A 'calorie detective' found something shocking about the calorie listings on food labels

Walk into any grocery store or bodega for a packaged snack and you'll probably be able to find the nutritional information. Or if you're stopping by a fast food spot or chain restaurant, chances are you'll be reminded of just how many calories you're about to consume, thanks to the listings on the menu.

How spot-on are these listings?

Filmmaker Casey Neistat decided to test the accuracy for himself on five different food items, with the help of two food scientists and their bomb calorimeter at the New York Obesity Nutrition Research Center at St. Luke's-Roosevelt Hospital Center.

"By testing only five items, my little study is hardly conclusive," he writes on The New York Times. But his findings certainly raise a few red flags.

Here's what he found and documented in his 2013 short film, "The Truth Behind Calorie Labels:"