Fitness guru James Duigan thinks it's time men took their health seriously.
Sedentary lifestyles and poor diet mean too many of us are overweight and unfit.
Women tend to be more conscious of their health, Duigan says, while men too often take a "she'll be right" attitude.
After writing several best-selling books for women, he has now produced one for men, Clean and Lean Warrior (Kyle Books, $29.99), which combines nutritional advice with exercises and recipes.
Duigan was motivated to write the book after his father was diagnosed with lung cancer. Duigan senior has since beaten the disease.
"I wanted to provide a resource for men and allow them to feel, 'okay I can buy this book and have a look and figure out how to be healthy'," James Duigan says.
Duigan was born in the UK, raised in Australia and now runs the exclusive Bodyism gym in London where his clients include Elle Macpherson and Hugh Grant.
He started as a personal trainer then became interested in nutrition. His "clean and lean" approach combines the two.
He argues you can't lose fat and gain muscle efficiently if your system is loaded with toxins such as sugar, alcohol, caffeine and processed foods.
"I want to change the meaning of the word 'diet' because diets don't work," Duigan says.
"Statistically they are the fastest way to put on weight.
"I want to change it back to what it truly means, which is how you live and how you eat forever."
One thing holding men back, says Duigan, is the idea that caring about one's health is unmanly.
"For all of us, but for men especially, there is a lot of shame and guilt about food and health and feeling like, 'oh I shouldn't bother so much, it makes me a bit wimpy'," he says.
"I want them to embrace it and say, 'of course I've got to look after myself'.
"Any transformation in their body happens in their mind first.
"They have to get comfortable with the fact they deserve to feel good and look good and that it is very easy and achievable."
Duigan says exercise and diet are equally important.
"People say to me, 'which is more important?' It's 100 per cent about your attitude and a holistic approach.
"Once you realise that how you eat and move aren't separate things - it's about how you live your life, then transformations happen very quickly and you start feeling better within a few days.
"It's incredible how fast it happens."