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By Matthew Rees

Food and Health Fact #197:

Focus on obesity prevention -- not panaceas

This January marks the 60th anniversary of the landmark Surgeon General’s report on the nexus between smoking and health. At the time, 42 percent of American adults were smokers, and lung cancer had become the leading cause of cancer in the United States. The report helped ignite a prolonged, and multi-pronged, effort to curtail tobacco use.

It worked. Today, the adult smoking rate is down to 11.5 percent. Coupled with the treatment of HIV-AIDS, the decline in smoking counts as the country’s greatest public health victory in the past half century.

I thought of the Surgeon General’s report amid the widespread popularity of weight-loss drugs like Wegovy, Ozempic, and Mounjaro (the latter two are actually treatments for type 2 diabetes, but weight loss is a byproduct). They’re being hailed as miracle therapies that, in the breathless words of an overzealous headline writer at The Economist, promise “huge savings for health systems and better lives for millions,” with the potential to “end obesity.”

While it’s folly to think the drugs are going to end obesity – even their manufacturers don’t make such a claim – they do offer non-trivial benefits around suppressing appetites and, by extension, driving weight loss.

But as I’ve written previously, it’s far too early for Economist-style exuberance about these drugs. And amid all hype around them, there’s one macro question that’s largely being glossed over: whatever happened to obesity prevention?

First some background about the drugs. Available by prescription, they typically involve weekly injections, which are self-administered. A long article in the New Yorker included a useful description of how they work:

The drugs mimic a hormone called glucagon-like peptide-1, which stimulates insulin production and suppresses the production of glucagon, which raises blood sugar. The body naturally releases GLP-1 after a meal, and the hormone travels to the brain, triggering the feeling of fullness. GLP-1 drugs effectively inject that sense of satiety, and also slow the rate at which food empties out of the stomach; patients generally report a freedom from cravings and an inability to overeat without becoming ill.  

One study showed that people using the drugs for more than a year lose, on average, nearly 15 percent of their body weight. And they’re like statins and other popular treatments: they must be taken in perpetuity. So can people stay on these drugs?

A recent analysis by Reuters suggests not. More than 4,000 patients taking Wegovy, Ozempic and other drugs were followed and only 32 percent of them had stayed on the therapies for one year. The high cost of these drugs – typically more than $1,000 per month – wasn’t the reason, as insurance covered the drug for all the patients taking it.

A Vanderbilt health policy researcher quoted in the Reuters article highlighted a critical issue: “There can be a lot of spending on people that are not likely to reap any long-term health benefits.”

The side effects were surely part of the problem. Nausea affects 44 percent of those who take Wegovy, while the incidence of diarrhea is 30 percent, vomiting 24 percent, and constipation 20 percent. And recent anecdotal evidence, reported by CNN, points to another unpleasant side effect: severe gastroparesis, which is better known as “stomach paralysis.”

Very high levels of health care spending, combined with very poor health outcomes, is a hallmark of the U.S. health care system. And the proliferation of weight-loss drugs is unlikely to change this sad state of affairs, given that they don’t do anything to prevent obesity, nor advance our understanding of its underlying causes.

(These drugs are also very expensive; having them covered by Medicare – the subject of aggressive lobbying campaign – would sharply increase spending on health care. “Obesity is the new hypertension and looks set to become the next blockbuster pharma category,” wrote Morgan Stanley in a report last year.)

David Ludwig, an obesity researcher, and professor at Harvard Medical School, emphasized the prevention/knowledge point in a recent Harvard Gazette article:

Big pharma can come up with a billion dollars to take a promising drug through Phase 3 clinical trials without difficulty because the profits can be enormous, whereas researchers trying to understand the environmental and dietary drivers of obesity must manage with a shoestring budget.

It’s not surprising we’re left with weak interventions. Most dietary clinical trials are small, low-intensity, and low-quality — a hundred of these can’t produce the knowledge of one good study. . . .  

With availability of new powerful drugs and surgical procedures, the incentives are to promote them. They’re huge moneymakers for drug companies, surgeons, and hospitals. We tend to lose sight of lifestyle and dietary interventions because few influential organizations profit in the same way.  

Beyond generic interventions like making physical activity more convenient, we must take a more sophisticated approach to investigating the biological effects of diet. The type of foods we eat alter dozens of hormones, hundreds of metabolic pathways, and the expression of myriad genes throughout the body in varying ways. Knowledge of these effects, combined with intensive behavioral methods, could inform the design of effective alternatives to drugs and surgery for prevention and treatment. 

There’s another way in which the weight loss drugs have highlighted the knowledge deficit around obesity: the drugs were designed to help treat diabetes. Weight loss was an unintended outcome. “That right there should be a clear sign of how little we understand about obesity,” Dariush Mozaffarian, MD, a nutrition professor at Tufts School of Medicine, told WebMD.

Ludwig hints at a fundamental issue with the weight loss drugs: they treat obesity, but they don’t do anything to prevent it. And while the U.S. health-care system is designed to treat people – it’s more “sick care” than “health care” – the real goal should be something that’s largely overlooked – and sometimes dismissed as heresy: keeping people healthy so they don’t need a litany of pills, procedures, injections, and other interventions.

The real worry is that these weight loss drugs will function as the dietary equivalent of a get out of jail free card – with users maintaining a diet that’s calorically dense, and nutrient poor, and heavy on ultra-processed concoctions, but just consuming less. That may lead to weight loss, but it’s still going to leave them in poor metabolic health.

(Another reason for tempered enthusiasm: the weight loss that does occur can also lead to the loss of muscle mass that is fundamental to health, particularly in people over 65.)

The optimal approach to driving weight loss, and curtailing obesity, is interventions that advance an age-old objective: getting people to eat healthier, which means consuming more vegetables, fruits, whole grains, and legumes in their natural state (i.e. not processed). These foods deliver a range of health benefits, while simultaneously crowding out the CRAP (calorie rich and processed) foods. Think “farmacy,” not “pharmacy.”

Returning to the tobacco example, pharmaceuticals played a small role in driving down the smoking rate over the past 60 years. The real drivers were taxes, advertising bans, mass media campaign, smoke-free policies, and graphic pack warnings, point out the authors of a paper published by the American Association for Cancer Research.

And pharmaceuticals? “Despite promises of the efficacy of different stop smoking treatments,” write the authors, “there is not much evidence that any of these therapies have dramatically reduced rates of tobacco use.”

Maybe future weight loss drugs will overcome the limitations of today’s options. But I doubt it. And the smoking example is a potent reminder that behaviors can change and that there’s a way out of the obesity calamity that doesn’t involve medicating millions of Americans indefinitely.