It’s almost painfully obvious now that obesity is a serious problem in the United States. Over a third of U.S. adults are obese, and obesity-related diseases such as cardiovascular disease, diabetes, and stroke are among the leading causes of death. These numbers are unfortunately on the rise — but why? Here, health experts and nutritionists agree: the surge in obesity is due almost entirely to overeating.

Legislators and doctors have tried countless strategies in an attempt to curb this epidemic. One of these strategies is menu labelling: requiring major restaurants to print the number of calories next to each item on their menus. According to the FDA, Americans eat about one-third of their calories outside the home. As the FDA puts it, “making calorie information available will help consumers make informed choices for themselves and their families.” Surely this is a noble intention, especially in a country where single-person entrees can run over 2000 calories. The intuition behind such laws makes sense too —consumers who see the astronomically high number of calories in their favorite burger may think twice about eating it too often. But intuition can only take us so far — what do the data say?

Unfortunately, it doesn’t look good. In 2008 and 2009, researchers measured restaurant ordering in two U.S. counties, one of which later implemented menu-labeling. No significant difference was observed between the two areas in terms of the number of calories ordered. A 2015 systematic review and meta-analysis consolidated the results of 19 studies on the effect on calorie labeling. The result: the presence of menu labels only led to an underwhelming 18-calorie reduction per meal (however, the authors note that many of the studies were performed in artificial conditions, and may not be realistic).

The presence of menu labels only led to an underwhelming 18-calorie reduction per meal.

There’s another problem — just how accurate are the stated calorie counts on those menus? In a 2011 study, researchers went into 42 different restaurants with menu labeling, and purchased a total of 269 food items. They took those foods back to their lab, and measured their caloric content using accurate bomb calorimetry techniques. How accurate were the labels? Overall, the results weren’t too bad — the difference between the stated calorie content and actual calorie content was not statistically significant. However, there was a lot of individual variation. 19% of the food items contained over 100 more calories than stated (the most egregious case was a side dish that had over 1000 more calories than stated). Worryingly, it was the “healthy” foods that were most likely to have understated calorie counts. Now, this isn’t to say that restaurants are deliberately lying — calorie contents aren’t easy to determine, after all — but relying on menu labels may be misleading for those trying to control what they eat.

There are a few other problems, too. The idea behind menu labeling is to give customers more information that they can use to choose healthier lifestyles. But it’s not clear that this extra information actually leads to smarter dietary choices. Plus, imposing such requirements has real costs to businesses (the economics term “menu cost” could not be more appropriate here).

Let us not be hasty — this is not to say that we should eliminate menu labeling. Communicating better information to consumers has value in and of itself. But we must be realistic in what to expect from health regulations. Curbing obesity is a real and pertinent issue, but if the example of menu-labeling has taught us anything, it is that the worth of any policy can only be judged by real-world data.

About The Author

Daniel Liu
Editor-in-Chief emeritus

Hailing from the quiet suburbs of Potomac, Maryland, Daniel is the former editor-in-chief of Innovation. He studies molecular biology at Princeton, with a particular research interest in cancer stem cell biology and the molecular pathways governing metastasis. Outside of academics, Daniel also enjoys painting and drawing in his free time.