Medical Breakthroughs in Weight Loss

A drug to help shed pounds and build muscle?

Patients who shed pounds usually lose muscle mass along with fat. It’s a constant challenge for doctors who treat patients with obesity, says Fatima Cody Stanford, M.D., an obesity medicine physician at Massachusetts General Hospital in Boston and an associate professor of medicine at Harvard Medical School.

That’s why she and other experts have their eye on a new weight loss drug, bimagrumad, that appears to retain or even increase lean muscle mass.

A monoclonal antibody, bimagrumad works on a different target than other anti-obesity drugs. In early Phase 2 trial results published in  JAMA Network Open, patients lost almost 21 percent of their fat mass and gained nearly 4 percent in lean body mass. “It is the one agent I’m aware of in the pipeline that helps retain muscle mass,” Stanford says. “Retaining muscle mass is especially important for older adults, because losing muscle mass is already a part of the aging process. It affects frailty and mobility.”

Endoscopic procedures

For those who are reluctant to have bariatric surgery or don’t qualify for it, more doctors offer newer, minimally invasive endoscopic procedures for weight loss.

Instead of making incisions in your abdomen, a gastroenterologist accesses your digestive tract by inserting a thin, flexible tube through your mouth and down your esophagus.

“In a lot of people’s brains, there is some fear about bariatric surgery, so they may be more comfortable with a procedure where the doctor goes directly through the esophagus into the stomach,” Stanford says.

There are two main types of endoscopic weight loss procedures: In one, a doctor inserts a balloon made of silicone into your stomach to occupy space, so you feel full more quickly. In the other, which is more common, a doctor places stitches in your stomach to shrink it by about 70 percent.

A 2022 analysis of seven studies published in Obesity Surgery compared patients who had their stomachs stapled endoscopically to those who had their stomachs stapled during laparoscopic bariatric surgery. Both groups experienced weight loss, but the surgical patients lost more weight. The endoscopic patients experienced fewer side effects.

Beyond BMI: New ways to measure obesity

BMI has long been used to assess body weight and track obesity, but a growing number of experts question its accuracy as a health screening tool.

The measure, which is basically a ratio of height to weight, was invented back in the early 1800s by a Belgian statistician as a way to study populations of people. It was used by insurance companies to determine a person’s death risk. “It’s not derived from medicine or science,” Stanford says.

Kushner notes, “You can take the front linemen for your favorite football team and they all technically have obesity because they are heavier than they should be for their height.”

Conversely, some older adults have medical problems associated with excess body fat even though they don’t have a high BMI, he says.

Underwater weighing and DEXA scans (an imaging test that measures bone density) are more accurate ways to measure body composition, but they are expensive and impractical.

In recognition of the problem, a group of worldwide experts convened a Lancet commission to come up with a new way to define obesity. Stanford, who is on the commission, says she believes BMI will be a part of the equation, but it may include other indicators such as blood pressure, fasting glucose levels, waist circumference or waist-to-hip ratio.

A method called digital anthropometry also holds promise, Kushner says. It uses simple 3D optical imaging to scan your body and measure your fat percentage. A study published in January 2023 in the journal  Nutrients found that digital anthropometry is reliable and accurate, especially in patients with obesity.