Journal Watch 7/5/2025

Welcome to our weekly round-up of the latest bariatric and obesity-related papers published in the medical literature. As ever, we have looked far and wide to give you an overview of papers including an increase in adolescent BMS procedures, trends in BMS revisions, the impact of lifestyle change programme prior to BMS, protein supplementation does not influence overall BMI and lean body mass and reported hospitalisations for total joint replacement after BMS, and more (please note, log-in maybe required to access the full paper).

Metabolic and Bariatric Surgery Utilization in the Era of Glucagon-Like Peptide-1 Receptor Agonists among Adolescents versus Adults

The number of bariatric surgeries for adolescents increased by 15% in the US between 2021 and 2023, according to a study led by UT Southwestern Medical Center researchers.

Writing in The Journal of Pediatrics, the researchers gathered data on how many adolescents (ages 13-19) and adults received BMS between 2021 and 2023, the years before, during, and after GLP-1RAs became FDA-approved for adolescents. They also collected demographic information on these patients.

Their findings showed BMS increased among adolescents over this time span, from 1,376 patients in 2021 to 1,581 in 2023. The mean age decreased slightly during this time, from 17.91 to 17.79. Gastric sleeve operations dominated these procedures, representing more than 86% of all the surgeries performed.

Although BMS rose among adults between the first two years, from 209,829 procedures in 2021 to 229,159, they dropped to 216,323 in 2023. The researchers hypothesised that this decrease was due to more adult patients opting to take GLP-1RAs instead of having surgery.

Looking to the future, treatment for severe obesity is likely to involve BMS and weight-loss medications as well as lifestyle support to achieve long-term health, researchers noted.

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Trends in bariatric surgery revisions: a 25-year single-institution experience

Revisional bariatric surgery (RBS) are increasingly common, highlighting the chronicity of obesity and the need for long-term management, researchers from Mayo Clinic, Rochester, MN, have reported. Their study describes trends in BMS revisions at their institution over 25 years.

Reporting in Surgical Endoscopy, a total of 667 patients underwent a first-time bariatric surgery revision; 364 (54.5%) performed surgically and 303 (45.5%) endoscopically. There was a noticeable trend toward endoscopic revisions indicated for weight-related indications, particularly over the past decade. For surgical revisions, Roux-en-Y gastric bypass (RYGB) was the most revised primary BMS operation overall, surpassed by sleeve gastrectomy (SG) in recent years. A further 14.9% of patients required more than one bariatric revision procedure.

Transoral endoscopic revisions were primarily used for weight-related indications after RYGB, with many other indications managed exclusively through surgery.

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The effect of preoperative body weight loss on 5-year bariatric surgery outcomes

Researchers from Hospital Clinic, Barcelona and the Centro de Investigación Biomédica en Red de Obesidad y Nutrición (CIBEROBN), Barcelona, Spain, have found that the current evidence suggests that preoperative total body weight loss (TBWL) - following a structured 6-month lifestyle change programme (LCP) - provides short-term benefits, and may also be the case for TBWL in the long-term.

Writing in the International Journal of Obesity, the study aimed to evaluate the effect of preoperative TBWL following LCP.  In total, 165 patients met the inclusion criteria; 59 in the LCP group and 106 in the control group (CG). At surgery, the LCP group showed significant weight reduction (–5.9 kg vs. –0.72 kg in controls, p=0.008) and their BMI was significantly lower (46.55 vs. 49.47 kg/m², p=0.002). Postoperatively, weight-related outcomes [BMI and TBWL] were better in the LCP group at one and five years. Additionally, patients achieving a preoperative TBWL >5% demonstrated a significantly lower weight and BMI, along with a higher postoperative TBWL.

Further research is needed to fully elucidate the role of preoperative TBWL in comorbidity resolution in BS patients, the researchers added.

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The effects of protein supplementation on body composition after bariatric surgery: a systematic review and meta-analysis of randomized controlled trials

Although protein supplementation may improve weight and some body composition metrics, it does not influence overall BMI and lean body mass, investigators from Tehran University of Medical Sciences, Tehran, Iran, have found.

Reporting in the journal Obesity, they explored the effect of protein supplementation on anthropometric measures and body composition in patients after MBS.

This systematic analysis included ten trials and there was a statistically greater change in weight (WMD, −1.31 kg, 95% CI: −1.93 to −0.69, p<0.001; Grading of Recommendations Assessment, Development, and Evaluation [GRADE] = moderate), muscle mass (WMD, 1.33 kg, 95% CI: 0.1 to 2.57, p=0.035; GRADE = low), fat-free mass (WMD, 1.74 kg, 95% CI: 0.46 to 3.01, p=0.01; GRADE = low), and fat mass (WMD, −3.91 kg, 95% CI: −4.10 to −0.59, p=0.01; GRADE = low) in the protein group compared to the control group. However, protein supplementation did not significantly change BMI and lean body mass.

The researchers added that more research is needed to recommend protein supplementation after MBS.

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The relationship between bariatric surgery and risk of hip or knee replacement in severe osteoarthritis is obesity class–specific

Researcher from Lille University Hospital, Lille, France, have reported hospitalisations for total joint replacement (TJR) following bariatric surgery was associated with an increase of 25% in patients with BMI ≥40 kg/m2, whereas it was associated with a decrease of 15% in patients with BMI <40 kg/m2, in France.

Writing in SOARD, they evaluated the relationship between the risk of TJR and the fact of having undergone bariatric surgery in people living with obesity (PwO). In total, 160,773 patients who had undergone bariatric surgery (mean age 40.8 years, 79.5% female) and 160,773 matched controls were identified. The most frequent surgical technique was sleeve gastrectomy (72.2%), followed by gastric bypass (27.8%). The average follow-up was 4.7 years. An increase in the overall risk of TJR, with a hazard ratio (HR) of 1.09 (95% confidence interval [CI], 1.03–1.15), was observed.

Depending on obesity class, patients with body mass index (BMI) <40 kg/m2 had a lower risk of TJR (HR = .85; 95% CI, .78–.93), whereas a higher risk was observed in patients with BMI ≥40 kg/m2 (HR = 1.25; 95% CI, 1.16–1.34).

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