HMB for Weight Loss Surgery: Does It Help Muscle?

study PMID: 40326309

Quick Summary: A recent study looked at whether taking HMB supplements after weight loss surgery helps patients keep their muscle mass. The results showed that HMB didn't make a big difference in preserving muscle compared to just taking protein supplements.

What The Research Found

Researchers wanted to see if adding HMB (a supplement) to the diet of people who had weight loss surgery would help them keep their muscle. They found:

HMB didn't significantly help people keep more muscle mass compared to those who took protein supplements without HMB.

People taking HMB had slightly better levels of a protein called prealbumin, which is linked to better nutrition.

Exercise was important for losing fat, but it didn't seem to help much with keeping muscle in this study.

Study Details

Who was studied: 24 adults (mostly women) who had weight loss surgery.

How long: The study lasted for 3 months after surgery.

What they took: Some people took protein supplements with HMB (3 grams per day), while others took protein supplements without HMB.

What This Means For You

If you've had weight loss surgery, this study suggests that adding HMB to your protein supplements might not be the key to keeping your muscle. Here's what you can focus on:

Protein is key: Make sure you're getting enough protein in your diet.

Move your body: Regular exercise is important for overall health and can help with fat loss.

Talk to your doctor: Discuss the best diet and exercise plan for you after surgery.

Study Limitations

It's important to keep these things in mind:

Small study: The study only included a small number of people, so the results might not apply to everyone.

Mostly women: The study mostly included women, so the results might be different for men.

Short time: The study only looked at the first 3 months after surgery.

Other factors: The study didn't look at how HMB works in the body.

Key Findings

This 2025 study evaluated whether HMB supplementation improves nutritional outcomes in patients undergoing bariatric surgery. Key results showed:
- No significant differences in weight loss (17.5 ± 1.3 vs. 19.1 ± 1.7 kg), lean mass preservation (3.07 ± 1.7 vs. 3.06 ± 1.36 kg), or muscle function (dynamometry) between HMB-supplemented and control groups.
- Higher prealbumin levels in the HMB group (21 ± 1 vs. 18 ± 0.8 mg/dL, p = 0.04), suggesting potential benefits for short-term nutritional status.
- Physical activity significantly influenced fat mass loss but not lean mass preservation.

Study Design

Type: Interventional clinical trial (parallel groups).
Sample: 24 adults (87.5% women, mean age 52 ± 8 years) undergoing bariatric surgery.
Duration: 3-month postoperative period.
Methodology: Patients received protein supplementation with or without HMB (3 g/day). Outcomes included anthropometry, body composition (via dual-energy X-ray absorptiometry or similar), handgrip strength, and blood markers (inflammation, muscle damage, bone turnover). Adherence and physical activity were monitored.

Dosage & Administration

Dose: 3 g/day of HMB, divided into two doses.
Administration: Mixed into a protein supplement (exact formulation unspecified).
Comparator: Protein supplementation without HMB.

Results & Efficacy

Weight & Body Composition: Both groups lost significant weight (~18–19 kg) and fat mass, with no intergroup differences (p > 0.05). Lean mass decreased similarly in both groups.
Muscle Function: No differences in handgrip strength (p > 0.05).
Biomarkers:
Prealbumin: HMB group had higher levels (p = 0.04), indicating improved protein synthesis or absorption.
Inflammatory markers (CRP, IL-6), muscle damage (CK, irisin), and bone turnover (CTX, P1NP, sclerostin) showed no significant changes.
Physical Activity: Correlated with greater fat mass loss but not lean mass preservation.

Limitations

Small sample size (n=24) and short duration (3 months) may limit detection of long-term effects.
Sex bias: Overrepresentation of women (87.5%) reduces generalizability to men.
Self-reported activity: Potential inaccuracies in physical activity data.
Combined intervention: HMB was administered with protein, confounding effects of HMB alone.
Lack of mechanistic data: No insights into molecular pathways (e.g., muscle protein synthesis rates).

Clinical Relevance

For bariatric surgery patients, this study suggests that adding HMB to postoperative protein supplementation does not significantly enhance muscle mass or strength preservation compared to protein alone. However, the improvement in prealbumin—a marker of visceral protein status—warrants further investigation into HMB’s role in acute-phase nutritional support. Clinicians should prioritize adequate protein intake and structured exercise programs to optimize fat loss while minimizing muscle depletion. Larger trials with longer follow-up are needed to confirm these findings in diverse populations.

Source: PubMed | Date: 2025-06-19