Lowdown on the OMG diet; Fancy skipping breakfast in favour of a cold bath? Venice A Fulton's Six Weeks To OMG plan challenges everything you thought you knew about healthy eating. Kirstie McCrum talks tactics the diet's creator.
* ET'S get it straight from the start: Venice A Fulton's new creation, Six Weeks to OMG: Get Skinnier Than All Your Friends, is a gruelling regime.
Named by one newspaper as "the publishing sensation that is rivalling the Dukan", it's grabbed many headlines with its The Only Way Is Essex-referencing tongue-in-cheek subtitle - a creation of the publisher, insists former personal trainer Venice - and even more with its frankly unpleasant-sounding regime, which includes plunging oneself into a chilly bath in the morning, skipping breakfast and drinking black coffee.
Starting out life as a self-published e-book, the work of Venice - aka Paul Khanna - marks a step change from his degree.
"My background is sports science, which involves anatomy, physiology, nutrition even psychology to make better athletes," he explains. "But athletes will do anything you tell them to and now I want to work with the rest of us."
He acknowledges it's not easy, but he's here to help decode diets for everyone.
"The idea of the book was to use research - new research and some old research which had not been used effectively - and to get it across in a way that the reader understands," he adds.
The most alluring thing about the diet is how easy it is to incorporate into your daily routine, detailing measures to take from the second you get up, but not including the facts with complicated calorie-counting, meal plans or recipes.
But what OMG does offer will be a rude awakening.
"A cold bath will kick start your metabolism, but it's not the only measure in the book," he insists.
"Anyone who is scared of a cold bath should think about walking around with a sluggish metabolism, having less energy than you need or less self esteem than they deserve."
The science behind Venice's 'skinny dipping', as he calls it, is actually fairly straightforward.
"If you walk into your bathroom naked, you lose heat at a certain rate. If you jump into bath at the same temperature as the air, you lose heat 25 times faster, so your body ramps up its own heat production.
"The energy for that will predominantly come from burning body fat, which in some people could mean an increase in metabolism that can last for 12 to 15 hours.
"Jumping in a cold bath is not sensible if you do not follow an exact structure, so you should read the book before you do it. You do have to be in good health, and it's advisable to have a bath thermometer to monitor the temperature."
Another eyebrow-raising claim is that missing breakfast will help you lose weight, a regime which seems to fly in the face of all previous advice from nutritionists.
"Skipping breakfast is key. For the past two million years, that's what we've been doing as a species and we're still here, so it's safe to say that it won't kill you.
"In the last 200 years, we've been having breakfast and we've seen a slow but steady increase during that time in both sickness and obesity.
"When you're asleep, your body is still awake carrying out functions. That takes energy and when you wake up, all of your energy is gone. In that state you have a once a day opportunity to tap into your body fat as a fuel. If you delay your breakfast by two or three hours and go about your daily activity, you'll be using body fat as a fuel.
"If you don't start using that and you rely on traditional breakfast, your body will not use that body fat."
Venice says that critics who insist that skipping breakfast is associated with eating more later in the day or being heavy remain unproven.
"Lots of people say that breakfast is necessary to kickstart your metabolism, which isn't true. If you want proof, look around the world where billions of people eat breakfast to kickstart their metabolism and still remain fat."
Something Venice is adamant about introducing into the diet may leave a fairly bitter taste for some - black coffee.
"Whether you like coffee or not, it's a great ally in the war against fat. It's a naturally rich source of caffeine, which works by increasing your metabolic rate.
"You must have your coffee without milk or sugar because they raise insulin which tells your body not to use its fat stores.
"Coffee early in the day means your metabolic rate increases early on and you maintain that level for your waking hours. You need it no more than once or twice a day, otherwise your body will get used to it."
But while you're having that coffee, don't even think about adding a snack - however 'healthy' you think it is.
"There are no healthy snacks - there are healthy foods which contain things you need, but none of them are healthy if you consume them in between meals.
"When a calorie or taste passes your lips, it tells your body that food is coming in, which produces insulin. Insulin's job is to take stuff out of the bloodstream and put it into cells. When it's going into cells, nothing can leave cells, including stored body fat, so when you snack in between meals, you will no use stored body fat as a fuel. The key is to leave gaps of three to five hours between meals because all food takes time to digest."
* Six Weeks To OMG: Get Skinnier Than ALl Your Friends is published by Michael Joseph/Penguin priced pounds 12.99.
FAD OR FABULOUS? Rhiannon Harris, right, senior lecturer in nutrition and dietetics at the Cardiff School of Health Sciences at Cardiff Metropolitan University, says that she has reservations about what the diet promises.
"I haven't read the book, but from what I've read online I've got some real concerns. It is the next fad diet.
"The 'get skinnier than all your friends' tagline worried me - I think titles like that have an impact for teenagers.
"The biggest concern I have is how can people keep on this diet for a long period of time? It's not sensible eating.
"We want to encourage people away from yo-yo dieting, or weight cycling. We want them to eat a healthy diet, maintain it and lose weight slowly and steadily.
"That's really the only long-term way to have a healthy diet and reduce your Body Mass Index.
"Plunging yourself into cold water every morning probably does stimulate your metabolism - it would certainly stimulate mine! - but nobody's going to carry on doing that endlessly.
"For youngsters especially, but for adults as well, having breakfast is crucial. It breaks that overnight fast.
"There are studies with a reasonably large population base that show people who have breakfast tend to have lower BMIs.
"If you don't have breakfast by about noon you are starving, which means you might snack or eat larger quantities of food than you would have if you had eaten breakfast. I think skipping it flies in the face of the Food Standards Agency's healthy eating plate which shows the balance of good health.
"Looking at positives from the diet, I do think that limiting fruit juices is quite a good idea because juice counts only once towards your five a day, so you can't have, say, five glasses of orange juice a day.
"Coffee is a stimulant and we take it when we're a bit sluggish. We're used to having caffeine in our diet - large quantities are not particularly helpful, but if it's a small amount I don't see a problem.
"The bottom line for health is that we want to see people having a balanced diet. It's so sad that people seem to impatient to lose weight that they can't follow a standard diet.
"I can't see people following it. I think they'll go on it for a while, lose some weight, then when they stop it'll go back on. How can you get skinnier than all your friends - we all have a different shape and bone structure, we all have deposition of fat in different placers.
"You need to concentrate on your own BMI and making your own diet as well-balanced as possible."
Venice A Fulton