About one in four people eating at fast-food restaurants underestimate the calorie content of their meals by at least 500 calories, a survey of over 3,000 customers at six fast-food chains suggests.
Teenagers underestimated the calories in fast-food meals by 34%, parents of school-age children by 23%, and other adults by 20%, lead author Jason Block, MD, of Harvard Medical School, and colleagues reported in BMJ.
The researchers interviewed 1,877 adults, 1,178 teens, and 330 school age children ages 3 to 15 (with their parents' help) eating at 89 fast-food restaurants: McDonald's, Burger King, Wendy's, KFC, Subway, and Dunkin' Donuts. At the time of the surveys in 2010 and 2011, none of the chains routinely printed calorie content on menus.
Participants were asked to estimate the calorie content of their meal, and the figures were compared with calculations made based on their receipts.
Two-thirds of the adult participants were overweight or obese, as were 34% of the adolescents and 57% of the school-age children.
Less than one in four participants reported noticing calorie information in the restaurants that did provide them, and less than 5% reported using that information to help them choose their meal.
Overall, two-thirds of participants underestimated the calorie content of their meals. More specifically:
The greater the calories in a meal, the greater the chance a participant would underestimate its actual caloric content, Block said. This finding was also observed in a smaller 2007 survey of 147 diners at food courts, he noted.Both adults and teens who ate at Subway underestimated calorie counts more than diners at any other chain.
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