According to the Food and Drug Administration, which sets food-labeling guidelines, calorie counts must be accurate within a five-calorie window. Foods containing fewer than five calories per serving can be called "calorie-free." Similar wiggle room is offered for a host of other food components, like trans fats, saturated fat, and total fat. The responsibility for ensuring the accuracy of food labels rests with the food manufacturer, not with the government. However, the FDA does conduct random sampling and testing to ensure accuracy. If a company is found to be in violation, the FDA will take regulatory action. For more information on food-labeling guidelines, go to cfsan.fda.gov.