Final answer:
A kilocalorie does measure the amount of heat energy, being equal to 1,000 calories. It's the unit used to represent energy from food and is equivalent to the 'calories' typically noted on food labels, which is why confusion can sometimes occur.
Step-by-step explanation:
True, a kilocalorie measures the amount of heat energy. It is a unit of energy equivalent to 1,000 calories. A calorie (with a lowercase 'c') is the energy required to raise the temperature of one gram of water by one degree Celsius. In nutrition, a Calorie (with an uppercase 'C') is the same as a kilocalorie and is the energy needed to raise the temperature of one kilogram of water by one degree Celsius.
The term 'calorie' as used in diet and exercise actually refers to kilocalories, so when you read 'calories' on food packaging, the correct unit they are referring to is kilocalories. The SI unit of energy is the joule, and one calorie has been defined as equal to 4.184 joules. Hence, heat energy from one kilocalorie is sufficient to raise the temperature of one kilogram of water by one degree Celsius. This unit is especially relevant in discussions of energy from food and nutrition.