Wednesday July 27 2011
The study looked at fast food regulations in New York
“Calorie counts on menus prompt healthy choices,” BBC News has today reported, saying that US research has found it helps healthy eating “but only in a limited way”.
The research involved a survey of thousands of customers at 11 top fast food chains in New York City (NYC) before and after full implementation of regulations requiring chain restaurants’ menus to contain details of the calories in all menu items. The study aimed to assess the impact that labelling had upon customer choices, but found no overall difference in the total calories per purchase, although there were reductions at three fast food chains that accounted for 42% of all customers surveyed. Overall, 15% of customers reported that calorie labelling had informed their meal choice, and these people consumed fewer calories on average.
While this study has value in being reportedly among the first to assess the effectiveness of a calorie-labelling regulation, there are some limitations. These findings are specific to fast food chains in New York, and a third of those surveyed came from impoverished neighbourhoods, therefore it cannot be assumed that displaying calorie information elsewhere and among other socioeconomic, cultural and ethnic groups will have the same effect. Also, the study cannot tell us what longer-term implications the regulations will have on health or obesity.
Research specifically looking at the effect of similar measures in the UK would be valuable.
Where did the story come from?
The study was carried out by researchers from institutions in New York and California and was funded by the City of New York and by the Robert Wood Johnson Foundation Healthy Eating Research Program. The study was published in the peer-reviewed British Medical Journal.
BBC News and The Guardian have accurately reflected the findings of this report in their main text, but their headlines take varying slants on the results. The BBC was more optimistic in suggesting that calorie information can aid healthy food choices, but The Guardian highlighted that it only influenced a relatively small proportion of customers.
What kind of research was this?
This research used cross-sectional customer surveys to asses the impact of regulations requiring chain restaurants in NYC to display details of the calorie content of all menu items. These surveys were given at several top fast food chains in spring 2007 and spring 2009, or before and after the implementation of the legislation. The study’s aim was to assess the impact that calorie labelling had upon customer choices.
This type of assessment is often the way that large public health programmes are assessed after they have been implemented. When interpreting the findings it is important to remember that factors other than the programme may be influencing any changes seen.
What did the research involve?
In 2006 a regulation was passed in NYC that required chain restaurants to display the calorific value for all items on menus and menu boards, as part of the US's strategy to combat obesity. Following this step, the city approved a second health code regulation in March 2008 requiring chain restaurants with 15 or more stores nationwide to list calorie information prominently on all menus, menu boards and item labels. When the policy was introduced, labelling the calories in fast food items was considered to be an innovative step and there was only limited data on the effectiveness the measure might have.
The study included a random sample of 275 food outlets from the total 1,625 that were said to be covered by the 2006 regulations. The sample featured outlets belonging to 13 chains. These locations were assessed over nine weeks in spring 2007, and then followed up in spring 2009 (but by this time 22 outlets had closed or did not allow further data collection).
The researchers say that in 2007 only one chain (Subway) provided calorie information, but only for a small number of items. However, by 2009 all chains included in the study were considered to be “largely in compliance with the new regulations”, although there were variations in the way the regulations were implemented, such as in the size and prominence of the information.
After excluding two coffee chains and their 109 outlets, the researchers were left with a sample from 168 outlets belonging to 11 fast food chains. They had set a goal to survey 55 customers at each outlet, aiming for an overall sample of at least 3,600 people in each sample year. From 12pm to 2pm on weekdays, adult customers were approached as they entered the restaurant and asked to provide their register receipts when exiting and to complete a brief survey. This asked questions such as whether they saw calorie information and if the information affected their purchase.
The main outcomes the researchers examined were changes in average energy content (kcal) per purchase after regulation, and the average energy content of purchases made by customers who said that they used the calorie information when deciding what to order.
What were the basic results?
The final study sample across the 11 chains included 7,309 customers from the 2007 survey and 8,489 from the one in 2009. Overall, more than 80% of all customers were approached, of whom 60% responded. A third of receipts came from locations in very poor neighbourhoods, and McDonald’s and Subway together accounted for 58% of all receipts collected.
Overall, purchasing patterns were found to be similar in the two time periods, and average calories per purchase did not change (828 vs. 846 kcal), although slightly fewer customers purchased a drink in 2009 (54%, compared with 58% in 2007). There were reductions in average calories per purchase at three major chains, which accounted for 42% of customers surveyed (McDonald’s 829 kcal in 2007 vs. 785 in 2009, Au Bon Pain 555 vs. 475 and KFC 927 vs. 868). The average energy content increased at one chain (Subway 749 vs. 882 kcal).
In 2009, 15% of customers overall reported using the calorie information when deciding on their purchase for that day (18% of women and 13% of men). These 15% of customers purchased foods with fewer calories on average (757 vs. 863). Customers in wealthier neighbourhoods were also more likely to use this information (19%) than customers in moderate-poverty (17%) or the poorest neighbourhoods (12%).
How did the researchers interpret the results?
The researchers concluded that, although there was no overall decline in calories purchased across the full sample, several major chains saw significant reductions between 2007 and 2009. After regulation, they say that one-in-six lunchtime customers used the calorie information provided, and these customers went on to make lower calorie choices.
Fast food intake has often been linked to higher overall calorie intake, but information on the fat, sugar and calorie content of the food in restaurants and takeaways is often unavailable. There is currently a great deal of discussion over how similar labelling schemes might be adopted and what benefits they might have to the public. This particular study surveyed a large number of customers in 11 fast food chains in New York, both before and after the adoption of new regulations requiring them to display calorie content on their menus.
The implications of this study’s results are themselves open to debate, as illustrated by the slightly different slants offered by BBC News and The Guardian. The BBC has positively highlighted the fact that around 15 % of customers reduced their calorie intake in response to the information, while The Guardian has focussed on the fact that it made no impact on most consumers.
In order to assess the implications of the study’s results it is important to look at the research in context:
- These findings are specific to fast food chains in NYC, and a third of those surveyed came from very poor neighbourhoods. It cannot be assumed that the effect of displaying calorie information elsewhere and among other socioeconomic, cultural and ethnic groups will be the same as in this particular case.
- Surveys found no overall difference in the calorific content of purchases across the 11 chains, although three individual fast food chains did demonstrate reductions in calories per purchase after the regulations. While this study cannot confirm either way, it may be the case that the regulations have led food vendors to reduce the calories in their food items, so the regulations might have some impact beyond simply changing consumers' eating habits.
- From this study it is not yet clear whether the regulations will have any longer-term effects on people’s health or weight.
- While this study can tell us about the calories in individual portions, it cannot provide important information such as how frequently these people were purchasing fast food, whether it made people avoid fast food altogether, or whether labelling affected their other dietary choices. It might be the case that people still buy the same products but reduce the frequency of their visits in response to calorie information, or choose less calorific options for their meals later in the day.
- The surveys were conducted at lunchtime on weekdays in NYC: it may be the case that lunch choice was dictated by necessities such as needing to eat something quickly. The study does not tell us about how people might choose food at less busy times such as weekends or evenings, when they have more time to consider their choices.
Overall the study provides only a partial representation of how calorie labels on fast food might influence eating habits, and probably only represents the specific setting and legislation of New York. That said, it is nevertheless of value as a means of examining how similar programmes could be implemented, and is said to be among the first to assess the population-level effects of a calorie-labelling regulation.
The authors of the report say that in UK, 28 organisations have pledged to implement similar labelling in 2011 as part of the Department of Health’s voluntary Responsibility Deal programme, and these include some food chains that have been required to provide calorie labels in NYC. Similar before-and-after studies in the UK would be valuable for understanding the impact of the scheme.