Obesity treatment persistence: why it matters

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Obesity treatment persistence: why success is measured over time

By Dr. Asnat Raziel, bariatric surgeon specializing in obesity treatment, metabolic health and healthy longevity; Director of the Multidisciplinary Center for Obesity Treatment, Assia Medical, Assuta Ramat HaChayal, Tel Aviv

Obesity treatment persistence: the key most patients miss

Persistence with obesity treatment is one of the most important factors in the success of drug therapy for obesity. Studies show that the medications work well, but only for as long as you take them. Real-world data, however, reveal that about half of patients stop treatment within a year. In this article, we will look at what happens when people stop, why they stop, and how to stay on track.

Obesity is a chronic disease

To understand why persistence matters, we need to start with the definition. The World Health Organization and the European Association for the Study of Obesity now define obesity as a chronic, relapsing disease. The Lancet Commission has also defined clinical obesity as a chronic disease. In other words, it is not a condition you fix once and then forget about.

When weight drops, the body fights back, as a study published in NEJM showed. Hunger hormones rise, satiety hormones fall, and appetite grows stronger. These changes persist even a year after the weight loss. So, as with high blood pressure or diabetes, obesity also requires ongoing treatment. I discuss this in more detail in my article on obesity as a chronic disease.

What professional organizations say

In December 2025, the World Health Organization published its first global guideline on the use of GLP-1 medicines to treat obesity. The WHO recommends liraglutide, semaglutide and tirzepatide for long-term treatment in adults, and it also recommends combining them with a behavioral program. These are conditional recommendations, partly because long-term data and data on stopping treatment are limited, and partly because of cost and access. Still, the WHO’s message is clear: obesity requires comprehensive, ongoing, lifelong care.

What happens when you continue treatment

Researchers tested Wegovy, whose active ingredient is semaglutide, in the STEP series of trials. In the STEP 5 trial, patients in the semaglutide group lost an average of 15.2% of their body weight after two years, compared with 2.6% on placebo. Moreover, 77.1% of them lost at least 5% of their weight.

The SELECT trial, which examined the drug’s effect on the heart in people with heart disease and without diabetes, provides especially long-term data. An analysis of weight in the trial showed a 10.2% reduction after four years, compared with 1.5% on placebo. In addition, waist circumference shrank by 7.7 cm. Weight loss continued for about 15 months, and after that, weight remained stable for years.

What happens when you stop: evidence from the trials

The STEP 1 trial extension gives a clear answer. Participants lost 17.3% of their body weight over 68 weeks. They then stopped both the drug and the lifestyle program. A year later, they had regained about two-thirds of the weight they had lost. In addition, the improvements in blood pressure, blood sugar and blood lipids largely returned to baseline.

Even so, the gains did not vanish completely. After two years, weight was still 5.6% below baseline. In other words, stopping treatment does not undo everything, but it gives up most of the benefit.

The controlled withdrawal trial: STEP 4

In the STEP 4 trial, all participants received semaglutide for 20 weeks and lost an average of 10.6% of their weight. The researchers then randomly assigned them to two groups. Those who continued treatment lost a further 7.9%. By contrast, those who switched to placebo regained 6.9%. The difference between the groups was 14.8 percentage points.

More recently, a meta-analysis in the BMJ pooled 37 studies. Averaged across all drugs, the researchers found weight regain of about 0.4 kg a month after stopping. With the newer drugs, semaglutide and tirzepatide, the pace was even faster: about 0.8 kg a month, with an estimated return to baseline within about a year and a half. Heart and blood sugar markers also return to baseline, and even faster. However, these estimates rely on follow-up of up to one year after stopping.

Obesity treatment persistence in the real world

Clinical trials offer close follow-up, support and free medication. Real life, on the other hand, looks different. Real-world evidence, meaning data from routine care outside of trials, shows a large gap.

For example, a US study of about 125,000 adults found that 64.8% of patients without diabetes stopped GLP-1 treatment within a year. In Denmark, preliminary data on about 77,000 Wegovy users showed that 52% stopped within a year. In addition, an analysis by a US pharmacy benefit management company, presented at a conference, found that only 24.1% of Wegovy users were still on treatment after two years.

