Calorie labeling can significantly reduce weight gain in college students, according to a recent study.

England researchers found that consistent exposure to prominent calories labeling of main meals reduced the likelihood of young adults gaining any weight over a one-year period by 50 percent.

"Calorie labeling helps people understand what's in their food, and makes them aware of healthier options," Charoula Konstantia Nikolaou, lead researcher of the study, said in a statement. "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."

For the study, Nikolaou and her colleagues examined 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.

Researchers found that during the first year, students gained an average of 7.7 pounds. 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 percent fewer calories than in year one. 

Mike Lean, who supervised the research, said the 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 percent during the year with calorie labeling," Lean said in a statement.

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

The findings were presented during the Obesity Journal Symposium at The Obesity Society Annual Meeting at ObesityWeek 2014 in Boston, Mass.