Have you ever wondered if you can be vegan and still grow muscle at the same rate as an omnivore (someone who eats both meat and vegetables)? I’m sure a lot of people have. And to be fair it may be arguable that the quality of the protein source or more specifically the amino acid profile of the food source when coming from vegan food is less desirable than that of an animal based protein. The question is, though, can you still grow muscle when not eating any animal products? Or more specifically is eating a vegan diet considered optimal for muscle growth?
The one thing we do know about non-animal derived proteins is that there are no known ‘complete’ proteins, whereby their amino acid profile, more specifically their Essential Amino Acid (EAA) profile, as a single food type are considered complete or optimal for ensuring the highest protein bioavailability (how well its assimilated). In essence, the amino acid profile is missing an important link and in order for you to fix it, you need to couple varying types of vegan proteins into one meal so the amino acid profile is complimentary.
For example, by consuming a legume alongside a grain or a fruit alongside a sprout, you are essentially fortifying one food groups lack of amino acids, with another that is high in the missing links, and in doing so can create a meal that is now complete in its amino acid profile.
But is food coupling enough?
Maximal Protein Synthesis (MPS) refers to the maximum amount of protein that can be utilised after the consumption of a protein source, which can be referred to as a maximal muscle growth response as well, and is highly controlled by 2 factors:
- The amount of Leucine (Branched Chain Amino acid) per meal
- Available substrate in the bloodstream (ATP)
The top 3 factors to be considered when trying to achieve MPS are:
- Consume 2.5g of Leucine from a food-based protein in 1 serve
- MPS cannot be re-stimulated by a protein based food source within 3 hours of your previous meal. Eating a protein source from whole food every 4-5 hours is optimal
- Re-stimulating MPS between meals can only be achieved through BCAA/EAA consumption or via the ingestion of +30g of carbs or more
Leucine is an EAA that must be consumed via the diet and plays a critical role in signalling a muscle growth response and is the key to achieving MPS. In order for this to occur, according to the research of Dr Layne Norton (1), we require a minimum dosage of 2.5g per meal. Outside of vegan sources, chicken, beef, fish, cheese and whey protein can all achieve this with 130g of cooked meat or 35g of whey, however only limited vegan sources can, with soybeans and pumpkin seeds being some of the highest at 3.2g and 2.4g of Leucine per 100g respectively.
However, we can’t expect you to only eat pumpkin seeds to achieve a muscle growth response. Similarly, we also need to consider your daily macronutrient intake (protein, carbs, fats), as we know according to Eric Helms Pyramid of importance that the most important factor for body composition control is calories, followed by macronutrients, micronutrients, nutrient timing and then supplements.
The other thing you have to consider when consuming a vegan based diet that is attempting to stimulate MPS using whole foods is their total calories and other macronutrients per serve.
Macronutrients per 100g
|Pumpkin Seeds||Rump Steak (fully trimmed raw)|
|24.4g Protein||20.2g Protein (3.1g Leucine)|
|45.6g Fat||4.6g Fat|
|13.7g Carbs||0g Carbs|
Source: Food Standards Australia
As you can see the pumpkin seeds are a phenomenal protein source, providing more than the lean meat per 100g, however, they also contain 4x the calories at the same serving size and 10x the fat in grams.
And therein lies the issue a vegan diet may face. It is extremely difficult to maintain an optimal calorie/macronutrient balance with adequate amounts of Leucine and the muscle building BCAA’s to ensure optimal muscle growth or even muscle retention for those not looking to grow.
But not to worry, further down I will be showing you how you can supplement your diet to fortify your meals so that they can achieve MPS.
The second variable to consider when trying to maximise MPS via your diet is substrate availability and nutrient timing, whereby it is optimal to consume larger, less frequent dosages of protein in your major meals and rely on your carbohydrate snacks in between your major meals.
By consuming carbohydrate only snacks in between meals, has been shown to increase ATP availability, which has the ability to re-stimulate MPS above what protein consumption would during the time whereby MPS is falling back into its refractory period (2).
Understanding this will allow you to apply your knowledge to dietary intake and nutrient timing.
Knowing that MPS can only be achieved through the single consumption of a food source containing 2.5g of Leucine or more every 4+ hours, how do we achieve this using vegan protein sources when we know they are calorie laden at the serving size required to achieve this?
Looking at Eric Helms pyramid of importance again we can see that the primary concern for body composition is calories, followed by macronutrients and then micronutrients, nutrient timing and finally supplementation. However given the primary limitation of vegan dieting is adequate protein consumption, while maintaining the calorie balance, the supplement portion of the pyramid has a far greater importance due to its ability to fortify the macronutrients of a vegan diet.
So whether you are looking to ensure MPS is achieved for muscle growth optimisation or are simply trying to prevent muscle breakdown, I would recommend the following approach to dieting consumed as 3 meals during the day.
- Meal - Primary protein source + 1 serve of BCAA's
- Snack – Carbohydrate source
Eating this way will ensure MPS is achieved 3-6x a day by reaching your Leucine per meal threshold, of which MPS will be stimulated. Following this, carbohydrates can then be consumed and will further provide a follow-up stimulation of MPS in between meals and will give you the maximum amount of muscle growth stimulus you can achieve in a single day.
You are only limited by what you know! Just because you or a friend are following a vegan diet, does not mean you have to be limited in your ability to achieve maximum muscle growth.
By utilising nutrient timing to fortify your diet and provided your calorie consumption is accurate, theoretically your potential to grow muscle is on the same level of that of someone who consumes meat for their protein sources.
Layne E. Norton; Donald K.Layman; Piyawan. Bunpo; Tacy G.Anthony; Diego V.Brana; Peter J.Garlick. (2009).The Leucine Content of a Complete Meal Directs Peak Activation but Not Duration of Skeletal Muscle Protein Synthesis and Mammalian Target of Rapamycin Signaling in Rats., The American Institute of Nutrition. 139(6). Pp 1103-1109.