take time to "eyeball" the serving sizes of your favorite foods (using some of the models listed above).
    • Measure out single servings onto your plates and bowls, and remember what they look like. Figure out how many servings should make up your personal portion, depending upon whether you need to lose, gain, or maintain weight.
    • Avoid serving food "family style." Serve up plates with appropriate portions in the kitchen, and don't go back for seconds.
    • Never eat out of the bag or carton.
  • When in restaurants:
    • Ask for half or smaller portions. (Don't worry if it doesn't seem cost-effective; it's worth it.)
    • Eyeball your appropriate portion, set the rest aside, and ask for a doggie bag right away.
    • If you order dessert, share it or choose a healthier option like fruit.

Seek Dietary Guidance

If you are unsure about your personal nutrition requirements, go to MyPyramid to get eating recommendations based on factors, such as your age, sex, and activity level. For an even more individualized plan and for motivation, seek the advice of a registered dietitian (RD). These professionals can create individual menus and food plans that are suited to your specific weight management and overall health goals.