For over 30 years, Dr Campbell has passionately promoted a holistic approach to weight management. He was the show doctor on three seasons of ITV’s Biggest Loser and works closely with Nutracheck to help our members live healthier, happier lives.
Many of us feel like we’re doing all the right things – eating well, moving more – but still not seeing the same weight loss results we did in our 20s or 30s. So, is it true that weight loss gets harder as we age? And if so, why?
To help separate fact from fiction, we asked Dr Ian Campbell to share his expert insight on what’s happening in the body as we get older – and the practical steps we can take to manage our weight effectively at every stage of life.
Is it harder to lose weight as we age?
“Unfortunately, yes – and there are several reasons why,” says Dr Campbell. “From our mid-30s onwards, many people begin to notice a gradual change. That might mean gaining just 1kg a year – which doesn’t sound like much, but adds up over time.”
This gradual gain is often paired with a growing sense that weight loss takes more effort than it used to. “Even when people stick to healthy eating and stay active, they can feel like the results are slower. That’s because our bodies are changing – hormonally, physically, and psychologically.”
What happens to our metabolism and muscle mass?
As we age, our metabolism naturally slows. “That means we burn fewer calories at rest – so we need slightly less food to maintain the same weight,” Dr Campbell explains.
Muscle mass also plays a key role. “From around the age of 50, we start to lose about 1% of our muscle mass every year,” he says. “Less muscle means a lower resting metabolic rate – which makes it harder to manage weight. That’s why maintaining muscle through strength-based activity becomes even more important as we get older.”
How do hormones affect weight?
Hormonal shifts can significantly affect how our bodies manage weight – in both men and women. “For women, the perimenopause can start as early as the 40s and lead to an average weight gain of around 1.5kg per year, or a total of 10kg by the time they reach postmenopause,” Dr Campbell explains. “Falling oestrogen levels are partly to blame – they can reduce metabolic rate, affect energy, and make weight gain more likely. HRT can sometimes help, but it’s a personal decision that should be discussed with your doctor.”
Men also experience hormone-related changes. “Testosterone levels begin to decline gradually from around 30-40 years old. While the change is subtle, low testosterone can increase appetite and fat storage – especially around the waist,” says Dr Campbell. “Interestingly, losing weight can help raise testosterone levels, creating a positive cycle.”
What about lifestyle factors?
It’s not just about biology. “As our lives change, so do our habits,” says Dr Campbell. “We might move from active roles to more sedentary ones. Stress builds – from work, family, finances – and we may exercise less, sleep poorly, or turn to fast food more often. These things all make weight management harder.”
Sleep, in particular, is a hidden factor. “Getting at least seven hours of good-quality sleep is linked to a healthier weight and better lifestyle choices.”
Why does it feel like the same strategies no longer work in later life?
“As we age, doing exactly what we did in our 20s or 30s might no longer cut it,” says Dr Campbell. “Our energy needs are lower, our body composition changes, and our hormones behave differently. It’s not that we’re doing something wrong – it’s that our bodies need a slightly different approach.”
So, what does work for weight loss after 40?
“The fundamentals remain the same,” Dr Campbell reassures us. “A healthy, calorie-controlled diet that’s rich in nutrients, fruit and veg, and higher in protein is important. Cut down on added sugars, cook more meals at home, and move as much as possible – ideally 150 minutes of brisk walking a week.”
He also recommends focusing on resistance training. “Strength-based activity helps maintain muscle, supports metabolism and can really improve how we feel, especially alongside cardio exercise.”
Dr Campbell also emphasises the power of peer support. “People who try to lose weight with a friend or partner are much more likely to succeed. And if stress or fatigue are big factors for you, don’t be afraid to seek help – whether that’s from mindfulness techniques, social support or medical advice.”
When to speak to your doctor
“If you’re finding things especially tough, it’s worth ruling out underlying issues,” says Dr Campbell. “A common one is hypothyroidism – a low thyroid hormone level that can cause weight gain and fatigue. Low B12 levels can also affect mood and energy, making weight loss more difficult. These are simple blood tests your GP can arrange, so it’s worth asking for advice if you’re concerned.”
While testosterone supplements are rarely needed, and not suitable without a diagnosis, your GP can also check hormone levels and guide you based on your results. And for women struggling with the menopause, your doctor can advise whether HRT might help.
Final thoughts
“Weight loss might feel harder as we get older, but it’s still achievable – and still hugely worthwhile,” says Dr Campbell. “It’s about adapting your approach, not giving up. Focus on the basics: nutritious food, movement you enjoy, strength training, good sleep, and stress management. The effort will pay off.”
Expert opinion
“Weight gain with age is common – but not inevitable. A slower metabolism, changing hormones and muscle loss can make weight management harder, but the same principles still apply. Adjust your habits to suit your body’s new needs, and you can lose weight and improve your health at any age.”
