Weight-loss procedure may be effective for form of rare obesity: Study
Benefits seen in patients with aHO were generally more limited, however
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A medical professional uses measuring tape to measure a person's waist.
A weight-loss procedure called bariatric surgery may be effective for adults with acquired hypothalamic obesity (aHO), but benefits generally appear to be more limited than those seen in people with common obesity, a study suggests.
While the surgery was generally safe and resulted in clinically meaningful weight loss, more than two-thirds of aHO patients did not achieve the level of response typically considered successful after surgery, data showed.
The findings suggest that weight-loss surgery may be considered for people with aHO, but “should be integrated into a comprehensive and long-term management plan,” researchers wrote.
The study, “Efficacy and Safety of Bariatric Surgery in Acquired Hypothalamic Obesity: A Systematic Review and Individual Patient Data Meta-Analysis,” was published in Obesity Reviews.
Bariatric surgery ‘the most effective weight loss intervention available’
aHO is a rare type of obesity caused by damage to the hypothalamus, a small brain region that helps regulate hunger and other bodily functions. This results in a wide range of symptoms, including excessive hunger and slower energy expenditure that results in rapid weight gain.
Treatment may include bariatric surgery, “the most effective weight loss intervention available,” the researchers wrote.
This includes procedures such as sleeve gastrectomy and gastric bypass. Sleeve gastrectomy involves removing a large portion of the stomach, limiting how much food it can hold, while gastric bypass creates a small stomach pouch that is connected directly to the intestine, allowing food to bypass most of the stomach.
Yet, the relative efficacy and safety of these procedures in people with aHO remains uncertain.
More than two-thirds of patients had suboptimal response
To learn more, a team of researchers in Denmark and France systematically analyzed studies published up to May 2026 that reported bariatric surgery outcomes over at least one year in adults with aHO.
A total of 13 studies, covering 36 aHO patients, were included in the final meta-analysis. Most studies were case reports and case series, and most were conducted in Europe.
Patients’ median age was 29 years, and their median body mass index (a ratio of weight and height used as a proxy of body fat) was 46.7 kg/square meter, which falls in the category of extreme obesity. More participants underwent gastric bypass (61.1%) than sleeve gastrectomy (38.9%).
A median of more than 2.5 years after surgery, participants lost a median of 16.5% of their body weight, equivalent to 25.6 kg (about 56.4 pounds). Even so, more than two-thirds (69.4%) had a suboptimal response, defined as losing less than 50% of their excess weight.
Those who underwent gastric bypass tended to lose more weight than those who had sleeve gastrectomy (17.4% vs. 15.2%), but this difference failed to reach statistical significance, meaning it could be due to chance.
The type and frequency of adverse events were generally similar to those expected after bariatric surgery.
Bariatric surgery in adults with acquired HO induces a clinically meaningful weight loss that is maintained at more than 2.5 years of follow-up, although the weight loss appears to be lower than in matched patients with [common obesity].
Because damage to the hypothalamus often also affects the nearby pituitary gland, people with aHO may develop hormone deficiencies requiring hormone replacement therapy (HRT). Treatments can include hydrocortisone, a replacement form of the cortisol hormone, and levothyroxine, a synthetic thyroid hormone.
In four studies with available HRT data, most patients did not require changes to their hydrocortisone treatment after surgery, while levothyroxine doses remained unchanged or required only minor adjustments. There were also no cases of adrenal crisis, a potentially life-threatening complication caused by too little cortisol.
Researchers also compared weight loss outcomes between 49 people with aHO and 223 with common obesity across four studies. Participants with aHO lost 12.5% less of their total body weight after bariatric surgery than those with common obesity. The risk of serious complications after surgery was similar between the two groups.
Weight loss after surgery may be more limited in people with aHO because damage to the hypothalamus could reduce the body’s response to the hormonal changes triggered by surgery, the team noted.
These findings indicate that “bariatric surgery in adults with acquired HO induces a clinically meaningful weight loss that is maintained at more than 2.5 years of follow-up, although the weight loss appears to be lower than in matched patients with [common obesity],” the researchers wrote.
However, because of the limited evidence available, they recommended that aHO patients be closely monitored after bariatric surgery. Also, “surgical intervention must be accompanied by continuous multidisciplinary care including nutritional support, behavioral and cognitive approaches, psychological and emotional follow-up, promotion of physical activity, and attention to sleep and [the body’s internal] rhythms,” the team concluded.
