Drinking juice - and only juice - for two months could earn you the title of fruit loop.
For Australian Joe Cross the extreme diet won him numerous awards, trimmed down his gut, and appeared to cure his debilitating autoimmune disease. But not everyone is won over, with an Auckland nutritionist warning of the dangers of cutting out whole food groups.
Cross, a former financial trader, is in Auckland to promote his award-winning documentary, Fat, Sick & Nearly Dead and campaign against processed food.
"When you eat food that is made by people in white coats ... you end up seeing people in white coats," he says.
A green juice concocted of celery, ginger and apples sits in front of him.
Aged in his mid-40s, he says he feels 21.
Rewind about five years and it was a different story.
Cross was 45 kg overweight, loaded up on steroids for an autoimmune disease and at risk from high cholesterol and diabetes.
Sex, exercise and holding a grocery bag were enough to inflame his chronic disease.
People were asking when the twins were due when a light bulb went on for Cross.
"Holy smoke: I'm actually carrying breakfast, lunch and dinner for probably six or seven months on my body," he says.
He decided to stop outsourcing his health to medical experts and ditch the pills for juice.
For the next two months, armed with a juicer, he consumed only fruit, vegetable, nuts and seeds.
Travelling across 5,000 kilometres in the United States, he filmed his journey to get off the pills and go healthy.
A little extreme maybe?
"The first three days I wanted to die, I thought I was an idiot," he says. "After five or six days I had never felt so good in my life."
His smell and sight improved, the tiredness went away and he cut out his medication, he says.
"You wake up in the morning and feel on fire, that's when it's worthwhile."
However, AUT nutrition professor Elaine Rush advises against extreme diets where food groups are removed.
"It would be very difficult to have a balanced diet. Where is the protein?
"He's not going to have normal gut action as there won't be much bulk in the diet to move on."
There is no evidence this diet would be beneficial for other people and could potentially be dangerous for people's health, she says.
Drinking only juice would also mean you miss the social aspect of enjoying meals with family and friends.
About one million adults - about one third of New Zealanders - are considered obese, according to the 2011-12 Health Survey.
Despite the nutritionists frowning on his juice diet, Cross says he hopes the film will encourage overweight people to taking on healthier lives.
"Somewhere between five and 15 days will benefit nearly everybody."
He refutes it is a diet, but rather a "reboot". He adds if you can splurge on fat and sugar over the Christmas period, why can't you splurge on juice and vegetables to reboot your body?.
Fat, Sick and Nearly Dead screens in a two-part series on TV One at 10.30pm on Sunday 27 January and Sunday 3 February 2013.
- © Fairfax NZ News