A new study in the American Journal of Public Health examined how food purchases changed when consumers were given guides on recommended caloric intake to supplement the mandatory calorie information on menus.  The researchers provided recommended intake before and after New York City mandated calorie information on menus to see how eating habits changed.

Researchers used a randomized sample of 1,121 lunchtime diners at two McDonald’s, one in Manhattan and one in Brooklyn.  The study tested for a simple difference in calories purchased, after adjusting for gender, race, age, and day of the week.  They found that calorie guides had no statistically significant impact.  In fact, there was an indication that the guides actually promoted a marginal increase in calories, though this impact was not statistically significant.

Researchers hypothesized that calorie guides would have reduced or moderated caloric intake.  As a whole, women consumed approximately 27 percent more calories than they should have and men consumed 11 percent more than recommended.  After seeing the indication that these guides may actually increase calories purchased, the study authors theorized that diners may have had a false sense of security.  While their entrée was within the recommended allowance, they might not have taken into account additional calories from a drink or fries.

An earlier study found that most people underestimate the number of calories in their fast food meals.  That study, conducted at several fast food chains, found that one in four participants underestimated the calories in their meals by 500 calories or more.  If participants only consider the entrée, they may be within the guidelines, but are likely underestimating how many calories other items contribute.

The current study contradicts earlier findings, which studied the use of calorie information also before and after New York City enacted labeling laws.  Based on self-reported behavior, more than double the consumers were now aware of calories in their meals.  They also reported that they used this information to help make decisions about their meals.  Another study has shown that providing calorie recommendations helps keep meals within the recommended allowance, but that study was conducted at another chain and seemed to only have an impact on those that were already at a healthy weight level.

On average, adult men should consume 2,500 calories and adult women 2,000 calories.  If eating three meals per day, caloric intake at each meal should be between 650 and 700 for women and between 800 and 850 for a man.  Snacks should be at or below 200 calories and, if consuming snacks, calories at other meals may need to be reduced.