Teens, Adults Underestimating Calorie Content in Fast Food Meals: Study

Many people underestimate the number of calories that they are getting from a fast food meal, especially a large meal, a new study reported. Adults, teens and parents of school-age children were the worse guessers of calories in food.

Currently, a third of all people living in the U.S are obese and about 17 percent (or 12.5 million) of children and adolescents are obese, according to estimates by Centers for Disease Control and Prevention.

Poor lifestyles such as eating high calorie food and lack of physical activity are the most common causes for gaining weight although in some cases the gain in weight may be linked with genes, family history, medications etc.

An earlier study found that a third of all fast food purchases contain more than 1,000 calories, which is ideally half the calories required per day.

The present study by researchers from the Harvard Medical School/Harvard Pilgrim Health Care Institute along with their colleagues in Massachusetts and Connecticut Departments of Public Health has shown that people are grossly underestimating the number of calories that they are getting from a meal.

"We found that people, especially teens, are consuming more calories than they think they're getting when they eat fast food. Teens underestimate the number of calories in their meals by as much as 34 percent, parents of school-age children by as much as 23 percent, and adults by as much as 20 percent," said Jason Block, MD, of the Harvard Medical School/Harvard Pilgrim Health Care Institute and lead author of the study, according to a press release.

The study included 3,400 adults, teens, and school-age children. Researchers interviewed these people in 2010 and 2011 at 89 fast-food restaurants across four New England cities. The restaurants included McDonald's, Burger King, Wendy's, KFC, Subway and Dunkin' Donuts. Also, at the time of the survey, none of the restaurants displayed the amount of  calories per meal in their menus.

The study found that adults ordered meals that typically contained more than 800 calories, but underestimated the content by at least 175 calories. Teens consistently underestimated the number of calories that they were getting from a meal. They had a gap of more than 200 calories while parents of young children underestimated the calorie content by 175 calories.

Interestingly, about a fourth of all participants were way off the mark by underestimating the calorie content by as much as 500 calories per meal.

The study also found that people eating at Subway were most likely to underestimate the calorie content of the meals than people eating at other places such as McDonald's, Burger King, KFC, Wendy's. Subway's marketing might have created the health halo among the public, suggested Block.

Between 2006 and 2010 many States and cities in the U.S. passed orders that required restaurants to print calorie content on the menus. A similar provision was included in the U.S. Patient Protection and Affordable Care Act of 2010 that required all restaurant chains with outlets in 20 cities to have calories marked in their menus. 

The study is published in the journal bmj.