Doctors and researchers are cautioning that many people using injectable weight-loss medications could need to remain on them indefinitely, after evidence showed the pounds often come back swiftly once treatment ends.
In a large new review led by Oxford researchers, weight regain was found to be common and rapid after people stopped using the drugs, even among those who had lost substantial amounts. The analysis drew on 37 studies covering more than 9,300 participants and compared outcomes across all licensed weight-loss medications and behavioural programmes.
On average, people who discontinued the injections put weight back on at a rate of about a pound a month. Based on the data, many were expected to regain most or all of the lost weight within roughly 17 to 20 months, regardless of how much they had initially shed.
Professor Susan Jebb, who co-authored the review and advises ministers and the NHS on obesity, said the findings suggest a need to rethink how these drugs are viewed and prescribed. She said: “Obesity is a chronic relapsing condition, and I think one would expect that these treatments need to be continued for life, just in the same way as blood pressure medication.”
“We should see this as a chronic treatment for a chronic condition,” she added.
The injections — including widely used brands such as Mounjaro and Wegovy — belong to a class of medicines known as GLP-1 drugs. They mimic hormones released after eating, helping to suppress appetite and regulate blood sugar. Their arrival has been widely seen as a turning point in obesity care, offering levels of weight loss rarely achieved through diet and exercise alone.
However, the Oxford team warned in The British Medical Journal that the benefits can be short-lived once the drugs are withdrawn. Not only did weight return quickly, but key cardiometabolic improvements also faded. Gains in blood sugar control, blood pressure and cholesterol typically disappeared within 18 months of stopping treatment.
Weight regain occurred around four times faster than among people who lost weight through diet and exercise alone. While those on lifestyle programmes generally lost less — about 5kg over a year — they tended to regain weight far more slowly, at around a fifth of a pound a month. In that group, heart-health benefits often persisted for up to five years after the programme ended.
Dr Adam Collins, an associate professor of nutrition who was not involved in the research, said the mechanism behind the drugs helps explain the rebound effect. “As soon as the drug is stopped, appetite is no longer kept in check,” he said.
“If people haven’t built sustainable habits alongside treatment, going cold turkey can be extremely difficult – and some may regain even more weight than they lost.”
The review found that people using injections typically lost close to two-and-a-half stone (14.7kg) within nine to 12 months. But once treatment ended, most were projected to return to their starting weight within two years.
The findings are likely to intensify debate over NHS policy. Under current rules, Wegovy is offered for a limited period of up to two years. Most users, however, obtain the drugs privately, often paying as much as £300 a month — raising concerns about affordability if long-term or lifelong use is required.
Professor Jebb said real-world use also presents challenges. “What we’ve shown is that weight regain after treatment is common and rapid – suggesting the jabs should not be seen as a short-term solution,” she said.
“In the real world we know that adherence is surprisingly poor, with around half of people discontinuing these medications within a year.”
An estimated 2.5 million people in the UK are currently using newer GLP-1 weight-loss drugs. At the same time, around two in three adults are classed as overweight or obese. NHS data show adults now weigh roughly a stone more than they did three decades ago, a trend estimated to cost the economy £100 billion annually.
Eligibility for NHS-funded treatment is already restricted. Only patients with a BMI over 35 and a weight-related health condition, or those with a BMI between 30 and 34.9 referred to specialist services, qualify. More than half of local health commissioners in England are expected to further tighten access due to cost pressures.
Obesity is linked to at least 13 types of cancer and is the second biggest cause of the disease in the UK, according to Cancer Research UK. It has also driven a 39 per cent increase in type 2 diabetes among under-40s, with about 168,000 young people now living with the condition.
While concerns have been raised about side effects — including nausea, vomiting and diarrhoea, and rare cases of pancreatitis — many specialists say the overall benefits outweigh the risks for most patients.
Professor John Wilding, an honorary consultant physician in cardiovascular and metabolic medicine at the University of Liverpool, said the results were to be expected. “We don’t expect treatments for diabetes, high blood pressure or high cholesterol to continue working once medication is withdrawn – and there’s no scientific reason obesity should be different,” he said.
“These drugs should be considered long-term treatments, not a quick fix.”
{Matzav.com}
