How to prevent the weight from coming back after Mounjaro: New research shows simple steps can cut regain by two-thirds, with experts setting out eight rules to follow when you stop the injections

For millions who have shed weight on Mounjaro or Wegovy, one question looms large: will the pounds return once treatment ends?

Encouraging new research suggests there may be a way to sharply reduce that rebound, and the answer could be as straightforward as putting the right support in place after the injections stop.

In the first clinical trial of its kind, scientists tracked 39 people who had lost at least 10 per cent of their body weight with GLP-1 drugs and had stopped taking them within the previous month.

Participants were split into three groups. One received standard medical advice, a second used the weight-management app Noom, which prompts users to record food and weight while teaching ways to handle cravings and change eating habits, and the third had ten dietitian-designed, calorie-controlled meals delivered to their homes each week.

The results after four months were striking.

Those given usual care regained an estimated 10.75 per cent of their body weight.

For a person around the average weight in the study, roughly 13st 7lb, that would amount to about 20lb, or nearly a stone and a half.

By comparison, the app group regained just 3.6 per cent, while the meal-delivery group regained 3.58 per cent — the equivalent of only about 7lb for someone of the same weight.

In other words, both structured-support groups regained around a third as much weight as those left to manage without extra help.

The US team says this is the first randomised trial to test either a digital behavioural programme or medically tailored meals specifically as a way of maintaining weight after stopping GLP-1 drugs.

The findings matter because coming off the injections can be difficult. Earlier research suggests weight regain is especially rapid in the first three to four months after stopping, and that many patients regain at least half of what they lost within a year.

There is, however, an important caveat. The study was small, involving just 39 people, and it lasted only four months.

The researchers themselves say far larger and longer trials are needed to show whether the apparent benefits last.

Even so, the findings add to growing evidence that regaining weight after Mounjaro or Wegovy is not inevitable — and that a clear plan for life after the injections may make a major difference.

So what should that plan include?

We asked leading obesity and nutrition experts for the eight rules that could give you the best chance of keeping the weight off long term.

DON'T STOP SUDDENLY

Evidence suggests tapering the dose gradually, rather than quitting all at once, may help keep the weight off more effectively.

One study by weight-loss clinic Embla, presented to the European Congress on Obesity, found that patients who reduced their dose over nine weeks not only continued losing weight during that period, but also kept their body weight stable for the next six months of the study.

Lead researcher Dr Henrik Gudbergsen said patients should also make diet and lifestyle changes.

Professor David Strain, an expert in metabolic disease at the University of Exeter, agrees that this approach can help some patients.

“First, patients should move to a lower dose and then begin increasing the time between doses before stopping completely,” he says. “While I've seen patients gain weight again, it hasn't been large amounts.”

Zoe Griffiths, vice-president of behavioural medicine at digital healthcare provider Numan, says this means appetite tends to rise more slowly.

“That may make it easier for patients to adjust,” she says.

EXERCISE MATTERS

Only one high-quality study has looked at the best way to maintain weight loss after stopping the injections, and it found that regular exercise makes a major difference.

Experts say people should start exercising while still on the medication and keep it going after they stop.

The Danish research showed that people who combined four weekly workouts with the weight-loss drug liraglutide, known as Saxenda, had lower body weight and less body fat a year after stopping treatment than those who used Saxenda alone.

Both groups regained some weight, but the exercisers put on an average of 2.5kg compared with 6kg for the non-exercisers.

Those who took part in cycling and circuit training sessions generally maintained their routines over the following 12 months, suggesting the habit lasted.

Lead author Signe Sorensen Torekov, from the University of Copenhagen, said: “The study almost makes me want to advise against medical treatment without increased physical exercise.”

Professor Alexander Miras, an obesity expert at Ulster University, says: “It's the strongest evidence we have that exercise is key to maintaining weight loss.

“It doesn't work by burning more calories, but by reducing appetite and energy intake.”

Zoe Griffiths adds that many studies suggest around an hour of daily activity is needed to help prevent regain.

“It doesn't have to be high intensity or done all at once,” she says. “It could be walking, swimming or any activity that gets you slightly out of breath but you can still hold a conversation.”

BUILD MUSCLE

One drawback of the injections is that they do not just reduce fat.

Between 20 and 50 per cent of the weight lost can be muscle mass, which makes strength training important during and after use. Muscle also burns calories when the body is at rest, so it helps with keeping weight off.

More lean muscle may also help suppress appetite, Zoe Griffiths explains, because muscles absorb glucose from the blood, steadying blood sugar and reducing cravings linked to spikes and crashes. “Your body does everything it can to regain weight by increasing your appetite,” she says.

“If you counteract that with more movement and lean muscle mass, that may minimise appetite changes when you come off the drugs.”

It has been a year since Ellen Ogley stopped using her Mounjaro pen after losing 3st — but instead of regaining the weight, she has gone on to lose another stone.

The 42-year-old nursery manager from Yorkshire, who once weighed 16st 12lb, dropped several dress sizes after the jab silenced her constant “food noise” — the intrusive thoughts about eating that had her repeatedly raiding the snack cupboard.

