While you don’t need to conform to a specific size or weight to be fit and feel good, for some, taking action to maintain a healthy weight is a smart move. A healthy weight is key to overall health and helps prevent and control serious health problems like heart disease, type 2 diabetes, high blood pressure and even certain cancers.
Unfortunately, it's not always as simple as eating less and moving more, science suggests some people are fighting biology every step of the way.
“We have far less control over our weight than we might wish to think,” says Professor Sadaf Farooqi, lead researcher of a University of Cambridge study exploring how genetic variations increase the likelihood of being overweight. This insightful research highlights how maintaining a healthy weight is not simply a matter of better willpower or smarter lifestyle choices. “Healthy thin people are generally thin because they have a lower burden of genes that increase a person’s chances of being overweight,” says Professor Farooqi.
The Genetic Spotlight:
Our DNA comprises a sequence of molecules strung together to make up our genes. Changes in how the molecules are strung together can determine subtle or sometimes dramatic changes in features such as hair color, eye color, and weight.
Dr Giles Yeo, professor of molecular neuroendocrinology, says there are various genes that influence weight, one in particular is the FTO gene (also known as the fat mass and obesity-associated gene). FTO is a complex molecule that acts as a protein sensor, with subtle influences that regulate energy balance, and trigger hunger and food intake. He explains, “Fifty percent of the human species carries at least one risk copy of FTO, and on average, the person who has one FTO is 1.5 kilos heavier than average. If you have two copies, you’re three kilos heavier.” What’s particularly interesting is that, unlike other genes that influence weight, the FTO gene is also responsive to exercise. “If you have two copies of this gene you’ll be, on average, three kilos heavier, but if you exercise, you’ll reduce your genetic burden by half – you’ll only be 1.5 kilos heavier than average. This means that those with FTO have the benefit of being able to mitigate against their genetic burden. We don’t know why, and it’s going to be complicated to find out, but the results are real.”
The increasing appetite for GLP-1
Those struggling to lose weight with diet and exercise alone, now have a new tool on hand. GLP-1 medication. This game-changing medication mimics the natural GLP-1 hormone to improve health by promoting weight loss, managing diabetes and reducing cardiovascular risk.
GLP-1 has already transformed the lives of millions.
Although relatively new, GLP-1 has already transformed the lives of millions. Over the last four years, the US alone has seen a 700% increase in overweight individuals using GLP-1 medication to improve their health.
However, a University of Oxford analysis of 11 studies (presented at the 2025 European Congress on Obesity) highlights how most using weight loss drugs regain all the weight they have lost within a year of stopping the medication.
Many consider it a ‘miracle cure for obesity’, but it is technically not a ‘cure’. In the same way blood pressure medication eases hypertension but doesn't cure it, GLP-1 simply treats the issue by supressing appetite. When you stop taking the medication, your appetite returns. And when it comes to GLP-1, many people stop. Cost and uncomfortable side-effects are two of the main reasons people find long-term GLP-1 use unsustainable. It is estimated that up to 50% of patients abandon treatment during the first three months.
Most using weight loss drugs regain all the weight they have lost within a year of stopping the medication.
Those who enjoy the best results from GLP-1 medications do so because they combine the medication with other life-changing actions and establish long-term healthy habits.
Coaching, support and a smart approach to habit-building are key
Medical professionals recommend GLP-1 patients pair the medicine with a healthy diet and increased physical activity. But it’s hard to force people to follow this guidance. "In most cases, the advice and guidelines are in the format of a basic brochure – and when it comes to embedding healthy habits, reading a brochure isn’t going to cut it,” says Bryce Hastings, Les Mills Head of Research.
Hastings has recently led a comprehensive study examining the science of habit formation, and the value of combining different habit-forming strategies to ensure success. This is supported by new insights spelling out how combining health and well-being coaching with a GLP-1 prescription is likely to improve medication adherence and promote healthy behavior change.
“Planning and preparation are key, and you can’t beat the human element,” says Hastings. “We know that people are more likely to adhere to regular exercise when they work out alongside others, and it makes sense that personal support helps motivate others to maintain further healthy lifestyle changes aligned with their best selves.”
Strength training – the other GLP-1 essential
When you lose weight, it’s not just fat that disappears – many people on GLP-1 medication typically lose muscle mass too. Sparking muscle growth with a routine of consistent resistance workouts is fundamental to counteracting this muscle loss.
Maintaining muscle mass is important as it will help you avoid weakness and mobility issues, as well as a drop in metabolism. What’s more, evidence suggests loss of lean muscle tissue during weight loss bumps up the risk of weight regain in the long term. This is backed up by another study of overweight policemen who spent two months taking action to lose weight. Half the policemen focused on diet alone and half combined diet and exercise. While both lost weight, it was only those who exercised who maintained their weight loss beyond the initial two months. Although more research is required, scientists suspect that our drive to eat may be influenced by the release of myokines from muscles during exercise. These hormones interact with brain centers generating appetite suppression.
Focusing on what’s important…
Kaylah-Blayr Fitzsimons-Nu’u is a Les Mills Trainer who spent years wanting to be skinnier. “Body image has always been one of my biggest hurdles … I spent my whole life thinking I needed to get skinny… but trying to get ‘skinny’ had never worked for me.” When she realized she’s just not built to be thin, yet she can still be strong, beautiful and successful, it was life-changing. “I went from thinking ‘I need to get skinny’ to thinking ‘I want to be the best athlete I can, so I can perform’. I gave myself a new goal of wanting to be the best athlete I could.”
For Kaylah-Blayr, making a shift in mindset was truly transformational. She is living proof that focusing on all the wonderful ways exercise will help your mental health and improve your life can be much more life-changing than shedding a few pounds.
“There are different types of motivation that appeal to different people,” she adds. “Find what works for you. Figure out what fills your tank, and what makes you want to get moving. And then celebrate the many and varied ways that exercise transforms your body and mind."
