The body greatly needs a supply of protein to carry out important processes that maintain health and survival. Protein plays a role in almost every cellular function of the body, including immune regulation, hormone production, growth, and much more. Research also shows that consuming more protein than the recommended amount in the Recommended Dietary Allowance (RDA) can help in the formation and maintenance of muscle mass during weight loss processes.

Protein provides the body with amino acids, which are referred to as the "building blocks" of protein. When we consume food containing protein, the body breaks it down into the necessary amino acids for the synthesis of new proteins and other important compounds, such as neurotransmitters. Some specific amino acids are crucial for increasing muscle mass, such as valine, leucine, and isoleucine, which together are known as branched-chain amino acids. Individuals who are trying to build muscle require a higher intake of protein compared to those who are simply maintaining their muscle mass.

The Nutrient Adequacy Level (AKG) for protein has currently been set at 0.8 grams per kilogram (g/kg) of body weight. Adhering to the AKG recommendation can help maintain muscle mass for individuals who are not very physically active. However, for individuals who are active and want to increase their muscle mass, this amount is not sufficient. Research shows that physically active individuals, such as those who regularly exercise, should consume between 1.2 to 2.0 g/kg of protein per day to maintain healthy muscle mass. Meanwhile, for those actively trying to build muscle mass, a higher intake of protein is required than the aforementioned range.

For individuals who want to maintain weight while increasing muscle mass, experts recommend a daily protein intake between 1.6 and 2.2 grams per kilogram of body weight. However, for those actively trying to lose weight while maintaining or increasing muscle mass, the daily protein requirement is higher, ranging from 2.3 to 3.1 grams per kilogram of body weight. This is due to the decrease in energy intake that increases the risk of muscle loss.