New Study Uncovers Unexpected Side-Effect of Popular Weight Loss Drug

Experts have discovered a surprising new health benefit of weight-loss medication – among people who haven’t even taken it. Research reveals a ripple effect when one person in a household uses the medication, with changes in their eating habits often influencing the whole household causing them to shed pounds too. It found more than 80% of households of those who have used GLP-1s (glucagon-like peptide-1 receptor agonists), which is a class of medications that mimic a natural gut hormone to treat type 2 diabetes and obesity, are eating healthier.

In a surprising twist, researchers have identified an unexpected health benefit associated with weight-loss medications that extends beyond the individuals taking them. A recent study highlights that when one household member begins using these medications, it often sparks a domino effect, leading to healthier eating habits throughout the home. The research indicates that over 80% of families with a member using GLP-1s—medications designed to emulate a gut hormone for managing type 2 diabetes and obesity—are now embracing better dietary practices.

Unhealthy habits

A survey conducted by Boots Online Doctor, involving 1,500 adults currently or previously on weight-loss drugs, revealed that these households are increasingly opting for home-cooked meals and incorporating more fruits and vegetables into their diets, with 77% reporting a decrease in takeaway consumption. Impressively, over 85% of families with children noted improvements in their kids’ eating habits, health consciousness, and physical activity levels when a parent used GLP-1s. These medications work by promoting insulin release, curbing appetite, and slowing stomach emptying, which enhances feelings of fullness, thereby aiding in blood sugar regulation and weight reduction.

Prior to starting weight-loss therapy, many families battled with poor dietary routines. More than half of the respondents admitted to frequently consuming sugary beverages and snacks (51%) and indulging in oversized portions (50%), with 45% regularly consuming processed foods and 43% leading primarily inactive lifestyles.

Dr. Anju Verma, who leads the Weight Loss Treatment service at Boots Online Doctor, explains, “Weight-loss medication can quiet the constant food-related chatter—cravings, portion dilemmas, and meal uncertainties—allowing individuals to cultivate a healthier rapport with food and exercise.”

Changing habits

The survey also found 80% of households are trying new, healthier recipes more often and enjoying more mindful mealtimes. About 74% have cut down on unhealthy snacks and processed foods, while over half are investing in movement through gyms, fitness classes or family exercise.

Nearly three-quarters report improved household connections, and in almost a third of households, other family members have also lost weight. Ruth Taylor, nutritionist at Boots Online Doctor, adds: “When someone in a household starts focusing on healthier habits, it naturally influences others around them.

“Framing changes around overall health rather than weight, and avoiding negative comments about body size, also helps children develop a positive relationship with food and activity.

“These small, mindful choices help the ripple effect reach everyone in the home.” Approximately 1.6 million adults in the UK used weight-loss drugs, such as Wegovy or Mounjaro, between early 2024 and early 2025, according to research from University College London. A further 3.3 million have expressed interest in using them with usage being twice as common among women and peaking in the 45-55 age group.

Expanding access

NHS England announced on April 1 it is expanding access to the weight-loss drug semaglutide (Wegovy) to an estimated 1.2million people with a BMI of 27 or higher, specifically to reduce the risk of heart attacks and strokes.

Boots Online Doctor encourages healthy habits alongside weight-loss medication and offers one-to-one coaching, expert clinical guidance and a 12-month aftercare programme. Access to treatment is subject to an online consultation with a clinician to assess suitability and charges apply

Lisa Kinnard, 46, was prescribed weight-loss injections last October after an initial diagnosis of Type 2 diabetes in 2024 following a routine over-40 health check-up. “It was a real wake-up call receiving that diagnosis but the initial treatment path was really challenging for me,” the office manager from Benfleet, Essex, says. “I’ve never been good with taking medication, and the drugs my GP prescribed made me feel unwell, making it hard to stick to the regime.”

Lisa found herself feeling very sick on her diabetes medication and meanwhile she was growing increasingly concerned about her weight. At just 5ft 2in, the petite mum of three weighed 13-and-a-half stone.

“I knew I needed a different approach so I tried to order Mounjaro online privately but they wouldn’t let me have it because of the medication I was already on and referred me back to my GP. I was emotional at my GP appointment, pouring out my struggles with medication side effects, my weight, and admitting my attempt to try and get the injections privately.

“I admit the floodgates opened. However, my GP’s response was sympathetic and, after reviewing everything, she confirmed I qualified for weight-loss injections through the practice. That validation felt like a new beginning.”

Lisa started her weight-loss injections with a 2.5mg dose, gradually increasing it and is currently on 7.5mg. She injects herself once a week with the drug and is reviewed every three months now.

“The changes have been profound. I’ve successfully lost two-and-a-half stone but the impact goes so much deeper” she says. “Earlier this year, my GP delivered amazing news. I’m no longer even in the pre-diabetic range.”

Lisa’s daughters have also benefitted from their new-look, healthy mum. Twins Molly and Lilly, aged 20, and her youngest daughter Lola,18, are feeling the knock-on benefits of her healthier lifestyle. Lisa says: “I used to buy unhealthy snacks, often telling myself they were for the kids, but I’d end up eating a lot of them myself. With my new relationship with food, those unhealthy purchases have drastically reduced.

“My daughters encourage me not to buy unhealthy snacks and it’s created a much more health-conscious and less snack-driven environment for all of us.”

Lisa’s husband Adam, 49, a director in the construction industry, is also fully on board with the family’s new eating habits. “My youngest daughter is tiny anyway, but the other two have lost a bit of weight but the main thing is we all feel much healthier and are exercising more. We go on walks as a family with the dog and all feel so much better,” says Lisa.

“I am aiming to try and lose another 7lb in the next three weeks or so ahead of a family holiday to Ibiza.”

Lisa says her weight-loss success has given her mental health “a huge boost” too, which again has had a knock-on beneficial effect on her husband and daughters seeing her healthier and happier.

Long-term she says she has “a much more mindful relationship with food now”. She expains: “While I still have the odd cheat day, my general approach to eating is far more careful and intentional.”

And the whole house is now reaping the rewards from a less snack-driven and more health-conscious approach to food. “I still buy the odd treats now but I am finding they sit in the cupboard for much longer because none of us are so tempted anymore as we are all out of that habit of eating junk.”

She is also more active, swimming three miles a week and doing water aerobics. Her daughters play lacrosse and go to the gym while Adam plays golf. “These injections have allowed me to reclaim my health, my confidence, and has brought a renewed sense of wellbeing to our entire family.”