Do you check the calorie count when you dine out or shop at your local natural and organic food store?

A study to be published in the August issue of the American Journal of Public Health reveals that consumer knowledge does affect buying decisions.

This particular study focused on fast-food consumers. Researchers examined their behavior when calorie information was displayed at 11 different fast-food chains.

Approximately 7,300 customers were surveyed at 275 randomly selected fast-food restaurants in New York City. While patrons purchased an average of 827 calories, only 4% reported seeing calorie information provided onsite (with the exception of Subway, which places calorie information on deli cases near the register).

One-third of Subway patrons reported that the posted information influenced their purchases. Those who reported seeing it purchased an average of 52 fewer calories than those who did not.

“Fast food, which represents approximately 74%  of all restaurant traffic nationally, typically contains more calories per serving than does food prepared at home,” the authors write. “Placement of calorie information at point of purchase is more effective and may be associated with lower calorie purchases among consumers who report seeing information.”

Our advice: Brown-bag it organically—and start requesting calorie information from the restaurants you frequent.