Weight Loss Evidence

Evidence map

Protein: what the evidence base looks like

11 publications, 4 of them trials and 4 syntheses. This page describes the shape of that literature rather than summarising its conclusions.

Updated 4 min read 11 citations

What the evidence on protein is made of Of 11 publications on this topic, the breakdown by study type: 4 meta-analysis, 4 randomised trial, 3 review. 443meta-analysis (4)randomised trial (4)review (3)
11 publications, by study type. Volume is not strength — the same count can be a settled question or a pile of commentary, and which one it is depends almost entirely on this breakdown. Harvested from PubMed and Crossref; publication type as recorded by the source.

What this literature is made of

The synthesis is ahead of the primary literature here — reviews and meta-analyses drawing on a modest number of underlying studies. Treat confident conclusions with the caution the sample size deserves.

The distinction that matters most is between synthesis and primary research. A meta-analysis pools trials and is the closest thing to a settled answer a field produces. A narrative review is one group's reading of the same material and can be selective without being dishonest. Counting them together, which most citation counts do, obscures exactly the thing you want to know.

When the protein literature was published Publication years for the 11 papers on this topic, grouped into bands from before 2015 through to 2023 onwards. 2020-20224 papersBefore 20153 papers2015-20192 papers2023 onwards2 papers
Still active. The most recent paper here is from 2025, so this is a field where an answer written today may not hold for long. Publication years as recorded by PubMed and Crossref.

How this page is built

Everything above is computed from the citations this site harvested from PubMed and Crossref, not written by hand. When the weekly harvest finds a new paper on this topic, these counts change and the characterisation changes with them. That is the point: a hand-written claim about how strong an evidence base is starts decaying the day it is written.

Publication type is taken as the source records it. That is imperfect — journals label inconsistently, and a paper indexed as a "review" may be a systematic one — so treat the bands as approximate. They are accurate enough to distinguish a trial literature from a commentary literature, which is the distinction that matters.

The strongest work on this topic

Ordered by study design first, then recency. The full set is listed in the references below.

  1. Effect of Whey Protein Supplementation in Postmenopausal Women: A Systematic Review and Meta-Analysis — Kuo YY, Chang HY, Huang YC et al., 2022, meta-analysis
  2. Dietary protein and appetite sensations in individuals with overweight and obesity: a systematic review — de Carvalho KMB, Pizato N, Botelho PB et al., 2020, systematic review
  3. Effects of Dietary Protein Quantity on Bone Quantity following Weight Loss: A Systematic Review and Meta-analysis — Wright CS, Li J, Campbell WW, 2019, meta-analysis
  4. Protein leverage and energy intake — Gosby AK, Conigrave AD, Raubenheimer D et al., 2014, meta-analysis
  5. Similar effects between animal-based and plant-based protein blend as complementary dietary protein on muscle adaptations to resistance training: findings from a randomized clinical trial — Santini MH, Erwig Leitão A, Mazzolani BC et al., 2025, randomised controlled trial
  6. A Randomized Controlled Crossover Lifestyle Intervention to Improve Metabolic and Mental Health in Female Healthcare Night-Shift Workers — Robinson LA, Lennon S, Pegel AR et al., 2025, randomised controlled trial
  7. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial — Longland TM, Oikawa SY, Mitchell CJ et al., 2016, randomised controlled trial
  8. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial — Pasiakos SM, Cao JJ, Margolis LM et al., 2013, randomised controlled trial
  9. Weight Loss Strategies and the Risk of Skeletal Muscle Mass Loss — McCarthy D, Berg A, 2021, review
  10. The Effects of High-Protein Diets on Kidney Health and Longevity — Ko GJ, Rhee CM, Kalantar-Zadeh K et al., 2020, review
How much research is there on protein?
11 publications are indexed here, of which 4 are trials and 4 are syntheses.
Does more research mean a stronger conclusion?
No. Composition matters more than volume — five randomised trials support a claim far better than fifty commentaries, and citation counts do not distinguish between them.
How current is this?
The most recent paper indexed here is from 2025. The set is refreshed weekly from PubMed and Crossref.
Why does this page not tell me the answer?
Because summarising a literature into a conclusion requires reading it, and doing that automatically is how confident nonsense gets published. This page tells you how much weight a conclusion could bear; the articles on this site do the interpreting.

References

Every citation below links to the original peer-reviewed record on PubMed or via DOI. Nothing here is a substitute for medical advice.

  1. Effect of Whey Protein Supplementation in Postmenopausal Women: A Systematic Review and Meta-Analysis Kuo YY, Chang HY, Huang YC, et al. · Nutrients · 2022 · Meta-analysis DOIPubMed 36235862Full text
  2. Dietary protein and appetite sensations in individuals with overweight and obesity: a systematic review de Carvalho KMB, Pizato N, Botelho PB, et al. · European journal of nutrition · 2020 · Systematic review DOIPubMed 32648023
  3. Effects of Dietary Protein Quantity on Bone Quantity following Weight Loss: A Systematic Review and Meta-analysis Wright CS, Li J, Campbell WW · Advances in nutrition (Bethesda, Md.) · 2019 · Meta-analysis DOIPubMed 31301138Full text
  4. Protein leverage and energy intake Gosby AK, Conigrave AD, Raubenheimer D, et al. · Obesity reviews : an official journal of the International Association for the Study of Obesity · 2014 · Meta-analysis DOIPubMed 24588967
  5. Similar effects between animal-based and plant-based protein blend as complementary dietary protein on muscle adaptations to resistance training: findings from a randomized clinical trial Santini MH, Erwig Leitão A, Mazzolani BC, et al. · Journal of the International Society of Sports Nutrition · 2025 · Randomised controlled trial DOIPubMed 41059835Full text
  6. A Randomized Controlled Crossover Lifestyle Intervention to Improve Metabolic and Mental Health in Female Healthcare Night-Shift Workers Robinson LA, Lennon S, Pegel AR, et al. · Nutrients · 2025 · Randomised controlled trial DOIPubMed 41228416Full text
  7. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial Longland TM, Oikawa SY, Mitchell CJ, et al. · The American journal of clinical nutrition · 2016 · Randomised controlled trial DOIPubMed 26817506
  8. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial Pasiakos SM, Cao JJ, Margolis LM, et al. · FASEB journal : official publication of the Federation of American Societies for Experimental Biology · 2013 · Randomised controlled trial DOIPubMed 23739654
  9. Weight Loss Strategies and the Risk of Skeletal Muscle Mass Loss McCarthy D, Berg A · Nutrients · 2021 · Review DOIPubMed 34371981Full text
  10. The Effects of High-Protein Diets on Kidney Health and Longevity Ko GJ, Rhee CM, Kalantar-Zadeh K, et al. · Journal of the American Society of Nephrology : JASN · 2020 · Review DOIPubMed 32669325Full text
  11. Dietary protein for athletes: from requirements to optimum adaptation Phillips SM, Van Loon LJ · Journal of sports sciences · 2011 · Review DOIPubMed 22150425