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), many Americans 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.
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.
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.
What is a portion size? According to the American Dietetic Association, you can use the following "models" to approximate portion sizes:
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.
Healthier US.gov
Canada's Food Guide
Dietitians of Canada
American Institute for Cancer Research website. Available at: http://www.aicr.org/.
American Dietetic Association website. Available at: http://www.eatright.org/.
Last reviewed February 2011 by Brian Randall, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.