Protein Intake and Muscle Mass – What’s the Deal?

April 6, 2021

There are a number of theories about losing fat and gaining muscle mass. A common misconception is that increasing protein intake will increase muscle mass. Muscle is comprised of protein, but only about 22%.

The only way to truly build muscle is by working, not eating.  Working the muscle to muscular overload through strength and resistance training is what boosts growth. When you lift weights, small tears occur in the muscle and as they repair and heal, the muscle grows. Proper fuel and energy are important, as they are needed to support the training efforts to promote hypertrophy (growth in size) of the muscle, but simply ingesting protein will not make a muscle grow larger.

What to Eat to Build Muscle:

Carbohydrates are the primary fuel for working muscles. If carbohydrate levels are low, workouts are inhibited as a result of early physical and mental fatigue.  Effort is often decreased and the result is compromised performance. If the body does not have enough carbohydrate for fuel, it will use whatever energy source is available.

Protein contributes minimally to energy needs (5 to 15%), and it is an inefficient energy source.  However, if energy needs are not met by carbohydrate, the body will turn to protein for energy. Protein can be biochemically broken down into carbohydrate, and the body will use dietary and muscle protein to provide for the lack of energy from carbohydrate.  It is important to note that this process burns energy and does not improve performance, and thus, is not the optimal way to build muscle.  In fact, excess protein serves to dehydrate the body. When the body is dehydrated by as little as 5%, workouts are compromised.

In the end, if someone is consuming extra protein in an effort to build muscle, just the opposite may happen. The muscle mass that someone is trying to build will likely not increase, and instead, it may be broken down.

The protein needs for someone who wishes to increase muscle mass generally range from 1.2 to 2 grams/kilogram of body weight per day. This is 0.4 to 1.2 gm/kg above the RDA. However, there are other factors that affect protein requirements, such as individual differences. Provided that the protein needs are met (and with 10-15% of calories consumed coming from protein, they will be!), carbohydrate needs are met, and sufficient calories for weight gain are consumed, muscle mass will increase.

The Main Lesson:

Extra protein and supplements are not necessary to build muscle and they may actually do more harm than good.