Protein can also provide energy, especially when the energy provided by fats and carbohydrates does not meet physiological needs, protein can be converted into energy for the body through gluconeogenesis. 1g of protein can provide 4000 calories of energy, the same as 1g of glucose, 1g of fat can provide 9000 calories of energy, 1g of glucose provides 4000 calories of energy, and 1g of protein provides 4000 calories of energy. Protein, fat and carbohydrates are known as the three major energy nutrients, also called macronutrients. Protein is the basis of life, and it is not enough to consume enough energy in daily life; adequate protein is also very important.