It's for this reason that Bolton, a motivational speaker specialising in lifestyle change, believes we should worry less about shrinking the numbers on the scales to lose weight and more about body composition. "Muscle might weigh more than fat but it takes up less space – a kilo of muscle is about the same volume as a small or medium vegemite jar but a kilo of fat fills the same space as a wine bottle," he says. Women can't change their biology but they can improve the odds of maintaining a healthy weight or losing weight by building more muscle – or at least hanging on to the muscle they have. The same goes for men. "If you don't exercise, from about age 30 onward you'll likely lose on average around 200 grams of muscle a year - so over a 10-year period your metabolism will gradually slow down. But if you can keep the same amount of muscle at 40 that you had at 30 it will be easier to maintain a healthier weight," he says. Building more muscle with weights is one way but it's also about being more physically active generally and looking at the job of lifting and carrying in daily life as a way to maintain strength – not something to shy away from.

Appetite hormones can make a difference too. "Research has found that compared to a man a woman's appetite is more likely to be stimulated after exercise – the reason many women eat more after exercise may be more about appetite hormones than willpower," says Professor Philip Morgan, co-director of the University of Newcastle's Priority Research Centre in Physical Activity and Nutrition. Still that doesn't mean weight loss for men is always straightforward - if it were then 70 per cent of Australian men wouldn't be overweight or obese. First they need to realise that their weight is a problem – and for some men this is a penny that's slow to drop, says Morgan who helped design Workplace POWER (short for Preventing Obesity Without Eating like a Rabbit), an award winning work-based program that helps male shift workers lose weight. "Although most men carry too much weight, many don't see this as a problem and may not be aware of the health consequences," he says.

One reason for this he says is our notion of masculinity in Australia which assumes that men are emotionally and physically strong, are stronger if they are bigger, and are prone to risky behaviours - including not being worried about the health effects of what they eat. "Meanwhile women are often set up from an early age to believe their appearance is of primary importance – it shouldn't be this way but it often is," he says. "Studies show that men may be slower to recognise that they're overweight and that they're less likely to enrol in weight loss programs – partly because weight loss has been feminised and most programs don't account for physical, psychological and cultural differences between men and women. But once men decide they need to lose weight, studies have shown that being male can make weight loss easier. "Men generally have less emotional baggage around eating and weight loss. But with women it can be more complicated. It's true that some men do have eating disorders but in general eating disorders and restrained eating are more common in women. "I think this is why a one- size- fits-all approach to weight loss doesn't work – we need to consider gender differences too."