New Survey Shows Americans Ignore Importance of Portion Size in Managing Weight

American Institute for Cancer Research
Friday, 24 March 2000

Most Americans believe the kind of food they eat is more important for managing weight than the amount of food they eat, according to a new survey commissioned by the American Institute for Cancer Research (AICR). In the survey, a surprising 78 percent of respondents said that eating certain types of food while avoiding others was more central to their weight management efforts than eating less food.

This finding troubles nutrition experts, who have long suspected that messages about "low-fat" eating may cause the public to lose sight of a more pressing concern: total calorie intake. They stressed that effective weight management strategies place equal focus on both the kind and amount of food consumed. They added, however, that there is an increasing American trend to ignore the issue of portion size.

Indeed, the AICR survey suggests that Americans are seizing on 'quick-fix' strategies with little regard for how much food they actually consume. "People are eating more and wondering why they're getting fatter, " said Melanie Polk, M.M.Sc., R.D., Director of Nutrition Education at the Institute. "One big reason is that their focus is too narrow."

Americans, she said, are concentrating too exclusively on cutting fat, or going on fad diets that restrict carbohydrates, sugar, or some other factor. Too often, such strategies fail to address the larger picture of total calories consumed, not to mention good nutrition.

Portion Size Linked to Weight Management

Almost 62 percent of those responding to the AICR survey said they were currently above their ideal weight. Half of those who were above their ideal weight said they needed to lose six to 20 pounds, and another 13 percent said they needed to lose 21 to 30 pounds. Ten percent of those who said they were above their ideal weight reported being over by 50 pounds or more.

These numbers are in accordance with recent figures from the National Institutes of Health attesting that for the first time in history, the majority of Americans - an estimated 55 percent - are clinically overweight , while one in every four Americans is obese (severely overweight). This means that most Americans are now at increased risk for obesity-related diseases like cancer, coronary heart disease, stroke, diabetes, high blood pressure, gallbladder disease and osteoarthritis.

Anecdotal evidence from several sources illustrates the steady increase in U.S. portion sizes over the past few decades. Foreigners coming to this country express amazement at the amount of food served up in American homes and eateries. Foods adopted from foreign countries like croissants and bagels have grown to double or triple their original size, and the native muffin has ballooned from a standard ounce-and-half to as much as eight ounces today.

Meanwhile, fast food outlets feature gigantic "value meals" and "supersizes." Even table-service restaurants have swapped 10 -inch plates (once the industry standard) for 12-inch sizes.

USDA statistics show that American total daily caloric intake has risen from 1,854 kcal to 2,002 kcal over the last 20 years. That significant increase - 148 calories per day - theoretically works out to an extra 15 pounds every year. (Ironically, the same studies show that the average American has lowered the percentage of fat in his or her diet from 40 percent to 33 percent over the same amount of time.)

According to the AICR survey, however, most Americans are unaware that portions they consume have increased in size. Six in ten (62 percent) of survey respondents said that the portions served in restaurants are the same size or smaller compared to 10 years ago. Eight in ten said the portions they eat at home are the same or smaller. Americans under 35 years of age were more likely to recognize that their food portions have grown compared to baby-boomers aged 35 to 54 and Americans 55 or older.

Spurred by results of the survey, AICR hopes to raise awareness about the importance of portion size to weight management. They encourage Americans to develop a common-sense mental gauge for how much is too much. Experts have found that a working knowledge of standardized serving sizes is often helpful for this purpose, but the AICR survey reveals that few Americans understand this basic nutritional concept.

Broad Ignorance of Serving Sizes

Respondents to the AICR survey were asked to estimate the standard servings defined by the USDA Food Pyramid for eight different foods, including pasta, green salad, beans and mashed potatoes.

Only 1 percent of respondents correctly answered all eight serving-size questions, while 63 percent missed five or more. A remarkable 31 percent managed to estimate only one serving size correctly.

"These are distressing numbers," said Polk. "They suggest that an important message about portion control isn't getting through." Experts say the concept of standard serving size is fundamental to everyday nutrition and weight management. Standardized serving sizes help consumers, health professionals and food manufacturers find a common language for easier communication.

