Weight Loss Evidence

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Bariatric: what the evidence base looks like

8 publications, 0 of them trials and 6 syntheses. This page describes the shape of that literature rather than summarising its conclusions.

Updated 3 min read 8 citations

What the evidence on bariatric is made of Of 8 publications on this topic, the breakdown by study type: 6 meta-analysis, 1 review, 1 other. 611meta-analysis (6)review (1)other (1)
8 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 bariatric literature was published Publication years for the 8 papers on this topic, grouped into bands from before 2015 through to 2023 onwards. 2023 onwards6 papers2015-20191 papersBefore 20151 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. ​​Long-Term Outcomes in Sleeve Gastrectomy versus Roux-en-Y Gastric Bypass: A Systematic Review and Meta-Analysis of Randomized Trials — Monteiro Delgado L, Fabretina de Souza V, Fontel Pompeu B et al., 2025, meta-analysis
  2. Position statement and guidelines about Endoscopic Sleeve Gastroplasty (ESG) also known as "Endo-sleeve" — Baratte C, Sebbag H, Arnalsteen L et al., 2025, clinical guideline
  3. Long-Term Results of Bariatric Surgery in Adolescents with at Least 5 Years of Follow-up: a Systematic Review and Meta-Analysis — Wu Z, Gao Z, Qiao Y et al., 2023, meta-analysis
  4. Long-Term Outcomes of Iron Deficiency Before and After Bariatric Surgery: a Systematic Review and Meta-analysis — Xia C, Xiao T, Hu S et al., 2023, meta-analysis
  5. Long-Term Outcomes After Bariatric Surgery: a Systematic Review and Meta-analysis of Weight Loss at 10 or More Years for All Bariatric Procedures and a Single-Centre Review of 20-Year Outcomes After Adjustable Gastric Banding — O'Brien PE, Hindle A, Brennan L et al., 2019, meta-analysis
  6. Robotic bariatric surgery: a systematic review — Fourman MM, Saber AA, 2012, systematic review
  7. Long term outcomes of metabolic/bariatric surgery in adults — Courcoulas AP, Daigle CR, Arterburn DE, 2023, review
  8. Long-Term Outcomes of Medical Management vs Bariatric Surgery in Type 2 Diabetes — Courcoulas AP, Patti ME, Hu B et al., 2024, journal article
How much research is there on bariatric?
8 publications are indexed here, of which 0 are trials and 6 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. ​​Long-Term Outcomes in Sleeve Gastrectomy versus Roux-en-Y Gastric Bypass: A Systematic Review and Meta-Analysis of Randomized Trials Monteiro Delgado L, Fabretina de Souza V, Fontel Pompeu B, et al. · Obesity surgery · 2025 · Meta-analysis DOIPubMed 40622470
  2. Position statement and guidelines about Endoscopic Sleeve Gastroplasty (ESG) also known as "Endo-sleeve" Baratte C, Sebbag H, Arnalsteen L, et al. · Journal of visceral surgery · 2025 · Clinical guideline DOIPubMed 39794164
  3. Long-Term Outcomes of Iron Deficiency Before and After Bariatric Surgery: a Systematic Review and Meta-analysis Xia C, Xiao T, Hu S, et al. · Obesity surgery · 2023 · Meta-analysis DOIPubMed 36701012
  4. Long-Term Results of Bariatric Surgery in Adolescents with at Least 5 Years of Follow-up: a Systematic Review and Meta-Analysis Wu Z, Gao Z, Qiao Y, et al. · Obesity surgery · 2023 · Meta-analysis DOIPubMed 37115416
  5. Long-Term Outcomes After Bariatric Surgery: a Systematic Review and Meta-analysis of Weight Loss at 10 or More Years for All Bariatric Procedures and a Single-Centre Review of 20-Year Outcomes After Adjustable Gastric Banding O'Brien PE, Hindle A, Brennan L, et al. · Obesity surgery · 2019 · Meta-analysis DOIPubMed 30293134Full text
  6. Robotic bariatric surgery: a systematic review Fourman MM, Saber AA · Surgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery · 2012 · Systematic review DOIPubMed 22579735
  7. Long term outcomes of metabolic/bariatric surgery in adults Courcoulas AP, Daigle CR, Arterburn DE · BMJ (Clinical research ed.) · 2023 · Review DOIPubMed 38110235
  8. Long-Term Outcomes of Medical Management vs Bariatric Surgery in Type 2 Diabetes Courcoulas AP, Patti ME, Hu B, et al. · JAMA · 2024 · Journal article DOIPubMed 38411644Full text