If we burn off more energy than we replenish, we'll lose weight.So we have to be able to measure the energy we consume and use,and we do so with a unit called the calorie.One calorie, the kind we measure in food,also called a large calorie,is defined as the amount of energy it would take to raise the temperature of one kilogram of water by one degree Celsius.Everything we consume has a calorie count,a measure of how much energy the item stores in its chemical bonds.