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.
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.
In this study of diners at fast food chain restaurants in four New England cities, we found that participants purchased large meals, and adults, adolescents, and (parents of) school age children underestimated the calorie content of those meals by 175 calories, 259 calories, and 175 calories, respectively. Nearly a quarter of adults, adolescents, and (parents of) school age children underestimated meal calorie content by 500 or more calories. Estimated calorie content was strongly associated with actual calorie content for each of the samples. Noticing calorie information in the restaurant had no effect on the accuracy of calorie estimations.
In a study of 147 fast food restaurant diners at food courts, Chandon and Wansink also found that people underestimated the calorie content of purchased meals, with larger underestimation for higher calorie meals and no association with recognition of nutritional information in the restaurants.2 Compared with that study and other previous research,1 4 our study has the advantages of a large sample size, comparison of diners at six restaurant chains across four cities, recruitment of a racially and ethnically diverse study population in three age groups, and investigation of predictors of underestimation.
Adult and adolescent diners at Subway restaurants estimated lower calorie content than diners at the other chains. These findings suggest a consistent “health halo” for Subway in these age groups. In a study of 518 participants eating meals with equivalent calorie content at McDonald’s and Subway, Chandon and Wansink found that participants estimated 151 fewer calories at Subway than at McDonald’s.3 Participants also ordered side dishes with more calories at Subway. Dieticians also falsely considered equivalent calorie meals to be lower calorie at Subway than McDonald’s.3Our study extends these findings by showing that this “health halo” is unique to Subway across the six chains and is present across age groups in a diverse sample.
Branding could be an important component of Subway’s “health halo.” Marketing researchers have found that brand positioning is particularly important in guiding consumer choices when specific information about products is not available.8 For example, simply labeling a food item as “heart healthy” led consumers in one experiment to conclude that the item conferred a lower risk of heart disease and stroke than similar unlabeled foods.9 Subway’s positioning as a “healthier” fast food option might lead consumers to view its food as lower calorie, especially when calorie information is not readily apparent.
The forthcoming US federal regulation on labeling calorie content on menus could alter this “health halo” by providing easily accessible information on menus and menu boards.10 11 Previous research has found that information can be most powerful when it contradicts previous expectations (in this case, improper estimation of calorie content of foods with a “health halo”).12 Unlike previous state and local regulations, the federal regulation will also require an anchoring statement that indicates recommended total daily calorie requirements. In our study, participants’ estimates of meal calories strongly correlated with their estimates of total daily requirements, supporting inclusion of daily requirements on menus as an “anchor.” Thus far, research about the effects of calorie menu labeling, in both real world and experimental settings, has been mixed.113 14 15 16 17 18 19 20 21 22 23 24 25 26 It is difficult to ascertain why these studies had inconsistent results, but differing study designs, demographic characteristics, the rare use of an anchoring statement, and weight status might be involved.
In addition to providing an anchoring statement on menus, policymakers could perhaps improve menu labeling by supporting social marketing campaigns to better explain the concept of calories. These efforts could bolster not only menu labeling but nutritional labeling of packaged foods.
In this study of over 3000 diners at six fast food restaurant chains across four diverse New England cities, we found that adults, adolescents, and parents of school age children generally underestimated the calories of meals, especially if the meal was large. Adults and adolescents dining at Subway underestimated calorie content more than diners at other chains. The forthcoming calorie menu labeling requirements of the US Patient Protection and Affordable Care Act might help to correct underestimation of calorie content.
What is already known on this topic
- Consumers are known to underestimate the calorie content of restaurant meals, especially for large calorie meals
- Previous studies have been conducted in experimental settings without monitoring consumer choices at actual fast food restaurants, have focused on a narrow range of fast food restaurants, or have enrolled samples with limited racial/ethnic or age group diversity
- All age groups and racial/ethnic groups studied underestimated the calorie content of meals from fast food restaurants
What this study adds