Every gram of carbohydrate can produce 4 kilocalories. Carbohydrate is one of the three most productive substances in human body. Protein and fat can also generate heat. 1g protein can generate about 4 kilocalories, and 1g fat can generate about 9 kilocalories. Carbohydrate, in particular, are that main energy sources for physical activity.

The role of heat is just like that of computers, trucks and human daily activities. Heat not only provides energy for people's exercise, daily work and life, but also provides energy for human life activities, blood circulation, breathing, digestion and absorption. People who lose weight can burn fat through exercise, which can accelerate calorie consumption and achieve the goal of healthy weight loss.

The heat source comes from carbohydrate, fat and protein.

Carbohydrate generates heat energy =4 kcal/g.

Heat generated in protein =4 kcal/g.

Heat produced by fat =9 kcal/g.