Portion Distortion: How Big Is a Serving?

When it comes to losing weight and maintaining a healthy weight, eating the right foods is only half the story; the other half is eating the right amount. But how much food actually constitutes a healthy-sized portion? Nutritionists tell us the best way to determine the proper amount of food in a given serving is to look at the Nutrition Facts label and measure it out. And that may have been true in the early 1990s when the FDA first defined serving sizes, but not today. Over the past 20 years, average portion sizes of all foods, including hamburgers, French fries, soft drinks, and salty snacks have increased, in some cases by more than 50 percent. That means because the standard serving size shown on a package label determines all the other nutritional values, the calorie counts are often inaccurate—and thus, misleading.

In fact, a recent study by researchers at Tufts University discovered significant discrepancies between the actual caloric content and the information provided to the public for 29 restaurant meals and 10 packages of frozen food. On average, the calorie content of the restaurant meals was under-reported by 18 percent, with two side dishes exceeding reported calories by nearly 200 percent. The calorie content information from the packaged food companies averaged 8 percent less than the researchers’ analysis. “If people use published calorie contents for weight control, discrepancies of this magnitude could result in weight gain of many pounds a year,” said senior author Dr. Susan B. Roberts, a professor at the Friedman School of Nutrition Science and Policy at Tufts University.

The study authors attribute the discrepancy between their analysis and the calorie content information from the packaged foods to FDA oversight of Nutrition Fact information labels. Current FDA rules tend to be more lenient towards underreporting calories than over reporting them. However, considering our country’s growing obesity issue, revisions in both policy and standard serving sizes may be in order—something the agency says they are looking into. “We are actively looking at serving size and evaluating what steps we need to take,” said Barbara O. Schneeman, director of the FDA office that oversees nutrition labels. “Ultimately, the purpose of nutrition labeling is to help consumers make healthier choices, make improvements in their diet, and we want to make sure we achieve that goal.”

In addition to revising nutrition information labels to reflect the size of meals Americans actually consume, the FDA may also encourage manufacturers to post the labels on the front of packages instead of the back or side. Officials say the changes could result in a greater sense of public caution about unhealthy foods. “If you put on a meaningful portion size, it would scare a lot of people,” said Barry Popkin, a nutrition professor at the University of North Carolina. “They would see, ‘I’m going to get 300 calories from that, or 500 calories.’”

This isn’t the first time the FDA has vowed to re-examine serving sizes. In 2005 the agency said it was considering changes—an effort that was never accomplished. But with the Obama administration’s renewed focus on tackling obesity, it’s unlikely this key issue will be swept under the rug and forgotten this time around.