But Ellen knew that once she stopped taking the drug, maintaining the loss would be up to her.

She began strength training to rebuild muscle after, as she puts it, becoming “too skinny”, and replaced the two or three weekly takeaways she once had with healthier, high-protein meals.

The mother of three says her old eating and drinking habits developed after she was diagnosed with cervical and ovarian cancer and underwent a hysterectomy.

“I drank too much and ate for comfort,” she says. “I told myself, ‘If I come out the other side, I’ll take control of my health.’”

Now, a year after her final Mounjaro injection, Ellen is not only holding onto her weight loss but is a stone lighter than when she stopped.

“I have abs at 42 — it blows my mind,” she says.

“I hope it shows others they can maintain their weight loss after coming off the drugs.”

Professor Strain says there is no need for a gym membership: “Do squats while you're watching TV, stand on one leg while cleaning your teeth, carry a couple of tins of beans around with you. These things are just as good, if not better, than a gym membership because you're more likely to build them into a habit.”

EAT MORE PROTEIN AND FIBRE

For many people, the injections quieten so-called “food noise” — the constant cravings and thoughts about eating.

The downside is that this often returns within weeks of stopping.

Experts say it can be managed by eating more protein and fibre, which help people feel fuller for longer. Both may also prompt the release of natural GLP-1 hormones in the gut that tell the brain you are full — the same hormone mimicked by the injections.

Professor Naveed Sattar says: “You can start adding these things in while you're still on the jabs, when the food noise is quieter. It's a chance to think about what you eat and broaden your diet.

“Fibre really helps with weight control. It acts as the gut's lubricant, but you also have to chew it more for the same calories, and it may trigger satiety hormones naturally — not a huge amount, but enough to make a difference.”

Good fibre sources include lentils, chickpeas, wholegrain pasta, rice, oats, broccoli, carrots, apples and nuts. Try to include protein at every meal — eggs or yogurt at breakfast, and lean meat, fish, beans or lentils at lunch and dinner.

Professor Alexander Miras adds: “The best way to maintain weight loss is by following a high-protein, low glycaemic index diet — a bit like a Mediterranean diet with fewer carbs.”

SNACKING CAN HELP

Snacking is often blamed for weight gain, but it can also help reduce cravings.

Zoe Griffiths suggests eating regularly to “stay one step ahead of hunger”.

She warns, however: “Eat the right things which will keep you sated but won't be too high in calories. That may mean being organised and planning your snacks — ideally something that combines protein and fibre.”

Ideas include low-fat Babybel cheese with sliced peppers, a fruit or vegetable smoothie with milk, chia seeds or flaxseed, or plain Greek yogurt with berries and seeds.

USE 'URGE SURFING'

If you are worried about overeating when appetite returns, experts advise practising with smaller plates while still taking the injections so you become used to smaller portions.

Professor Sattar recommends filling half your plate with salad so you eat less of everything else while increasing fibre intake.

“You'll maybe have three or four fewer chips or a bit less pasta, but these things add up,” he says.

“I know I always have to have something sweet with my cup of tea, so I have half a biscuit, or half a piece of cake. It's not about avoiding your triggers but learning to moderate them.”

Or try what Zoe Griffiths calls “urge surfing”.

“Think about whether your urge to eat is really about genuine physical hunger,” she says. “If it isn't, think about it as a wave which will repeatedly crash on a beach. Visualise yourself riding it, but not responding to it and see how you feel in five minutes' time.

“That, in itself, can reduce or remove the craving, and you may feel better that you moved beyond it and didn't act on it.”

SLEEP WELL

Poor sleep can encourage weight gain and lead to fat accumulation.

One study found that getting just four hours of sleep for two nights in a row reduced levels of the satiety hormone leptin by 18 per cent and increased the hunger hormone ghrelin by 28 per cent. As a result, people craved calorie-dense foods.

Professor Sattar says: “If you sleep well, you put on less weight. Sleep helps appetite control, and gives you the energy to be active. If you don't sleep well, you crave the sorts of foods that give you a quick energy boost but are high in sugar, and will make you put on weight.”

Aim for seven to nine hours of sleep by avoiding screens before bed, making sure your bedroom is cool and dark, eating your last meal early, and exercising.

TRY WEIGHT-LOSS MEALS

Several companies now offer calorie-controlled meals and snacks that are nutritionally balanced and come in small portions — something Professor Sattar says may help.

One, The 1:1 Diet, formerly the Cambridge Diet, has proved especially popular among people using the injections or coming off them.

A study found that participants were able to maintain their weight loss for up to three years by returning intermittently to the plan and eating three meals a day totalling about 800 calories for five weeks whenever they regained a few pounds.

Its nutritionist Mark Gilbert says: “It's definitely something people can do to maintain their GLP-1 losses.

“I'd be shocked if people taking the drugs weren't deficient in some vitamins or minerals simply because they're not eating enough.

“This way, they get all their nutrient requirements plus essential fats and high-quality protein.”