Weight and Health: Picking the Right Target in Obesity Care

A concern is surfacing as obesity treatments become more and more effective. The measurement for success has long been percent weight loss. But thoughtful people have always known that the right target for obesity care was actually improved health. It was okay to focus on weight as a measure of effectiveness when the the effect of available treatments was modest. People reserved metabolic surgery for treating more severe obesity where too much weight loss was seldom a problem.

But with more potent drugs – like retatrutide – coming closer to market, people are starting to question some basic assumptions. John Batsis is expert in the care of older patients at the University of North Carolina. He explains that these questions are important and challenging:

“How much is too much weight loss is unknown, and we really need additional data and need studies to look at that. We need to be mindful of how much to push. Just because we can, doesn’t mean we should.”

Muscle Loss

Related to this concern, there is quite an ongoing buzz about muscle loss when using advanced obesity medicines. Writing in JAMA recently, Caterina Conte, Kevin Hall, and Samuel Klein explained:

People with obesity generally have greater amounts of fat free mass and skeletal muscle mass (SMM) than lean people, so the decrease in SMM induced by weight loss represents a small fraction of total body SMM. Moreover, even though the decrease in SMM can sometimes cause a decrease in muscle strength, it does not necessarily have an adverse effect on physical function.

Nonetheless, it bears watching, simply because it can affect physical function. Fatigue is an adverse event associated with both semaglutide and tirzepatide. Batsis told Stat News that, although most patients have good experiences with these advanced medicines, he has seen a handful of patients grow weak, even frail, after losing too much weight.

Health Outcomes

So it seems rather clear that some reorientation is necessary. Perhaps that should start with FDA, which presently labels these drugs as being for “reducing excess body weight.” We need to refocus on the treatment of obesity, which should emphasize health gain rather than weight loss.

Already we know these drugs are quite good at restoring metabolic health and reducing markers of cardiovascular health risk. Blood pressure, cholesterol, and blood sugar all get better with these medicines. On top of that, studies are showing that they prevent heart attacks, strokes, sleep apnea, osteoarthritis, and more. As even more data on diverse health outcomes emerges, the overemphasis on weight loss will become an ever more obvious mistake.

So by shifting the focus to health and physical function, we can steer people away from the rabbit hole of weight loss above all else. FDA can do its part by shifting its approach to the indications for obesity medicines.

Click here for more from Stat News, here and here for more on the effects of weight loss on skeletal muscle.

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February 25, 2025