Polk added, however, that the standard serving size of a food should not be regarded as its "recommended amount." A serving size is simply the unit of measure used to derive nutritional information like calories, fat, cholesterol, carbohydrates, protein, vitamins and minerals.

"Serving sizes may be standardized, but individual portions can and do differ, because different people have different caloric needs," Polk said. Portion size also depends upon an individual's weight management goals.

For example, an inactive person may require only one cup of cereal in the morning, which is the standard serving size for many varieties.

Someone who runs five miles every day, however, may need two or possibly even three standard servings of the same cereal to get the calories he or she requires. In that case, those three servings would be an appropriate portion.

"It's easy for people to get an idea of how many standard servings go into their personal portions," said Polk. AICR recommends that people begin by taking a day to learn what a standard serving really looks like. Measuring out Food Pyramid serving sizes or those listed on the Nutrition Facts food label is a good way to "eyeball" some favorite foods.

Individuals should make a mental note of what one serving looks like on a plate. This "eyeball" method develops a feel for single servings that, in turn, provides a clearer sense of how much food is actually being consumed at any given meal.

Yet even among those survey respondents who displayed considerable knowledge about proper portions (i.e., the 14 percent who could correctly estimate six or more serving sizes), the vast majority (86 percent) said they "seldom or never" measure out their food. At a time when obesity statistics continue to climb despite a greater than ever public awareness about dietary and fitness issues, AICR stressed the importance of putting knowledge about portion size into everyday use. (See AICR Tips for Getting Perspective on Portions, below.)

"It's no good knowing that your plate's too full and cleaning it anyway," said Polk. "As soon as you've had enough, say 'when' and refrigerate the leftovers."

She added that knowing when you've had enough can be difficult if you judge by appetite alone. It takes about 10 minutes for the stomach to signal the brain that it is full. Instead of waiting for a feeling of satiety, AICR recommends learning your personal portions and limiting the amount of food you take in the first place.

Additional Findings of the AICR Survey

Only 12 percent of Americans said they refer to Nutrition Facts food labels for help determining their personal portion size. Of this small number, women are twice as likely as men to use food labels as a reference.

Instead, most Americans (56 percent) said that how hungry they are determines the size of the portions they eat. One in four Americans (26 percent) belongs to the "Clean Plate" club, saying that the amount of food they consume depends upon how much food they are served.

Another one-third (34 percent) cite the amount of food they are used to eating. This passive approach to portions is much more prevalent among Americans 30 pounds or more above their ideal weight than among Americans at their ideal weight. This finding may in part be due to the fact that calorie needs decrease with age. A 50-year-old consuming the same amount of food he or she ate at age 30 is more likely to be overweight.

Women consistently displayed more nutritional knowledge than men, and were better able to correctly identify serving sizes for many foods, including green beans, canned beans, raisins and green salad. For example, 36 percent of women and 26 percent of men knew the correct serving size for pasta. Fifty-seven percent of women and 51 percent of men correctly identified the serving size for canned beans.

Interestingly, however, men were better able to estimate the serving size for one of the eight foods they were asked about: breakfast cereal. Fifty-four percent of men knew the correct serving size for breakfast cereal, compared to 49 percent of women. Both men and women tended to overestimate the correct serving sizes for many foods. Fifty-nine percent of those who were unable to identify the serving size for pasta chose a size that was larger.

Overweight individuals showed a slightly better sense of serving sizes than the rest of the population. For example, 38 percent of those who were 30 pounds or more overweight correctly estimated the proper serving size for pasta, compared to 27 percent of those at or less than 10 pounds over their ideal weight.

Conducted for AICR by Penn, Schoen and Berland Associates, the survey involved 1,003 Americans aged 18 and older, chosen at random. Respondents were interviewed by telephone in late February, 2000.

AICR Tips for Getting Perspective on Portions

At home:

Take a day to "eyeball" the serving sizes of your favorite foods. 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 weight, gain weight, or maintain your current 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.

At 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.

For more information, or to contact American Institute for Cancer Research, see their website at:

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