Final answer:
An issue with the caloric values on food labels is that the term 'Calories' actually refers to 'kilocalories', potentially causing confusion about energy content. The caloric content is estimated using the Atwater system, based on the average caloric values from bomb calorimetry.
Step-by-step explanation:
An "issue" with the caloric values contained on food labels is that the calorie unit used for foods is actually the kilocalorie (kcal). For example, when a food label shows a calorie content of 500 Calories, it really means 500 kilocalories, which is 500,000 calories. This difference in terminology can potentially lead to confusion about the amount of energy a food contains. Furthermore, the method used to determine the caloric content on food labels is known as the Atwater system. It estimates energy content by multiplying the amounts of carbohydrate (discounting fiber), protein, and fat by average Calories per gram for each, which are values obtained from bomb calorimetry.