Calorie labels can lie

Many cities, including New York, require chain restaurants like Au Bon Pain and McDonald’s to list the calorie content of the food they sell. It’s an effective way to get people to eat less: for example, a recent Stanford study found that Starbucks customers curbed their food consumption an average of 6% each (and people who generally ate 250 calories or more cut their calories a whopping 26%) after the coffee peddler started posting calories.

Trouble is, those calorie estimates aren’t always accurate, according to a new Tufts University study. Researchers measured the energy values of 29 fast food and sit-down restaurant meals and found that on average, they contained 18% more calories than they stated. That’s a lot: a meal labeled 400 calories would contain an extra 72.

What’s more, the same study examined 10 frozen meals from the supermarket and found that their calorie values were too low by an average of 8%.

Cause to freak out? Nope. But there’s little doubt that this is one more reason not to polish off every last morsel of your meal.

–Camille