Different foods produce different energy. For patients with obesity, diabetes, hypertension and other chronic diseases, controlling the energy intake of the body every day is a way to alleviate their own diseases. Therefore, it is necessary to measure the energy contained in each food for patients to calculate or arrange the total energy contained in each meal.

The daily calories required by a normal person are related to his weight. The relationship between daily calorie intake and body weight ratio is about 1 kcal/hour, that is, 4. 186 kj/hour. So the daily calories of an adult weighing 50 kilograms are as follows:

Heat required = 4. 186 kj * 24 hours * 50kg = 5023.2kj.