If you want to gain weight and build muscle mass, you should pay attention to the carbohydrate intake while consuming enough protein. You can think about it this way, which I call it the “ideal muscle building law”. Keep in mind it is the ideal case but perfectly explain some of the relationship between nutrient intakes and body functions.
All the protein you eat should be turned into muscle mass and all the body’s energy source should come from carbohydrates.
With that being said, you should not be on a low-carbohydrate diet. A low-carbohydrate diet acts as a way to lose weight in 3 reasons:
1. Reduced carbohydrate consumption forces the body into ketosis, in which products of fat are broken down and turned into ketone bodies for energy. However, ketone bodies cannot be further metabolized by the body and are then excreted in the urine. Thus, fats are gone and you lose calories and weight.
2. On a low-carbohydrate diet, muscle glycogen is broken down to glucose. Glycogen holds on to water, but when it is broken down on the low-carbohydrate diet, the water is released. Thus water is lost as urine, which accounts for weight loss.
3. If the carbohydrates are restricted, the body begins to use protein as a source of calories. It’s not ideal because body needs protein for maintenance of muscle and organ function and also the immune system. If sufficient carbohydrates are available, then protein and amino acids will be used in muscle growth and repair, otherwise protein will be broken down to maintain blood glucose levels.
But don’t worry too much, because this kind of weight loss is temporary once you are back on a normal carbohydrate intake.
The take way here is having sufficient carbohydrates is critical for maintaining muscle mass and then for further gaining muscle mass.