“Bro-science” has long claimed animal proteins are essential for serious gains. This seems to make sense when you consider that foods like beef, chicken, and eggs deliver a dose of protein and an amino acid profile that, on paper, is superior to what you would get from a can of beans. For this reason, the common belief is that feasting mostly on plants is a recipe for deflated pecs.
Well, the latest research suggests that we can forgo the steak and whey and still pack on more lean mass. Reassurance that those choosing plant-based diets can reach their fitness goals without compromise.
Some of the best data to date regarding plant protein and muscle-building comes from a recent trial published in the journal Medicine & Science in Sports & Exercise. It enrolled 40 young adults and randomized them to either a vegan or an omnivore diet. The study participants performed three weightlifting sessions over nine days, and, importantly, researchers provided all their meals to them. Both groups consumed the same amount of protein daily (roughly 1.1 to 1.2 grams per kilogram of body weight).
Studies that provide participants with their meals are more accurate because they don’t rely on self-reported intake, which is notoriously inaccurate. At the end of the study, scientists biopsied the participants’ muscles, which allowed them to determine rates of protein synthesis. Results showed that the anabolic action of animal versus plant-only dietary patterns were similar as demonstrated by similarities in myofibrillar protein synthesis rates.
An outcome that contradicts long-held beliefs about animal protein superiority with respect to packing on more muscle. The study authors did note that resistance exercise may have enhanced the anabolic response to both dietary patterns, potentially eliminating quality differences between animal and plant proteins that might exist in people who are not training.
Historically, one of the main reasons that people believed plant protein was inferior was based on results of studies that analyzed the impact of a single meal, or a single protein (i.e., whey vs. pea), over a period of just a few hours. Improved studies such as this look at the whole dietary pattern over several days.
The researchers also tested whether protein distribution throughout the day mattered when it came to muscle protein synthesis. Half the participants in each diet group consumed their protein in three uneven meals (10%, 30%, and 60% of daily protein), while the other half spread their protein intake evenly across five meals (20% each). The study found no significant difference in muscle-building between these approaches. Simply put, whether participants ate animal or plant proteins, and regardless of how they timed their protein intake, their muscles produced new proteins at similar rates.
The study also took a look at psychological well-being and found that participants on meat-containing omnivorous diets reported greater feelings of pleasantness, while those on plant-only diets reported higher energy and lower tiredness.
It is worth noting that the study was conducted over a relatively short period (9 days), so long-term effects remain unknown. You can infer only so much from a shorter study, which didn’t measure muscle growth or changes in strength. Future research should track muscle and strength growth changes over several weeks in a population with a wider age range.
Some Take-home Messages from This Research
Yes, you can build just as much muscle on a plant dominated diet as long as you consume enough total protein. This study suggests that 1.2g per kilo body weight can instigate muscle growth, but other research suggests that going up to at least 1.6 grams is most beneficial. This is especially true as we age and our anabolic response to amino acids is diminished.
We need to fret less about certain plant foods having a worse amino acid profile than animal foods as long as a variety of plant-based proteins are consumed in a day to get all the amino acids needed and the necessary amount of total protein.
Precise protein timing and distribution don’t appear to be critical for muscle-building. In other words, if you decided to consume 80% of your protein at a single meal that would be fine as long as it’s part of a dietary pattern where enough total protein is taken in.
Exercise, and particularly resistance training, appears to enhance the body’s ability to use plant-based protein most effectively, minimizing differences between animal and plant sources. If someone was sedentary, there is a chance that animal-based protein would be more effective at maintaining lean body mass. But you can’t just eat heaps of protein without forcing your muscles to progressively work harder and expect to pack on muscle.
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Protein PackPlant Based Power
In general, meat is more protein dense, so you can end up eating significantly more calories to get the same amount of protein from plants. This is why, if you want to eat mostly plants, you need to make sure to include some options that provide more protein for fewer calories. That way you can get all the amino acids you need to maximize muscle growth without going into a calorie excess. Anyways, there are only so many beans a person can eat before their gut explodes.
These plant-based foods make it possible to get 0.72 grams of protein per pound of body weight, a widely accepted figure to hit to optimize training adaptations. This equals 130g of protein for a 180 pound person.
- ½ block tofu (25 grams)
- 3 tbsp hemp seeds (10 grams)
- 1 cup soymilk (8 grams)
- 3 oz tempeh (18 grams)
- 1 cup chickpeas (15 grams)
- 2 scoops plant protein powder (30 grams)
- 2 tbsp peanut butter (7 grams)
- 1 cup quinoa (8 grams)
- 1/2 cup green peas (4 grams)
- 1/4 cup almonds (8 grams)
