Research

Hormonal

Bariatric surgery (RYGB and SG) induces sustained weight loss and metabolic improvements through hormonal and neural mechanisms (increased GLP-1/PYY, decreased ghrelin, altered bile acids) rather than solely through caloric restriction or malabsorption.

For patients with severe obesity, bariatric surgery (RYGB or SG) is the most effective treatment for sustained weight loss and metabolic health. The success is largely due to hormonal changes (increased GLP-1/PYY, decreased ghrelin) that reduce hunger and improve glucose control, rather than just eating less. This suggests that non-surgical treatments targeting these same hormones (like GLP-1 agonists) may be effective alternatives for some.

GoodSupportsHIGH confidence
It is now clear that a plethora of gastrointestinal (GI) tract-derived signals plays a critical role in energy and glucose regulation. SG and RYGB, which alter GI anatomy and nutrient flow, impact upon these GI signals ultimately leading to weight loss and metabolic improvements.
Andrea Pucci et al. · Journal of Endocrinological Investigation · 2018

Why this rating

Based on a review of multiple RCTs and observational studies (SOS, STAMPEDE, SM-BOSS), though individual variability exists.

Source

Mechanisms underlying the weight loss effects of RYGB and SG: similar, yet different

Andrea Pucci et al. · Journal of Endocrinological Investigation · 2018

DOI 10.1007/s40618-018-0892-2

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DOI resolved against Crossref · corpus check 2026-06-10

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