Why restaurants hate putting calories on menus

From Bible studies meeting at the local cafe bakery to lunch out after church, people are more conscience of the calorie count in prepared food and they’re looking at the menu. A new study by Cornell researchers has found that customers order less at full-service restaurants that list calories for their food.

“Even if you’re an educated person who eats out a lot and is aware of nutrition, there can still be surprising things in these calorie counts,” explains co-author John Cawley, professor of policy analysis and management in Cornell’s College of Human Ecology in a statement.

Even chefs at restaurants involved in the study were surprised by some of the high calorie counts on some of their menu items, specifically a tomato soup/grilled cheese sandwich combo, which many chefs incorrectly guessed was low in calories. That could set you back 2,400 calories–your entire daily intake.

Customers whose menus listed the calories of their meals ordered options with 3% fewer calories (roughly 45 calories less) than customers who had menus without any calorie information. When broken down by meal type, the researchers found that customers ordered fewer calories in their appetizers and entree courses when the calorie numbers were listed, but their dessert and drink orders stayed the same.

That 3% drop in calories equates to an average reduction in weight of about one pound every three years, the researchers estimated. Of course, that estimation changes depending on how often a specific individual dines out.

Previous research has shown that about one-third of the average American diet is food prepared outside the home, making it difficult for most people to get an idea of how many calories they are consuming on a daily basis. Meanwhile, obesity rates have continued to increase, causing many US. states, counties, and cities to require that all restaurants display calorie counts for their food.

The researchers conducted a randomized field experiment centered on two restaurants that didn’t typically display calorie information on their menus. Across both restaurants, there was a wide variety of either high-calorie or low-calorie dining options. In one restaurant, appetizer calories ranged from 200 to 910. Entrees were between 580 and 1,840 calories, and desserts between 420 and 1,150 calories.

Participants were assigned to either a control group, which received normal menus without calorie counts, or a treatment group, which received the same menus but with calorie counts beside each menu item. In all, 5,550 diners took part in the study.

Overall, researchers found that diners who had access to the calorie counts ended up ordering food with less calories. Additionally, most diners across both groups said they preferred being given calorie information.

“It’s clear that people value this information,” Cawley adds.

The study was published by the National Bureau of Economic Research.