Now, count the calories in your food before you eat.

The New York health department has launched a free mobile app to help cooks calculate how many calories are in the food they prepare and find ways to reduce the calorie counts.

Restaurant chefs or home cooks can enter the ingredients and number of servings of a recipe with "CalCutter" and the app will calculate the number of calories per serving in the finished dish, Xinhua reported.

CalCutter will then suggest alternative ingredients or cooking methods to reduce the number of calories in the dish.

"Many people want to count calories as a way to avoid gaining weight, but they have no way of knowing how many calories are in restaurant food or even food they prepare themselves," Health Commissioner of New York Thomas Farley said Wednesday.

"CalCutter is a free, simple tool to help cooks figure out how many calories their recipes deliver. We encourage both restaurant cooks and home cooks to use this tool and prepare food with calorie counts that fit into a healthy diet," he added.

Studies show that most people - including trained dietitians - have great difficulty in estimating the calorie count of foods, which makes it difficult for people to watch calories in order to avoid weight gain.

Diet is one of the most important factors contributing to obesity. Today, nearly 60 percent of New York City adults and 40 percent of children are either obese or overweight.