Are Carbohydrates Anabolic?

Carbohydrates alone won't stimulate protein synthesis. The increases in protein synthesis observed from eating a meal are most likely due to the dietary protein content of the meal.

- By Layne Norton

There are probably more myths and speculation surrounding carbohydrates than any other macronutrient. Do they make you fat or not? Do you need them for energy or not? Do they increase performance or not? The focus of this article is to establish whether carbohydrates should be considered anabolic. To determine this, we first must define what anabolic is.

Protein Synthesis

Simply put, the definition of anabolic is “of or related to the synthetic phase of metabolism. The synthetic phase of metabolism is protein synthesis, the process by which cells make new protein. Briefly, some signal for growth (hormones, nutrients, etc.) causes an increase in the rate at which new proteins are synthesized within the cell. When this process occurs on a large scale over time in skeletal muscle, it's referred to as skeletal muscle hypertrophy (growth). In order for carbohydrates to be defined as anabolic, there must be conclusive evidence that carbohydrate ingestion increases skeletal muscle protein synthesis.

A common thread in bodybuilding thought is that carbohydrates are anabolic because they increase insulin secretion and insulin is anabolic. There are countless articles written on how insulin increases protein synthesis and decreases protein degradation, making it one of the most anabolic hormones in the body. However, many of these articles base their conclusions on scientific research that was conducted using the wrong populations. You see, insulin is actually a growth hormone. This simply means that the body is most sensitive to the effect of the hormone during the growth process.