Washington, Sep 24: Providing calorie information, either through numbers or icons such as traffic lights, encourages diners to take in fewer calories, a new study has found.
The US Food and Drug Administration requires most chain restaurants to state the number of calories that each menu item contains to help diners make low-calorie choices.
"In our particular study, either method resulted in food choices that contained 10 per cent fewer calories," they said.
To determine the effectiveness of numbers and traffic lights, the researchers from Carnegie Mellon University in US conducted a field experiment in which employees at Humana, a health-care company, were asked to place lunch orders through an online platform designed especially for the study.
A control group was given no calorie information. In the experimental group, employees were given either the number of calories, a traffic light indicating the approximate number of calories (a green light, for instance, meant the fewest calories), or both.
The study provides the most promising evidence to date that providing calorie information, either through numbers or icons such as traffic lights, encourages diners to take in fewer calories.
Although providing calorie information in the form of numbers may seem like the best option, policymakers should consider that not all consumers are adept at interpreting numbers.
"For those consumers, traffic light labels can communicate basic 'eat this, not that' information regardless of their understanding of the underlying nutrients or ability to use numeric information," the researchers said in a study published in the Journal of Public Policy and Marketing.
A study earlier this year from the University of Birmingham had found that traffic light labels on food packaging confuse consumers and may hinder attempts to promote healthy diets and reduce obesity.