How Often Should You Consume Protein to Build Muscle?

People have discussed the interrelationship between protein consumption and muscle-building for years. What do we actually know about protein timing as it relates to our ability to optimally build muscle? In all honesty, despite what you may have heard, the science of nutrition and muscle-building is still in its infancy, and much of what we claim "to know" about these topics is based upon speculation and educated guesses. Nevertheless, we are not totally in the dark.

Optimal Amount of Protein per Meal

Before we start to discuss the "how-often" of protein consumption, it seems appropriate to first figure out the "how-much." Paddon-Jones et al. demonstrated that 15 grams of essential amino acids was sufficient to stimulate protein synthesis [1], and research by Tipton et al. seems to suggest that an amount beyond 15 grams is not necessary [2]. Further research by Dr. Layne Norton et al. indicates that the amino acid leucine may be a particularly important up regulator of protein synthesis [3]. The amount of leucine required is about 2-4 grams (the dose depends on the size of the person). The amount of whole food animal protein required to get 15 grams of essential aminos, and more importantly the required 2-4 grams of leucine, varies depending upon the source. Below is a chart of various sources of animal protein and the amount of each source required in order to get the optimal amount of leucine [4]:

As you can see, the amount of leucine present in various protein sources is not uniform.

Based on the above, we could generalize and say that anywhere between 30-40g of protein (animal protein!) would be required to maximally stimulate protein synthesis. Consuming carbohydrate alongside this protein may likely serve to down regulate protein degradation as well [5].

Optimal Frequency of Protein Consumption

So now that we know the threshold quantity of protein required to maximally stimulate protein synthesis, let's further assess how often you should consume protein. Let me first say that much of what is said in muscle-building magazines regarding the necessity of consuming ridiculous amounts of protein every 2-3 hours is premised upon supplement companies' drive to sell their products. I think we can all agree that eating 30 grams of protein every other hour is incredibly inconvenient--hence why supplement companies are so adamant about making you believe that you have to consume protein so frequently. Protein supplements are by far a more convenient way to get in your protein requirements than are grilled chicken breasts or cuts of beef when you're trying to eat protein every 2-3 hours. 

Of course, the recommendation that you ought to eat protein every 2-3 hours is not entirely unfounded. Research has shown that leucine maximally stimulates protein synthesis for 2 hours, after which time protein synthesis returns to basal value [6]. However, I should note that this 2 hour figure is only relevant once leucine has reached the blood stream. If we factor in digestion, the peak increase in protein synthesis would occur after 3 hours; not 2. Nevertheless, as you can see, the notion that consuming protein every 2-3 hours maximally stimulates protein synthesis does seem reasonable--except for the fact this method doesn't actually work.

As it turns out, once protein synthesis has been maximally stimulated and has reached its peak at 2-3 hours post absorption, it cannot be re-stimulated for another 1-2 hours. In other words, eating the required 30-40 grams of protein every 2-3 hours is too frequent. In actuality, the better frequency (at least in relation to the short-term physiological effects of protein consumption) is more like every 4-5 hours. Protein synthesis cannot be up regulated any more often than this frequency.

Putting Things Together

Let's recap: (1) 30-40 grams of protein is sufficient to maximally stimulate protein synthesis, and (2) consuming this 30-40 grams of protein more frequently than every 4-5 hours is unnecessary. In practical terms, a potential protein timing protocol (and this is what I do currently) might entail eating at least 30-40g of animal protein for breakfast, lunch, dinner, and before bed. If you were to feel the need to consume snacks between these meals, I would advise making these snacks low protein since any additional protein consumed within the 4-5 hours between meals would do nothing to further stimulate muscle anabolism (unless of course you're having issues with hunger, in which case a high protein snack might be a good idea for satiety and psychological purposes).

There is no need to consume 6-8 high protein meals every day, day after day in order to build muscle. Eat a high protein breakfast, lunch, and dinner, and maybe a high protein meal before bed, and keep getting stronger in the gym. That's all there is to it.