Scientists measure food energy by determining the amount of calories contained in different foods. This process typically involves using a device called a bomb calorimeter. The bomb calorimeter measures the heat released when a sample of food is burned in a controlled environment. This combustion process produces energy, and the temperature change in the calorimeter allows scientists to calculate the energy content of the food.
To ensure accuracy, food samples are dried and ground into a fine powder before being placed in the calorimeter. Once burned, the heat generated raises the temperature of a surrounding water bath, and the change in temperature can be used to determine the number of calories released from the food. This method provides a direct measurement of the energy contained in the food, which is essential for understanding its nutritional value and energy yield for human consumption.