Study details

For the study, which was sponsored by Eli Lilly, 670 people with a body mass index (BMI) of 30 or higher or a BMI of at least 27 with one weight-related health complication aside from diabetes took tirzepatide for nine months. Then, the participants were randomly and blindly assigned to either continue taking the drug or begin taking a placebo for a year.

Tirzepatide is sold by Eli Lilly under the brand name Zepbound for weight loss and has been available as Mounjaro for type 2 diabetes.

The researchers found that, after nine months, patients lost an average of 20.9% of their body weight. The patients who continued taking the medication for another year lost an additional 5% of their original body weight, while those taking the placebo gained 14% of their body weight back and saw improvements in blood pressure, cholesterol levels, and waist circumference start to wane.

However, the researchers found that even after a year of taking a placebo, patients didn't return to their original weight and still saw improvements in some areas, like being more sensitive to insulin, reducing their diabetes risk, and having healthier levels of triglycerides.

Discussion

Louis Aronne, an obesity expert at Weill Cornell Medicine and lead author on the study, said he was "surprised how good the result was" in the study.

"Just like diabetes, hypertension, hyperlipidemia, and many other metabolic diseases, the results show that chronic treatment of some type is going to be necessary in order to maintain all the benefits of weight loss achieved with the treatment," he said.

Aronne added that the finding that patients who took the placebo still saw some improvements and didn't return to their original weight "tells us that chronic treatment is going to be necessary for optimal outcomes but that all of the benefit is not lost immediately if people stop taking that treatment."

However, since tirzepatide was only approved in November, it's too early to know how long people may need to take the medication or how it best fits within a weight-loss program, Aronne said.

"What if some people go to a lower dose of the medicine, or take it less frequently, or have more intensive behavioral or nutritional interventions? Will they be better able to maintain their weight loss?" he said. "All of those things are possible; we'll just have to wait and see."

Advisory Board's weight-related resources

According to CDC data, more than 70% of U.S. adults ages 20 and older are either overweight or obese. Obesity is also prevalent  among children, with rates growing between 17.7% and 21.5% over the last decade.

As obesity rates continue to rise, so will healthcare costs. Currently, obesity costs the U.S. healthcare system $173 billion every year.  

To help address the growing weight-related issues in healthcare, Advisory Board offers several resources on different topics, including:

­GLP-1 drugs

Interest in new weight-loss drugs, including Novo Nordisk's Wegovy and Eli Lilly's recently approved Zepbound, has surged this year, leading to record sales — as well as supply shortages as manufacturers struggle to keep up with demand.

Advisory Board's Chloe Bakst and Rachael Peroutky  recently shared their insights on how GLP-1 shortages might impact healthcare and what leaders can do in the meantime.

Radio Advisory's Rachel Woods has also covered GLP-1 drugs on the podcast, discussing the  potential future of these drugs  and how they could help — or hurt —  health systems' finances.

Other useful resources include the expert insights  "5 catalysts that will impact the future of weight management drugs,"  and  "What the headlines get wrong about weight management medications."

Bariatric surgery

Last year, the  American Society for Metabolic and Bariatric Surgery and the International Federation for the Surgery of Obesity and Metabolic Disorders updated guidelines for weight-loss surgery, expanding eligibility for more people.

Under the new guidelines, anyone with a BMI over 35, regardless of whether they have any health problems, is eligible for weight loss surgery. People with a BMI over 30, which is the official definition of obesity, are also eligible if they have not been able to achieve substantial or long-term weight loss.

This expert insight outlines three barriers to bariatric surgery and how to overcome them. For patients considering bariatric surgery, this resource offers three factors they should keep in mind  while they decide.

Healthcare's approach to obesity

Recently, healthcare organizations have made an effort  to move away from using BMI to determine obesity and assess health. In June, the American Medical Association voted to adopt a new policy that moves away from using BMI alone when assessing whether a patient is at a healthy weight.

Some physicians are also looking beyond BMI and people's weight as they assess their health and recommend treatments. Rather than focusing on weight loss as a way to treat health issues, some providers are now taking a "weight-neutral" approach that avoids intentional weight loss.

In a recent Radio Advisory episode, Rachel Woods and Advisory Board experts Darby Sullivan and Chloe Bakst discussed healthcare's current approach to obesity and whether it is helping or harming patients.

Similarly, this expert insight covers three missteps in our current approach to obesity and outlines five potential ways providers can address these issues. (Roy, Reuters, 12/11; Park, TIME, 12/11; Langreth, Bloomberg, 12/11)