Dieters in the US study reduced their risk of heart disease by between 5 and 15 per cent. Picture / Nicola Topping

Dieters in the US study reduced their risk of heart disease by between 5 and 15 per cent. Picture / Nicola Topping

By MAGGIE FOX in Orlando

No matter what diet you are on, if you eat less and lose weight you lower your risk of heart disease, researchers say.

Weight Watchers, the high-fat Atkins diet, the extremely low-fat Ornish diet and the high-protein, moderate carbohydrate Zone diet all helped people to lose weight and all reduced cholesterol, but in different ways, the American Heart Association heard yesterday.

Dr Michael Dansinger, of Tufts University, Boston, said: "On average, participants in the study reduced their heart disease risk by 5 per cent to 15 per cent.

"Instead of saying there is one clear winner here, we are saying they are all winners."

As might be expected, the closer dieters followed the plans, the more weight they lost.

Those who stuck it out for a full year lost, on average, 5 per cent of their bodyweight - or about 4.5 to 5.5kg.

While the dieters reduced heart disease "risk factors" such as cholesterol levels, overall blood pressure did not drop much and the study did not last long enough to see if this translated into a lower long-term risk of heart disease.

Instead, the researchers used statistics that show lowering cholesterol by a certain amount, for instance, reduces the risk of heart disease overall.

Dr Robert Eckel, of the University of Colorado, said the message was clear - lose weight however you can to reduce your risk of heart disease.

For the study, Dansinger and colleagues chose 160 overweight people and randomly assigned 40 to each of four different diets. They weighed an average 100kg and needed to lose between 13 and 35kg.

All agreed to follow the diets to the best of their ability for two months, although none was enrolled in the full programmes that Weight Watchers and Dr Dean Ornish advocate. These include exercise, group meetings and food diaries for Weight Watchers and stress reduction for the Ornish diet.

After two months, 22 per cent of the dieters had given up. After a year, 35 per cent had dropped out of Weight Watchers and the Zone diets and 50 per cent quit the Atkins and Ornish plans.

The study suggests there is no one-size-fits-all diet best for everyone.

"The type of person who is going to go for a low-fat, vegetarian diet is not, in my experience, the kind of person who is going to go for a high-meat diet," Dansinger said.