It's very widely accepted that protein is a necessity when aiming to build muscle. After all, muscle is a highly abundant source of amino acids (the building blocks of protein), so it makes sense that in order to build substantial muscle mass, you require an above average intake of protein. Science too confirms this. Yet when it comes to your carbohydrate consumption, there is a lot of confusion on the topic. Do you need carbs to bulk up?
The answer is yes, you absolutely, unequivically require carbohydrates to build muscle. Reducing or even attempting to eliminate carbohydrates from your diet will impede muscle growth and most likely result in muscle loss. Carbohydrates are not only required to build (and maintain) muscle, they are required to facilitate proper brain function and maintain energy levels.
The question now becomes - if amino acids (which form proteins) are a primary constituent of muscle tissue, why are carbs necessary if they do not play a direct role in the structure of a muscle fibre? Let's consider why.
Protein synthesis is the act of creating proteins. When muscles are developing, protein synthesis is occurring by connecting amino acids together into proteins and thus into muscle cells. This is what causes muscle growth, or hypertrophy. In order for this to happen, muscle cells must be able to source amino acids from the blood stream. This is not possible without the presence of insulin, a hormone secreted by the pancreas. Insulin acts as a blood glucose regulator. In order to prevent blood sugar levels from rising too high and becoming dangerous, insulin is secreted to reduce blood glucose levels.
Now the question becomes, if hypertrophy requires amino acids, and amino acid uptake is only possible with the presence of insulin, how then do we increase insulin levels?
Upon ingesting carbohydrates, our body's attempt to break them down into glucose, a simple sugar. Too much glucose in the blood stream can lead to hyperglycemia, so insulin comes along to maintain a healthy blood glucose level.
Ultimately, eliminating any nutrient from your diet is a mistake. Proteins, carbs and fats are all required for optimal muscle development. Removing carbs is a big mistake for anyone seeking to gain muscle tissue.