The rise of boot camps and TV programs such as The Biggest Loser are encouraging men to opt for a quick fix to weight and body image problems, with six, eight or 12-week "fat to fit" programs increasingly popular.
"They're a lot more common I think because they follow the boot camp phenomenon," says Matt Thom, founder of Fitness Kick and former winner in pairs fitness at the World Fitness Federation Universe Competition. "They're popular because they're quite intensive."
The fast track to a new body is marketed as the fast track to a new life, but does the reality match the hype?
"The market has shifted towards men," says Mike Jarosky, personal trainer and author of 40 Days as a City Caveman. "Overhaul, get ripped. New body, new life, and so on. A lot of this is perpetuated from Hollywood as well.
"So what we see on TV, magazines, the net, has raised the bar for an ideal physique. We're becoming a nation of extremes. We're either obese as the statistics say, or we are ultra-fit.
"Bigger cars are better, bigger homes are better, bigger bank accounts are better, bigger boobs, and so on ... so aren't bigger muscles better too?"
For 42-year-old gym owner Tony Cordin, transforming his body was as much about self-esteem as physique.
"I had elements of depression," he says. "My body was reflecting my mind. It was a slippery slope."
Stressed, depressed and caught up with work, he had not noticed his body slowly ballooning. "I went from training every day to rarely training, but still had the belief that I was an exerciser," he says.
After a holiday of eating and drinking indulgently, he didn't recognise himself, so when he saw an advertisement for a natural fitness/bodybuilding competition, he thought it was a good chance to initiate change.
With 12 weeks to prepare, he broke his regime into three parts: "Acclimatisation – getting your body used to training again; building a foundation of strength and developing muscle; and then cutting up."
He says he exercised for only 30 minutes a day, five days a week, and while in the lead-up to the competition he cut carbs and was dehydrated, he insists his transformation was healthy and has made him happier.
"Now I'm sharp as a tack, as good if not better than I was in my 20s," he says. "It's sustainable – [I ate] meat, vegetables and brown rice. I wasn't sitting down with a dry celery stick and crying about it."
Thom says a two-pronged approach to diet and fitness is the key to making a kickstart program last.
"If the nutrition plan isn't right you won't go from fat to fit. A good body is made in the kitchen and polished in the gym."
Jarosky says the changes must be manageable if they are to be maintained, otherwise such transformations are just another fad.
"If somebody prescribes a quality diet with fresh, healthy, and tasty food mixed in with an exercise plan and education about why you are doing what you are doing? Then yes, this can lead to positive lifestyle change in the short and long term."
It is what Jarosky, who went from fat to fit in just 40 days, self-prescribed.
"My lifestyle was one of [an] energy drink for breakfast, mall food for lunch, convenience store snacks, pub food for dinner and drinks with no exercise, and bad sleep," he says.
"I simply looked at each element and made a healthy plan to turn each one of those things around – a healthy breakfast, water, fruit/veg, a lot less booze, salmon/spinach and quality exercise with better sleep.
"I didn't know what was going to happen, but I just believed in making an investment in my health so I could avoid diabetes, heart disease, and the serious weight gain I was experiencing. My body absolutely loved the change, and it responded quickly."
In spite of the positives, fast body overhauls are not always healthy.
"Red lights would be group training, or under the umbrella of boot camp and being yelled at," Thom says. "If you've gone from the couch to that, that's a red flag. It is just [starting at a] level that's way beyond them straight away.
"The injury risk can be quite high. Exercises should be personal-best-based – for instance, 'do push-ups for 30 seconds', not 'do 30 push-ups'. Everyone is different – there's not one formula for everyone.
"If you're going to get results, it needs to be individually focused and tailored. And there's a lot of bad nutrition advice out there."
Bad nutrition advice includes the popular protein push, Thom says.
"High protein obviously works, but is not sustainable for life – you can become a protein zombie. We need carbs and fats. Wholefoods takes longer, but you won't bounce back – it's a life thing."
Jarosky agrees. "I become more wary of overhauls that include protein supplements and other pills that are unnecessary when making a lifestyle change.
"Protein deficiency is not an issue in Australia, so overhauls that require protein are merely making big margins when you make that purchase. You don't need pills and powder – let food be thy medicine, right?"
Jarosky and Thom both believe that ultimately six, eight or 12-week body overhauls can act as a kickstart to positive, long-term change. But the focus should remain on consistency, not the quick fix.
"The biggest risk of these transformations are the 'I want it now' mentality," Jarosky says. "I preach patience rather than the 'now'. As long as you eat well, drink well, and exercise it's only a matter of time. Be patient, and it will come.
"Fat to fit can't be done with some pseudo light switch in your body, so you have to think about making small, positive changes in the short-term while committing yourself to a long-term, healthier you."