The truth about weight-loss drugs

GLP-1 medications, such as Ozempic and Wegovy, have dominated health headlines of late. By mimicking a natural hormone in your body called GLP-1 (glucagon-like peptide-1), these drugs are proven to suppress appetite, leading to reduced calorie intake and weight loss.

However, new research reveals how our genes influence weight, why people can’t rely on GLP-1 medications alone, and the smarter approach to feeling happy and healthy – regardless of the number on the scale.

As Les Mills Instructors, you know better than most that fitness isn’t about fitting into a specific size or weight. Yet, for some, maintaining a healthy weight can be a crucial part of overall well-being. A healthy weight can reduce the risk of serious conditions like heart disease, type 2 diabetes, high blood pressure, and certain cancers.

But it’s not always as simple as “move more, eat less.” Science shows that some people are up against biology itself.

“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 influence weight. This research reinforces what many Instructors see in their classes every day: health isn’t just about willpower – it’s about understanding and working with your body.

Genes and weight: The science

Our DNA is a sequence of molecules that shapes everything from hair color to weight. Dr. Giles Yeo, professor of molecular neuroendocrinology, highlights the role of the FTO gene – sometimes called the “fat mass and obesity-associated gene.” He explains, “Fifty percent of people have at least one risk copy of FTO, and on average, they’ll be 1.5 kilos heavier than average. With two copies, it’s 3 kilos.” But here’s the good news: exercise helps offset that burden. “Those with FTO benefit from exercise – it can halve the genetic weight burden. We don’t fully understand why, but the results are real.”

This is a crucial insight for Instructors: your classes are more than workouts – they’re a powerful tool for people to reclaim control over genetic influences.

GLP-1: A powerful tool, but not the full solution

GLP-1 medications have quickly gained popularity. In the US alone, there’s been a 700% increase in usage over the past four years. But while these medications can kickstart change, they’re not a long-term “cure.” A University of Oxford analysis of 11 studies shows that most people who stop taking GLP-1 regain the weight within a year.

That’s where you, as a Les Mills Instructor, can make the biggest difference. People who combine GLP-1 with fitness and healthy habits see the most sustainable success.

Building habits that last

“Advice in a brochure isn’t enough,” says Bryce Hastings, Les Mills Head of Research. He recently led a study on habit formation, highlighting that coaching, support, and human connection are essential for lasting change. “We know that people are more likely to stick to exercise when they work out with others. That same principle applies to nutrition and lifestyle habits.”

As Instructors, your classes aren’t just about physical movement – they’re about creating a supportive community that helps people turn good intentions into lasting habits.

Strength training: A critical piece of the puzzle

One of the hidden challenges of weight loss – especially when using GLP-1 – is muscle loss. Many people lose not just fat but also lean muscle, which can slow metabolism and increase the risk of regaining weight later.

Resistance training is the answer. Research shows those who combine exercise with diet maintain weight loss better than those who diet alone. Scientists believe that exercise-induced myokines released by muscles may even help regulate appetite.

For your participants, this reinforces why strength workouts like BODYPUMP™ or LES MILLS STRENGTH DEVELOPMENT™ are essential for building a strong, healthy body that can sustain weight loss.

es Mills Trainer Kaylah-Blayr Fitzsimons-Nu’u

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Beyond the scale: A mindset shift

Les Mills Trainer Kaylah-Blayr Fitzsimons-Nu’u knows firsthand the power of shifting the focus from weight to performance. “I spent my whole life thinking I needed to get skinny. But when I started focusing on being the best athlete I could be, everything changed,” she says.

For your classes, this means celebrating what bodies can do – not just what they look like. As Kaylah-Blayr says: “Find what motivates you, what fills your tank. And then celebrate all the ways that exercise transforms your body and mind.”

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