Move over Atkins!

It's been a constant gripe of calorie-counters - they eat healthily but the waistline keeps expanding. Now a new diet could be the answer to their prayers.

And unlike the Atkins plan - which advocates a high-protein food regime at the expense of carbohydrates - the GI Diet offers a balanced choice of foods.

Nutritionists believe a food's glycaemic index (GI) rating could hold the key for dieters who eat healthily but still fail to lose the pounds.

Foods are rated on a scale of one to 100 according to how quickly they break down from carbohydrate to sugar in the bloodstream.

Low-GI foods include peanuts, pasta, red wine and muesli and have a GI index of 55 or below.

These are foods whose carbohydrates are slowly broken down into glucose by the body and absorbed into the blood, meaning the blood sugar level rises and falls more gently.

The slower glucose is released into the blood, the longer our energy levels are sustained.

High-GI foods - such as beer, white bread, white rice and sugary cereals - are those with mainly refined carbohydrates and have a rating of 70 or above.

They release large amounts of glucose quickly, causing a rapid rush in blood sugar levels, followed by a rapid drop.

The diet works on the principle that eating low-GI foods helps people to stay feeling full for longer and prevents snacking. Low-GI foods also tend to contain fewer calories in the first place.

Dr Toni Steer, from the Medical Research Council's Human Nutritional Research laboratory in Cambridge, said research into GI foods was still in its early stages.

'Blood sugar levels are believed to be one of the controllers of hunger,' she said. 'This diet has the potential to work because low-GI foods give a gentle rise of blood sugar levels, helping us to feel full for longer.

'And because they also tend to be high-fibre foods, such as wholemeal bread or brown rice, their bulky nature makes us feel full too.

'I can see this diet being particularly helpful, not just in aiding weight loss, but in helping to keep that weight off - something most other diets fail to address.'

The diet also recommends eating most fruits, oils and protein such as chicken breast, which all release sugar into the bloodstream slowly.

But there are wild variations. A banana has a high- GI rating, whereas raspberries and blueberries have low ratings.

Earlier this month, an Oxford Brooks University study found that children who ate high-GI breakfast cereal such as Cornflakes, Rice Krispies or Sugar Puffs became hungrier earlier than those given low-GI, highfibre alternatives which contained slow-release sugars.

Children on the low-GI breakfast also ate more moderately for the rest of the day.

The GI index was first devised over 20 years ago to help diabetics control blood sugar levels.

In recent years, nutritionists have started to look at the possible benefits on diet in general.

The GI diet could also help sufferers of Syndrome X, such as chef Antony Worrall Thompson.

The little-recognised, pre-diabetic condition leaves sufferers feeling lethargic and has been described as the 'new ME'.

It strikes when blood cells become overrun with sugars and can no longer burn off enough of that sugar, so it is stored as fat instead. Low- GI foods provide the body with the nutrients it needs to burn sugar effectively.

A string of books advocating the GI route are starting to dent the bestseller lists and Mr Worrall Thompson has co-written one such book, aimed primarily at diabetics.

He said: 'I've lost one stone and two pounds since I modified what I was eating. I feel so much better for it.'

A British Dietetic Association spokesman said: 'The basic principle of eating low- GI food is good because they do tend to be those sorts of foods that are high in fibre.

'But people shouldn't become obsessed with it. Even if they eat low-GI foods they will still put on weight if they fail to burn off the calories they have consumed.'