Tackling Obesity from Every Angle: A Tailored Approach to GLP-1 Therapy, Advanced Endoscopy & Bariatric Surgery

In a country where obesity affects nearly half of all adults, discovering effective and sustainable solutions for weight management is no longer merely innovative — it's essential.

At Houston Methodist, Dr. Thomas R. McCarty is spearheading a pioneering, multidisciplinary approach to obesity, combining lifestyle interventions, pharmacotherapy, bariatric surgery and groundbreaking endoscopic procedures.

When Dr. McCarty joined Houston Methodist's Underwood Center for Digestive Health in 2022, the Gastroenterology Department's involvement in weight management was minimal.

"With the explosion of GLP-1 medication and other new treatment options in recent years, we recognized the need for a more comprehensive, integrated approach," said Dr. McCarty, a triple board-certified physician in internal medicine, obesity medicine and gastroenterology. "Traditional specialists, such as bariatric surgeons and primary care physicians, aren't always in the optimal position to coordinate individualized treatment plans, paving the way for gastroenterology to take a more central role in obesity management."

Today, the Houston Methodist program is among a select group of fully integrated multidisciplinary weight management centers nationwide. The collaborative team includes nutritionists, endocrinologists, psychologists, bariatric surgeons and gastroenterologists, collectively addressing the complex and multidimensional nature of obesity.

A transformative new class of medication

A cornerstone of the program is the innovative use of GLP-1 medications — such as tirzepatide and semaglutide — that have significantly changed the landscape of obesity treatment. Initiated several months before an endoscopic procedure, these medications enable combined weight-loss outcomes comparable to those achieved through traditional bariatric surgery.

"Typically, we begin GLP-1 medications about four months before endoscopic procedures, resulting in durable weight loss that often allows patients to stop medication upon reaching their goals," explained Dr. McCarty.

Patients at Houston Methodist undergoing combined GLP-1 and endoscopic sleeve gastroplasty (ESG) treatments have achieved remarkable outcomes, losing up to 29% of their total body weight. These results rival those of Roux-en-Y gastric bypass, traditionally viewed as the gold standard in obesity management.

Endoscopic sleeve gastroplasty is especially beneficial for patients who are not surgical candidates and those who prefer a less invasive initial option.

The minimally invasive procedure reshapes the stomach internally, reducing its size by approximately 80%, while preserving the organ's natural anatomy and function — avoiding common bariatric surgery complications like malabsorption and vitamin deficiencies.

"ESG is an outpatient, incisionless procedure that significantly reduces risk and recovery time," Dr. McCarty said. "Its minimally invasive nature makes it especially appealing for patients hesitant about more invasive surgical procedures."

Improving access to weight loss treatments

This integrated endoscopic and pharmacological approach is especially valuable given current treatment limitations.

Currently, only about 1% of patients eligible for traditional bariatric surgery actually undergo the procedure, often due to cost, side effects or reluctance to permanently alter anatomy. Additionally, drugs approved for weight loss are estimated to be covered by just 1% of marketplace prescription drug plans, making them financially inaccessible for many patients. Furthermore, research indicates that one year after withdrawal of weekly GLP-1 injections, participants typically regain two-thirds of their prior weight loss.

"Our combined approach offers a more accessible, sustainable solution to these challenges," Dr. McCarty said.

The Houston Methodist team has achieved notable successes, particularly with patients initially deemed ineligible for critical treatments due to high BMI, such as organ transplant candidates. Dr. McCarty cites a recent case where ESG and GLP-1 medications effectively reduced a patient's BMI, enabling her to qualify for a lifesaving transplant.

This integrative approach is also frequently used to safely prepare patients previously considered too high-risk for bariatric surgery.

"By helping patients achieve weight reduction preoperatively, we significantly decrease surgical risks and enhance postoperative outcomes," said Dr. McCarty.

The program's innovative ethos extends to clinical research, including a multicenter clinical trial exploring new duodenal procedures potentially capable of managing or even curing diabetes. Additionally, Dr. McCarty and colleagues have published a number of articles in recent years to highlight the evolving role of weight loss pharmacotherapy and the current landscape of endoscopic bariatric and metabolic therapies.

"Obesity is profoundly complex," said Dr. McCarty. "This integrated approach — combining lifestyle changes, cutting-edge pharmacotherapy, minimally invasive endoscopy and traditional surgical options — marks a turning point in obesity care and promises to improve patient outcomes nationwide."

To learn more about Houston Methodist's innovative new program, click here to read a full profile recently published in the Underwood Center newsletter.