When it comes to weighing in, it appears we are a nation of heavy hitters. Australians are battling the bulge, but we're losing. In the last twenty years, obesity rates have doubled with one in every four adults so fat, they're considered Obese.

In the UK they're facing a similar epidemic and it's costing them dearly. "There has been a 29% increase in costs for providing knee replacements for people who have osteoarthritis from being obese and a 40% rise in the diabetes drug costs in five years. The costs are just going to be enormous and you just cannot allow that to happen", said one of the UK's leading weight loss medicos, Professor Anthony Leeds.

The poor state of our health has given rise to a $3 billion boom industry that often makes big promises to make you small. But among the fads, magic pills and exotic diets, there are ways to lose weight and keep it off.

But according to Professor Leeds, the first and most important hurdle when it comes to weight loss is mental. "The secret to losing weight is to be prepared and want to do it. One of the problems often is that they start the program when they are not really committed to it", he said.

Professor Leeds is in Australia to launch a modern version of the Cambridge Diet. The diet is a scientifically formulated eating plan originally designed by the Cambridge University professor in the 1960's, to help morbidly obese people lose massive amounts of weight so they could undergo lifesaving lap band surgery. "They are individuals that have developed a comfort eating habit, perhaps a failure to control portion sizes and the strong desire to always go back for a second helping", Professor Leeds said.

According to the Professor not all powdered diets the same. He says the Cambridge Weight Plan products contain all the micronutrients the body needs to function normally, they're just delivered with the lowest calorie intake possible. "The Cambridge Weight Plan would give something in the order of 15, 20, 25 even 30 kilograms weight loss in the period of 12 weeks", he said.

30-year-old Anna Shepard wanted to lose weight for her wedding. After 20 weeks on the Cambridge Weight Plan she's dropped 46 kilos. In fact she was so successful she now works for the company as an ambassador. "I've tried sensible diets, fad diets, but Cambridge was the one that worked for me", Anna said.

The reason this diet worked where others failed, according to Anna is due to the support from the Cambridge consultants. "Their number one aim is to make sure you get to your goal", she said.

"I turn to food when I 'm bored, I turn to food when I'm excited, it's just always part of my life and has therefore affected me", 27-year-old Roision Graham.

Roision has been battling her weight since she was a teenager. At 110 kilograms it's the heaviest she's ever been and the heaviest she ever wants to get. Her goal weight is 60 kilograms. "If I don't lose the weight then my life is just going to stay exactly the same as it has been which is quite frankly disappointing", she said.

After just one week on 500 calories a day, Roisin lost 4 kilos. "It keeps you motivated because you are seeing big losses each week", she said.

But dietician Melanie McGrice has a warning -- before starting a massive weight loss journey, you should first consult a professional. "People should be aware of any diet that isn't given to them by their GP or dietician", Melanie said.

For further information on the Cambridge Weight loss Program, visit the website at: <> or phone 1300 365 891