What You Don't Know Will Make You Fatter: Displaying Calories Helps Keep the Pounds Off

Revealing the calorie content of meals on ordering displays and in menus can drastically reduce the weight gain in those that regularly visit those establishments, a study from the University of Glasgow shows. This is the first in-depth study of how labeling meals has a health benefit to consumers. The study was published in the November issue of the journal Obesity.

The Scottish researchers used a college residence hall cafeteria for its study, and the study took place across two school years. Students who saw the calorie counts of foods in the cafeteria had reduced weight gain by an average of nearly 8 pounds.

Students eat at residence-hall dining facilities regularly as two meals, breakfast and dinner, are typically provided as part of accommodation fees, providing researchers with a way to test whether showing calorie counts help people make healthier food choices.

In the first year of the study, calorie counts were displayed for main meals for of five out of 36 weeks. In the following year, calorie information was displayed on large colorful for 30 out of the 36 week school year. At the end of the first year, the subjects, who only saw calorie counts for five weeks, gained 7.7 pounds on average. But in the second year of the study, the weight of the students, who saw the calorie counts for all but four weeks, remained unchanged on average.

As a control, the researchers also looked at the weight changes of those attending the university, but not living or eating at residence facilities. During the first year of the study, they found that these students gained 4 pounds, while similar students gained about 4.5 pounds during the second year of the study.

Researchers say that their study proves that displaying calorie information has a net positive effect on people’s weight.

"Calorie labeling helps people understand what's in their food,” said Charoula Konstantia Nikolaou, the study’s author.

The researchers say that while previous studies had shown little health benefits, this is the first study that took a long-range approach, about 9 months.

"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,” says Nikolaou. “This is especially important because young adults are vulnerable to weight gain, which often leads to obesity later in life."

After the study was conducted, an economic benefit for the cafeteria was noticed as well. Professor Mike Lean, one of the study’s supervisors said, "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.”

"Calorie Count Laws" have been a controversial issue in municipal and state houses across the nation. Many in the U.S. require restaurants (or in some cases only restaurant chains) to publish calorie and nutritional information on the food they serve. The first law was enacted in 2009 in New York City. Since then, several municipalities in California have enacted such laws. Several other states and municipalities across the country are considering similar legislation.