title: Consumers' estimation of calorie content at fast food restaurants: cross sectional observational study.
abstract: OBJECTIVE
  To investigate estimation of calorie (energy) content of meals from fast food restaurants in adults, adolescents, and school age children.
  
  
  METHODS
  Cross sectional study of repeated visits to fast food restaurant chains.
  
  
  METHODS
  89 fast food restaurants in four cities in New England, United States: McDonald's, Burger King, Subway, Wendy's, KFC, Dunkin' Donuts.
  
  
  METHODS
  1877 adults and 330 school age children visiting restaurants at dinnertime (evening meal) in 2010 and 2011; 1178 adolescents visiting restaurants after school or at lunchtime in 2010 and 2011.
  
  
  METHODS
  Estimated calorie content of purchased meals.
  
  
  RESULTS
  Among adults, adolescents, and school age children, the mean actual calorie content of meals was 836 calories (SD 465), 756 calories (SD 455), and 733 calories (SD 359), respectively. A calorie is equivalent to 4.18 kJ. Compared with the actual figures, participants underestimated calorie content by means of 175 calories (95% confidence interval 145 to 205), 259 calories (227 to 291), and 175 calories (108 to 242), respectively. In multivariable linear regression models, underestimation of calorie content increased substantially as the actual meal calorie content increased. Adults and adolescents eating at Subway estimated 20% and 25% lower calorie content than McDonald's diners (relative change 0.80, 95% confidence interval 0.66 to 0.96; 0.75, 0.57 to 0.99).
  
  
  CONCLUSIONS
  People eating at fast food restaurants underestimate the calorie content of meals, especially large meals. Education of consumers through calorie menu labeling and other outreach efforts might reduce the large degree of underestimation.
authors.affiliation: Obesity Prevention Program, Department of Population Medicine, Harvard Medical School/Harvard Pilgrim Health Care Institute, 133 Brookline Avenue, Boston, MA 02215, USA. jason_block@harvardpilgrim.org
authors.forename: Jason P
authors.initials: JP
authors.lastname: Block
authors.forename: Suzanne K
authors.initials: SK
authors.lastname: Condon
authors.forename: Ken
authors.initials: K
authors.lastname: Kleinman
authors.forename: Jewel
authors.initials: J
authors.lastname: Mullen
authors.forename: Stephanie
authors.initials: S
authors.lastname: Linakis
authors.forename: Sheryl
authors.initials: S
authors.lastname: Rifas-Shiman
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Gillman
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002755:Choice Behavior; D016000:Cluster Analysis; D003254:Consumer Advocacy; D003430:Cross-Sectional Studies; D002149:Energy Intake; D057140:Fast Foods / Q000592:standards / Q000706:statistics & numerical data; D005260:Female; D005515:Food Labeling / Q000592:standards / Q000706:statistics & numerical data; D007722:Health Knowledge, Attitudes, Practice; D006293:Health Promotion; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009511:New England / Q000453:epidemiology; D009765:Obesity / Q000453:epidemiology / Q000517:prevention & control*; D012147:Restaurants / Q000592:standards / Q000706:statistics & numerical data; D017678:Sex Distribution; D011795:Surveys and Questionnaires