Persistence with obesity treatment shapes the outcome

A Cleveland Clinic study of 7,881 patients showed the price of stopping early. Those who stopped within the first three months lost an average of 3.6% of their body weight over a year. By comparison, those who continued treatment lost 11.9%. What is more, among patients with prediabetes, blood sugar returned to the normal range in 67.9% of those who continued, compared with 33% of those who stopped early.

Early success encourages persistence

There is also an encouraging side. In the large US study, each percentage point of weight loss lowered the risk of stopping treatment by about 3.3%. In other words, people who see early results tend to keep going. That is why it is important to track progress regularly, and not only by weight. Waist circumference, blood tests and how you feel overall are also measures of success.

Why do patients stop?

Another Cleveland Clinic study looked at the actual reasons. The most common reason was cost or insurance, cited by 47.6% of those who stopped. Next came side effects, at 14.6%, and drug shortages, at 11.8%. Only 1.7% stopped because they did not lose enough weight.

The pattern is revealing. Side effects mainly led to early discontinuation, in the first months. Cost problems were the leading reason at every stage, but they stood out especially in later discontinuation. Of course, these data come from the US, and Israel’s coverage system is different. Even so, the lesson is clear: you can identify and plan for most of these factors in advance.

How to strengthen obesity treatment persistence

Here are some practical principles, based on research and clinical experience:

Gradual dose escalation: most digestive side effects appear while the dose is going up, and they ease over time. So there is no need to rush; instead, adjust the pace to the individual.

Managing side effects: small meals, eating slowly, drinking enough fluids and avoiding fatty foods make a big difference. I cover this in detail in my article on GLP-1 side effects.

Setting expectations early: the Danish researchers pointed to a gap in patient education about how long treatment lasts. A conversation about this at the start changes the picture.

Close follow-up with a multidisciplinary team: a doctor, a dietitian and a psychologist can help spot difficulties early, before they lead to stopping.

Protein and strength training: preserving muscle mass supports long-term weight maintenance.

What if you still need to stop?

Sometimes there is a good reason to stop, such as a planned pregnancy or a significant side effect. In such cases, stop with a plan and with support, not all at once and without preparation. I wrote a detailed guide on this topic: how to prepare properly for stopping treatment. In addition, the REST trial is now testing whether gradual tapering reduces weight regain.

After stopping, it is also important to reinforce the habits you built during treatment. A diet rich in protein and fiber, regular exercise and enough sleep help your body cope as appetite returns. I explore this further in my article on maintaining weight after weight loss. The emotional side matters too: fear of regaining weight is a common feeling, and you can learn to cope with it. In most cases, support from a dietitian and a psychologist during this period changes the outcome.

Questions and answers on obesity treatment persistence

Will I need to take the medication for life?

Not necessarily, but it is important to treat obesity as a chronic disease. In the trials, most of the weight came back within a year of stopping. Therefore, you and your doctor decide together how long to continue, based on your health, goals and resources.

Can I continue on a lower dose?

In the real world, about 81% of patients in the Cleveland Clinic study received a low maintenance dose of less than 1.7 mg of semaglutide. However, those who continued semaglutide at a high dose lost an average of 13.7% over a year, compared with 10.9% across all those who continued semaglutide. There are no controlled trials yet on reduced-dose maintenance, so the decision is a personal one.

What should I do if the side effects are hard for me?

Don’t stop on your own. First, contact your care team. Usually, your doctor can slow the dose escalation, adjust your eating habits or treat the symptoms. In most cases, side effects ease within a few weeks.

The bottom line: persistence is part of the treatment

Obesity medications, led by Wegovy, achieve significant and lasting weight loss for as long as you keep taking them. On the other hand, stopping early brings back much of the weight and the risk. Obesity treatment persistence is therefore not a matter of willpower but part of a professional treatment plan. Planning ahead, close support and managing side effects greatly increase your chances of long-term success.

This article provides general information and does not replace personal medical advice.