sentence outline for understanding of calories (1) A calorie, also known as kilocalorie, is a unit of energy. This unit represents the energy required to heat a kilogram of water on degree Celsius. While people generally Link the term calorie with food, it is a unit of measurement that can be applied to any substance possessing energy. For instance, there are 8200 calories in a litter (about one quart) of gasoline. (2) Calories describe the potential energy in food to maintain bodily functions, grow or repair tissue, and perform mechanical work such as exercise. Food calories may take the form of fat, carbohydrates, or proteins. Once consumed, enzymes act on these nutrients through metabolic processes and break them into their perspective categories of fatty acids, glucose, and amino acids. These molecules travel through the blood stream to specific cells where they are absorbed for immediate use or sent on to the final stage of metabolism where they release their stored energy through the process of oxidation. (3) The number of calories burned during an exercise depends on various factors including body weight and the type of exercise. For example, an individual weighing 59 kilograms (130 pounds) would expend roughly 500calories per hour swimming or playing basketball. However, this same person would burn an estimated 200 walking or playing table tennis. In order to survive and maintain body weight, the average individual requires approximately 2000 to 2500 calories per day. Gaining or losing weight is a simple process. Add and subtract 7,700 calories over the course of time to gain or lose a kilogram. Nutrition has nothing to do with it. It is all about calories.​