The so-called 'low-calorie' foods in restaurants and supermarkets contain more calories than indicated on the label, has been found by Tufts University researchers.
The researchers measured energy values of 29 quick-serve and sit-down restaurant foods and found that it had, an average 18pct more calories than the stated values.
Similarly, measured energy values of 10 frozen meals purchased from supermarkets averaged 8pct more calories than stated on the label.
"These findings suggest that stated energy contents of reduced-energy meals obtained from restaurants and supermarkets are not consistently accurate, and in this study averaged more than measured values, especially when free side dishes were taken into account, which on average contained more energy than the entrees alone," said lead investigator Susan B. Roberts, PhD, director, Energy Metabolism Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA.
"For example, positive energy balance of only 5pc per day for an individual requiring 2,000 kcal/day could lead to a 10-lb weight gain in a single year.
"If widespread, this phenomenon could hamper efforts to self-monitor energy intake to control weight, and could also reduce the potential benefit of recent policy initiatives to disseminate information on food energy content at the point of purchase," the researchers added.
The study published in the Journal of the American Dietetic Association.