First long-term study on calorie labeling shows strategy effective in reducing weight gain by 50%

"Calorie labeling helps people understand what's in their food, and makes them aware of healthier options," says lead researcher Charoula Konstantia Nikolaou, BSc, MSc, RD, member of The Obesity Society (TOS) and PhD student at the University of Glasgow, Scotland. "Previous literature has shown little or no benefit from calorie labeling, however that research did not look at long-term exposure, and in those studies most consumers did not notice the calorie labels. We were glad to see that exposure to our very prominent calorie labeling for an entire school year did not just reduce weight gain in these students, but eliminated it altogether for the group. This is especially important because young adults are vulnerable to weight gain, which often leads to obesity later in life."

Nikolaou conducted her study by examining food choices and weights of university students from two 36-week academic years. In one year, the college dining room displayed caloric information for main meals for a pilot period 5 out of 36 weeks, and in a second year, caloric information was displayed on large colorful cards for all main meals for 30 out of the 36 weeks.

As expected, during the first year, students gained an average of 7.7 pounds (3.5 kg). In the second year, students maintained their average initial weight, unchanged. Most students surveyed in year two reported using the calorie labeling for weight control and healthier eating, and overall they ordered meals with 18% fewer calories than in year one. These meals had less fat, saturated fat and frying oils than meals ordered in year one, and there was no decline in micronutrient consumptions in year two.

Nikolaou's PhD research was supervised by Dr. Catherine Dankey and Professor Mike Lean, who explain that this tactic represents a very low-cost, transferable intervention that proved effective.

"The caterers were impressed with the effectiveness of tactic as well, because their spending on food ingredients was lowered by 33% during the year with calorie labeling," said Professor Mike Lean.

This lower cost of ingredients offsets what caterers and food companies often argue, that healthier ingredients are more costly.

"Although the policy is encouraged in the U.S. and U.K. for large chain restaurants to present caloric content for menu items, this study reminds us that there isn't any legislature for cafeterias at universities, schools or workplaces to display this type of information," says Sara Bleich, PhD, Associate Professor at Johns Hopkins Bloomberg School of Public Health, speaking on behalf of TOS. "The sooner policymakers better understand these associations between calorie labeling and weight loss, the closer we will all be to making better food choices."