People with the highest levels of obesity are undergoing fewer surgical procedures, despite growth in that patient population, a new analysis showed.

“We are seeing more patients with severe obesity who have been told they cannot undergo needed procedures — such as knee replacement, hernia repair, or hysterectomy — because of their weight,” Vance Albaugh, MD, PhD, of Pennington Biomedical Research Center and the Metamor Institute, Baton Rouge, Louisiana, told Medscape Medical News.

Albaugh often sees these patients for medical and surgical weight-loss treatment to help them become eligible for those operations, he said.

“It is not uncommon for patients to be told they need to lose 100 lb or more before a joint replacement surgery. For most people, that degree of weight loss is nearly impossible without access to effective medications, bariatric surgery, or both — yet those treatments are often not covered.”

The study was published online in Obesity.

Odds of Surgery Decline

Among the approximately 41% of the US population with obesity, prevalence of the highest BMI populations (eg, ≥ 60) is increasing most rapidly, Albaugh and colleagues wrote.

Given the association between obesity and surgical disease burden, the researchers hypothesized that people in higher BMI groups would account for a growing proportion of operative volume over time. But they were wrong.

Researchers analyzed 11.6 million multispecialty National Surgical Quality Improvement Program (NSQIP) cases from 2005 to 2022. The median age of included individuals was 58 years, 57.2% were women, and the median BMI was 28.9.

Most patients were White individuals (64.3%), followed by other/mixed (17.7%), Black (9.8%), and Hispanic (8.2%) individuals. Comorbidities included hypertension (44.39%), diabetes (15.36%), disseminated cancer (2.24%), and heart failure (1.24%). Most patients had an American Society of Anesthesiologists Class of 1 and 2 (53.14%), followed by Class 3 (40.58%) and Class 4 and 5 (6.12%).

Researchers analyzed trends by BMI category (< 30, 30-39.9, 40-49.9, 50-59.9, 60-69.9, and ≥ 70) and adjusted for demographics and comorbidities.

Overall, results showed that the higher the BMI category, the greater the decline in operative representation over time. Specifically, adjusted regression models showed decreased odds of patients with BMI 50-59.9 undergoing surgery over consecutive years (odds ratio [OR], 0.96; P < .0001), with increasingly higher BMI groups showing greater declines (OR, 0.94 for BMI 60-69.9 and OR, 0.87 for BMI ≥ 70; P < .0001 for both).

“We expected that patients with higher BMI might have more medical problems, which could partly explain lower surgery rates,” Albaugh said. “But even after accounting for other health conditions, the trend persisted. That suggests the issue is not simply medical risk — it may also reflect access barriers, institutional policies, insurance issues, or bias.”

In contrast, patients with a BMI 30-39.9 had an increased proportional operative volume.

The authors noted several study limitations. NSQIP represents clinical practice, is not randomized, and is prone to selection bias, they wrote. Because all cases in NSQIP represent patients who underwent surgery, nonoperatively managed patients or individuals who were not surgical candidates were excluded. The study’s retrospective design precludes determination of causality.

“There is a critical need to identify the mechanisms underlying these disparities to enable equitable healthcare access to higher BMI populations,” the authors concluded.

Underlying Causes

The reasons underlying the trends to less surgery for patients with obesity “are unclear and likely multifactorial,” the authors wrote.

One reason could be that obesity is associated with greater risks, which could affect elective surgical decision-making. Obesity is associated with longer operative times, increased risk for wound infection, and greater postoperative morbidity, they noted. In addition, individuals with obesity may have mobility issues and limited access to specialized equipment and infrastructure.

“All these factors affecting access to care would be expected to lead to delayed presentation and worse outcomes, especially with diseases (eg, cancer) in which late-stage presentation precludes curative surgical intervention,” they warned.

Insurers, hospitals, health systems, federal and state government, professional societies, and clinicians have a role to play in making surgery more accessible to people living with severe obesity, Albaugh said. Individual clinicians can help by “advocating for their patients, avoiding using BMI alone as a reason to deny care, and helping patients understand that obesity is a complex chronic disease — not a personal failure,” he added.

A Call for Change

The study findings are concerning, Melanie Jay, MD, professor of medicine and population health director, NYU Langone Comprehensive Program on Obesity Research at the NYU Grossman School of Medicine, New York City, told Medscape Medical News.

“Over time, we would hope that surgeons would feel more comfortable doing surgeries on patients with obesity and that the equipment and systems would evolve to accommodate larger bodies,” Jay said. There are systemic incentives to avoid surgical patients at higher risk for complications, adverse outcomes, and longer lengths of stay to improve quality and safety metrics, and that may create a selection bias against people with severe obesity, she said.

“Quality metrics should be amended to account for the increased risk of doing certain procedures in patients with obesity,” she added.

Jay said that in an effort to reduce surgical risks, orthopedic surgeons often require patients with severe obesity to get their BMI < 40 before doing hip or knee replacement surgery. “However, there is little data about whether weight loss before orthopedic surgery actually improves outcomes in patients with class 3 obesity or just delays care, thus worsening outcomes for the individual,” she said.

“We have seen in some of our ongoing analyses that patients with class 3 obesity and prostate cancer are also less likely to get surgery and more likely to get hormonal treatments,” she noted. “We were told by surgeons that this is due to the perceived higher risk of the surgery.”

Patient reluctance to visit the doctor is a key factor that may have influenced the findings, Jay said. “Patients experience stigma in the healthcare system and may not seek out care. They also may have poorer mobility, so they don’t get screened for cancer as often or receive care to detect other conditions amenable to surgery. CT scanners and MRIs often do not accommodate severe obesity — again, leading to delayed diagnosis.”

The medical community has the same level of anti-fat bias as the rest of the country and should take steps to address it, Jay said. “We need more outreach to patients and friendlier environments within our clinics, including larger chairs and exam tables,” she added.

Albaugh reported receiving funding from the National Institutes of Health. Jay declared consulting in 2025 for AbbVie and Novo Nordisk and serving on the advisory boards of Onsera Health and Bonus Health.

Marilynn Larkin, MA, is an award-winning medical writer and editor whose work has appeared in numerous publications, including Medscape Medical News and its sister publication MDedge, The Lancet (where she was a contributing editor), and Reuters Health.