How is the calorie count in food measured? Well, let us start at the definition of a calorie. A calorie is the unit of heat equal to the amount of heat required to raise the temperature of 1 kilogram of water by 1°C. It is also a measurement of the amount of heat or energy produced by food, according to Webster's Dictionary. Calories come from many different sources, which are carbohydrates, lipids (fats), proteins, and some calories are from alcohol. A carbohydrate is a group of compounds, including starches, celluloses, and sugars that contain carbon, hydrogen and oxygen. A lipid is any oily organic compound insoluble in water but soluble in organic solvents; essential structural component of living cells. A protein is any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of long strings of amino acids. As you can see...