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Consumers’ estimation of calorie content at fast food restaurants: cross sectional observational study

BMJ 2013; 346 doi: (Published 23 May 2013) Cite this as: BMJ 2013;346:f2907
  1. Jason P Block, assistant professor1,
  2. Suzanne K Condon, director2,
  3. Ken Kleinman, associate professor1,
  4. Jewel Mullen, commissioner3,
  5. Stephanie Linakis, project manager1,
  6. Sheryl Rifas-Shiman, senior analyst1,
  7. Matthew W Gillman, professor14
  1. 1Obesity Prevention Program, Department of Population Medicine, Harvard Medical School/Harvard Pilgrim Health Care Institute, 133 Brookline Avenue, Boston, MA 02215, US
  2. 2Bureau of Environmental Health, Massachusetts Department of Public Health, 250 Washington Street, Boston, MA 02108, US
  3. 3Connecticut Department of Public Health, 410 Capitol Avenue, Hartford, CT 06134, US
  4. 4Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, US
  1. Correspondence to: J P Block jason_block{at}
  • Accepted 25 April 2013


Objective To investigate estimation of calorie (energy) content of meals from fast food restaurants in adults, adolescents, and school age children.

Design Cross sectional study of repeated visits to fast food restaurant chains.

Setting 89 fast food restaurants in four cities in New England, United States: McDonald’s, Burger King, Subway, Wendy’s, KFC, Dunkin’ Donuts.

Participants 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.

Main outcome measure 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.


  • We thank Angela Bannister, Anthony Bean, Deborah Burton, Alanna Burwell, Hilda Castillo, Jamie Chachere, Alicia Johnson, Elise Lauer, Rose Nabehet, Christine Orcutt, Diedra Oretade, Liberty Pande, Maricelle Ramirez, Elyse Rohrer, and Jordan Warner for their help with data collection.

  • JPB presented some results from this study at the Annual Meeting of the Society of General Internal Medicine in May 2011, the Annual Meeting of The Obesity Society in October 2011, and the Annual Meeting of The Obesity Society in September 2012.

  • Contributors: JPB, SKC, KK, JM, SL, and MWG conceptualized the study design and the data collection strategy. JPB, KK, and SR-S conducted the data analyses, and MWG provided critical feedback on the analyses. JPB drafted the manuscript, and SKC, KK, JM, SL, SR-S, and MWG revised the manuscript. All authors approved the final version of the manuscript. JPB is guarantor.

  • Funding: The study was funded by a P30 center grant from the National Heart, Lung, and Blood Institute (P30 HL101312-01, PI: Gillman), a Robert Wood Johnson Foundation Health and Society Scholars seed grant from the Harvard University site (PI: Block), the Robert Wood Johnson Foundation Healthy Eating Research program (grant 70739, PI: Block), and the Robert H Ebert Fellowship, funded by the Harvard Pilgrim Health Care Foundation through the Eleanor and Miles Shore Fellowship Program at Harvard Medical School (PI: Block). The sponsors of this study had no role in the study design, data collection, or analysis for this study and did not require final approval of the manuscript.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at (available on request from the corresponding author) and declare: JPB, KK, SL, SR-S received salary support from the National Heart, Lung, and Blood Institute (NIH) for the submitted work; JPB, SL, and SR-S received support from the Robert Wood Johnson Health Eating Research program; and JPB and SL received support from the Ebert Fellowship.

  • Ethical approval: The study was approved by the institutional review board of Harvard Pilgrim Health Care (approval 0311). Because data collection was anonymous and queried non-sensitive information, the board approved this study without requiring written informed consent from participants. For the same reasons, the board also granted permission for us to interview those aged 11-20, included in the adolescent sample, without parental consent.

  • Data sharing: No additional data available.

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