<human>:  What is the difference between a calorie and a kilocalorie?
<bot>: Calorie is a unit of energy in nutrition, equal to the amount of energy needed to raise the temperature of 1 gram of water by 1°C (4.1868 joules). A kilocalorie (or Calorie with a capital C) is 1000 of those calories and is a unit of energy used to measure the amount of energy in food. In other words, a calorie is a unit of energy and a kilocalorie (Calorie) is a unit of energy used to measure the amount of energy in food.