THE INTERVIEW: Life after weight-loss medication — what happens when the injections stop?

There is something deeply unsettling about the research on what happens when people stop taking weight-loss medications.

In Life After Weight-Loss Medication, Dr Linia Patel notes that in the landmark Semaglutide Treatment Effect in People with Obesity (STEP) 1 trial, participants taking semaglutide lost an average of 17.3% of their body weight over 68 weeks. Within a year of stopping the medication they had regained about two-thirds of the weight they had lost.

This is not the only cause for concern. 

The STEP 1 trial also used a subset of 140 participants who had DEXA scans to measure their body composition. The average weight loss in this subset was 13.6kg, of which an estimated 5.3kg (39%) came from lean mass.

Put plainly, that is roughly four of every 10kg lost coming out of muscle and organ tissue, and lean mass is the part of the body that does the daily work of keeping a person upright, mobile and metabolically solvent. 

Patel’s book is clear about what its loss costs. Less muscle means reduced mobility, a slower metabolism and a greater chance of regaining weight, and it speeds up the ageing of the body. Over time, the decline can end in sarcopenia, a condition marked by the progressive loss of strength, function and independence. 

The cruelty of the sequence is that the weight that comes back after the medication stops is mostly fat, so the body that emerges from the cycle has less muscle and more fat than the one that went in, and possibly a slower metabolism with which to deal with the difference.

This matters at any age and matters most for older people, who start the process with less muscle in reserve and have a harder time rebuilding it. A drop in lean mass that a 30-year-old might shrug off can take an older person closer to the threshold where everyday tasks become effortful, and the kilograms on the scale give no hint of it. 

Patel told me that older women can still use these drugs as a tool, provided they are even more proactive about protecting their muscle than anyone else on the medication, and that means not letting the drug silence their appetite so completely that they stop eating enough. For someone in her seventies, the question that matters is less how many kilograms she has lost than whether she can still rise from a chair.

I found myself wondering what the point of taking these medications was if the weight was likely to return, potentially leaving people metabolically worse off. It was one of the first questions I put to Patel when we met to discuss her book. 

Patel, a registered dietitian with more than 20 years of experience in weight management, including bariatric services and public health programmes, is unequivocal about the benefits of these drugs. She describes them as transformative, capable of producing weight loss approaching that achieved through bariatric surgery, without the surgery itself. They also offer important metabolic health benefits. 

But she is equally concerned about how people are using them, particularly without adequate medical, nutritional and psychological support. Her concern is that we have become so preoccupied with losing weight that we have neglected the considerably harder question of maintaining that loss.

Patel told me the book grew out of a gap she kept meeting in practice. People would say they were taking the medication to lose weight, and when she asked about their long-term plan, many had not thought about one.

In Britain, where the National Health Service cannot supply most of those who want these drugs, she estimates that about 90% of users pay privately, and she links that cost to the roughly 60% who stop within six months to a year. 

She explains how the drugs work: they slow gastric emptying, so food stays in the stomach for longer, and they quieten the persistent thoughts about food that many users call food noise. Some people lose their desire for ultra-processed foods, and others simply forget to eat.

One of her patients described feeling permanently as though she had just finished Christmas dinner. That sounds appealing to anyone who has struggled with weight, but Patel’s argument is that eating much less carries costs of its own. 

My favourite line in the book states it simply: eating less isn’t just fewer calories, it’s fewer of everything. Less protein, less fibre and far fewer of the vitamins and minerals the body needs every day. Nausea and constipation are the side-effects she sees most often in her practice, together with fatigue and hair loss.

Stopping brings a different difficulty, because once the medication is gone the biological brakes are released and regain can be sharp and fast. The book responds by concentrating on what a person can control: keeping muscle, prioritising protein, strength training, managing stress and rebuilding an internal sense of appetite. 

Stress has a part in this, since both acute and chronic stress have been shown to lower naturally occurring GLP-1 levels in the brain, and some scientists suspect that long-term high doses may temporarily reduce the body’s own GLP-1 production.

Her practical advice is to work with a prescribing clinician to find the lowest effective dose, so that you are hungry enough to eat properly and are losing fat rather than muscle.

Patel organises her approach around four pillars, which she calls NEAI: Nourish, Energise, Align and Integrate. 

Nourish addresses eating to support satiety, gut health and muscle maintenance. Energise focuses on strength, consistent movement, sleep and recovery. Align explores the psychological dimensions of weight management, including emotional eating, cravings and rebuilding trust in hunger signals. Integrate brings these elements together into a sustainable, individualised plan. 

We have long known that nutrition, movement, sleep and psychological wellbeing are connected, and the book’s use lies in applying that knowledge to people whose relationship with food has been changed by a drug.

Patel asks readers to look beyond the scale, using a bio-psycho-social framework, which means eating in a way that supports your muscles, brain, bones and gut, moving regularly, sleeping well and attending to stress. 

There is a chapter on movement, rest and resilience and another on the mental side of weight management, along with questions to consider, practical exercises and recipes for breakfast, lunch and dinner, including sweet treats such as anti-inflammatory chocolate and coconut bars.

I put to her the view of a psychiatrist who believes these drugs are sometimes prescribed irresponsibly, with too little attention to the psychological factors behind obesity. Patel agreed that psychological support should be central to any weight management pathway. 

“Obesity is the largest public health epidemic of our time, one that public health has so far failed to curb,” she told me. In her view the new drugs have changed the landscape, and the operative word is context: who is taking them, and with what support.

Her concern goes beyond the individual patient. For years, public health practitioners have argued that obesity is not a failure of willpower and have pointed to an obesogenic environment, in which unhealthy food is everywhere, heavily marketed and often easier to reach than healthy alternatives. 

“We live in a culture that is obsessed with us being thin,” she said, “but makes it so hard.” A pharmaceutical answer risks handing responsibility back to the individual, since the question becomes why you are still overweight when medication exists, and it lets governments and policymakers off the hook. 

It also deepens inequality. People with money can take the drugs, sometimes needing to lose only 5kg to 10kg, while those with greater health needs, who do not have the resources, cannot reach them.

The book’s usefulness extends beyond people on these drugs. I found that most true of her advice on sleep. I told her that I am fighting the fact that my bedtime had crept towards one in the morning because I’m addicted to books, and she replied that consistency matters more than almost anything else.

Going to bed before midnight helps, and that a good night begins in the morning, when natural light reaching your eyes in the first hour after waking helps to reset the body’s circadian rhythm. 

It was the simplest advice I was given, and the only part that needed no prescription: open the blinds. DM

Joy Watson is Daily Maverick’s book editor-at-large.

Life After Weight Loss Medication is published by Murdoch Books. It is available at a retail price of about R515.