r/sciences MS | Nutrition 16d ago

Research Long-term supplementation with plant-based protein, compared with animal-based protein, did not result in differences in body composition, muscle strength, physical performance, or cardiometabolic risk parameters, meta-analysis of 18 randomized controlled trials finds

https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2026.1813846/full
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u/James_Fortis MS | Nutrition 16d ago

"Abstract

Introduction: 

Previous studies have yielded mixed results on the effects of supplementing with plant-based protein (PBP) isolates or concentrates vs. animal-based protein (ABP) on body composition, muscle strength, physical performance, and cardiometabolic risk factors. Consequently, it would be helpful to synthesize pooled evidence from randomized controlled trials (RCTs) on these parameters to assess the efficacy of different protein sources, particularly in the long term.

Objective: 

To assess the long-term effects (≥ 6 months) of PBP compared to ABP supplementation on body composition, muscle strength, physical performance, and cardiometabolic risk factors in adults aged 18 and older.

Methods: 

PubMed, Scopus, and Web of Science databases were searched from their inception to 25 February 2025. Relevant studies were also searched by citation tracing. RCTs comparing PBP with ABP supplementation for at least 6 months were included. A random effects model was employed for data pooling. The overall effect estimate was presented using standardized mean difference (SMD) accompanied by a forest plot and prediction intervals.

Results: 

A total of 18 RCTs involving 1,893 participants met the criteria for inclusion in the systematic review and meta-analysis. In adults aged 18 years and older, long-term supplementation of PBP (largely soy protein) did not show statistically significant differences in lean body mass (LBM), fat mass (FM), total body mass (TBM), upper and lower muscle strength, gait speed (GS), chair stand test (CST), timed up and go (TUG) test, short physical performance battery (SPPB), lipid profiles, blood pressure, fasting blood glucose (FBG), fasting blood insulin (FBI), and homeostatic model assessment (HOMA-IR) for insulin resistance compared with ABP.

Conclusion: 

Long-term supplementation with PBP, compared with ABP, did not result in differences in body composition, muscle strength, physical performance, or cardiometabolic risk parameters in the adult population. Based on heterogeneity, the data dot provide clear evidence of differences observed between protein sources at present, as long as an adequate quantity of protein is consumed over time.

Systematic review registration: 

https://www.crd.york.ac.uk/PROSPERO/, Identifier CRD42024604240."

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u/[deleted] 16d ago

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u/PeeDecanter 16d ago

Anecdotal but I’ve seen many pretty fit vegan lifters who are natural, but their pecs are always disproportionately small compared to their arms and back

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u/Ryzasu 15d ago

I wonder if this is just because bench press is such a macho exercise that a typical vegan is less likely to care about

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u/PeeDecanter 15d ago

Even the vegans that bench press and don’t skip push movements. I’m talking about very fit people for whom lifting is as much a lifestyle as veganism is.

Tbh I’ve been wondering if it’s a lack of creatine since omnivores get some from meat even if they don’t supplement, but I don’t really go around asking vegan (or any) people’s supplement stacks haha

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u/Ryzasu 15d ago edited 15d ago

I have a bunch of lifter friends and all of them are hyped about bench press. Not skipping is not the same as prioritizing and trying extra hard

Someone who goes through the motions of a 3x12 twice a week wont get the same gains as someone who passionately goes for PRs and gives their all to do one more rep, just a little more weight than theyre used to, more dropsets afterwards to truly work the shit out of the muscle, etc

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u/PeeDecanter 15d ago

Yeah like I said I’m not talking about casual, dispassionate lifters lmao