What Recent Trials Show About Protein Powder
Protein powder research has evolved meaningfully over the past decade, and some earlier assumptions have been revised by more recent, better-controlled trials. This update covers the key findings that have emerged from current research on protein powder — including shifts in consensus on dosing, the timing debate, and comparisons between protein sources.
Shifts in Consensus: Daily Protein Needs
The long-standing recommendation of roughly 0.8 g/kg/day as an adequate protein intake was based on nitrogen balance studies in sedentary adults. For people engaged in regular resistance training or endurance exercise, the evidence now supports considerably higher intakes.
Morton et al. (2018) conducted a systematic review and meta-analysis of 49 studies including over 1,800 participants, finding that protein supplementation significantly augmented gains in fat-free mass and one-repetition maximum strength, with the effect plateau observed at approximately 1.62 g/kg/day across the population studied (Morton et al., 2018). Above this level, additional protein did not further increase muscle gain on average.
This does not mean 1.62 g/kg/day is a hard cap for everyone — individual variation exists, and older adults may benefit from higher intakes due to anabolic resistance.
The Timing Debate
The concept of an "anabolic window" — a brief post-workout period during which protein intake is critically important — has been substantially revised. Schoenfeld et al. (2013) reviewed the timing evidence and concluded that total daily protein intake is more important than timing for most exercisers who are eating adequate protein across the day (Schoenfeld et al., 2013).
Practical implication: if you are hitting your daily protein target from food plus supplemental protein powder, the exact timing of the shake matters less than previously believed. That said, for athletes training in a fasted state or those who have very long gaps between meals, protein close to training remains practically useful.
Still-Open Questions
Protein Source Comparisons
Whey protein remains the most extensively studied supplemental protein source, with well-documented superior leucine kinetics compared with many plant proteins. However, the gap between animal and plant proteins may be narrower than older literature suggested when total daily intake is matched.
Van Vliet et al. (2015) noted that differences between protein sources are attenuated when intakes are equated and dietary variety provides the full essential amino acid spectrum (Van Vliet et al., 2015). The practical implication is that plant protein powders can support muscle protein synthesis when used in adequate amounts and when the amino acid profile is complemented across the diet.
Protein and Older Adults
Anabolic resistance in older adults means that the dose required to maximally stimulate muscle protein synthesis is higher per meal than in younger individuals. Whether standard protein powder supplementation fully offsets this is still an active research area.
What It Means Practically
- Total daily protein intake matters more than the specific brand or form of supplement
- Whey and casein remain well-evidenced choices for muscle support; plant proteins are a viable alternative when used thoughtfully
- Post-workout timing is less critical than total daily intake for most exercisers
- Older adults and those in energy deficit may benefit from slightly higher protein targets
At maxfit.ee, popular choices include Optimum-nutrition Gold Standard 100% Whey 900g Maasikas, BIOTECHUSA ISO WHEY ZERO 908g Šokolaad, MyProtein Impact Casein 2.5kg Šokolaad, and BIOTECHUSA Vegan Protein 500g Metsaviljad for plant-based needs.
Bottom Line
Protein powder is among the most evidence-supported supplement categories. The science supports its use as a convenient way to meet daily protein targets. The most important variable is total daily intake matched to your goals and activity level — not the specific product or exact post-workout timing.
FAQ
Is plant protein powder as effective as whey?
In most practical settings, when total daily protein is adequate and the amino acid profile is balanced across meals, plant protein powders support muscle protein synthesis effectively. Studies directly comparing matched intakes show smaller differences than older literature implied. For maximal per-serving leucine delivery, whey retains an advantage.
How much protein powder per day is too much?
For healthy adults with normal kidney function, high protein intakes have not been shown to cause kidney damage. The practical question is whether additional protein continues to add benefit — the evidence suggests muscle gain plateaus at total intakes around those cited above. Beyond that, excess protein contributes calories without additional muscle-building benefit.
Does protein powder cause bloating?
Some people experience GI discomfort from whey concentrate due to lactose content. Whey isolate and hydrolysate have much lower lactose and are typically better tolerated. Plant proteins can also cause bloating in some individuals. If bloating is an issue, try a different form or source.
References
Morton, R. W., Murphy, K. T., McKellar, S. R., Schoenfeld, B. J., Henselmans, M., Helms, E., Aragon, A. A., Devries, M. C., Banfield, L., Krieger, J. W., & Phillips, S. M. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 52(6), 376-384. https://pubmed.ncbi.nlm.nih.gov/28698222/
Schoenfeld, B. J., Aragon, A. A., & Krieger, J. W. (2013). The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. Journal of the International Society of Sports Nutrition, 10(1), 53. https://pubmed.ncbi.nlm.nih.gov/24299050/
Van Vliet, S., Burd, N. A., & van Loon, L. J. (2015). The skeletal muscle anabolic response to plant- versus animal-based protein consumption. Journal of Nutrition, 145(9), 1981-1991. https://doi.org/10.3945/jn.114.204305
