“Studies found that people [on Wegovy] lost 9.6 per cent of their weight over 68 weeks, while with Ozempic they lost seven per cent over the same period,” Sumithran explains.
So what happens if you stop taking semaglutide?
“Like all medications for long-term conditions, semaglutide only works while you take it so most people will regain some weight if they stop. Exercising regularly and continuing with the eating plan does help maintain weight loss if you stop semaglutide – but it’s hard to maintain the same eating habits in the long term if you stop a medication that helps control your appetite.”
However, demand for semaglutide has created such a shortage that stocks of the drug won’t be available in Australia until the end of March, according to the Therapeutic Goods Administration.
But as Newton points out, weight loss by any method that involves taking in fewer kilojoules than you burn can result in muscle loss if we skip exercise. Some of us are more at risk than others – serial dieters who’ve tried repeatedly to lose weight can forfeit considerable muscle over time, he says.
“Muscle loss caused by repeated dieting without exercise is one reason why it can be hard to maintain long-term weight loss. When we lose muscle, we lose active tissue that’s one of the body’s main users of kilojoules. Even when we’re at rest muscles are still consuming kilojoules,” he adds.
“Fast weight loss induced by very low kilojoule diets like juice or cabbage diets can accelerate muscle loss. Women are more at risk than men because they generally have less muscle to begin with. The same goes for older people who have a lower muscle mass due to ageing, especially if they’re inactive.
“Geriatricians understand this because they see the end result of gradual muscle loss – frailty and problems with mobility. It’s a slippery slope that ends with loss of independence.”
But it’s not just mobility that’s threatened by muscle loss. Muscle produces a range of hormones and other substances that benefit all our body’s systems, while excessive fat does the opposite – secreting hormones and inflammatory chemicals that undermine our health, Newton explains.
“Fat and muscle are like yin and yang, but with overweight and obesity these two different tissues are out of balance, and the influence of hormones produced by fat overwhelms the benefits of muscle. That’s why body composition – the right balance of muscle and fat – matters more than weight alone.”
What are the signs you might be losing muscle?
“When you find that tasks that used to be easy – like putting out the garbage or lifting the mower out of the boot – are getting harder,” Newton says.
“The best defence is strength training and you don’t have to go to the gym – you can do bodyweight exercises that target large muscle groups at home like squats, lunges and push ups two or more times each week.”
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