There's no easy way to get slim

Dieters looking for tricks to lose weight got more bad news this week with the publication of a university study showing diets that restrict certain food groups do not take any extra weight off.

But adding whole grains may help, another study shows.

A study of 80 overweight or obese people shows they all lost the same amount of weight regardless of whether they were on an extra low-fat diet or one targeted at the so-called glycaemic index, which aims to cut foods that affect insulin.

"Despite all the controversy about diet ... a calorie is a calorie is a calorie," said Ernst Schaefer, of Tufts University in Boston, who led the study.

"No matter how you lose weight, you lose the same amount of weight," added Robert Eckel of the University of Colorado Health Sciences Centre and president-elect of the American Heart Association.

The association has stuck with its recommendations that weight loss requires a boring but effective approach - eating less, exercising more, and basing the diet on vegetables, fruits, whole grains and little fat or meat. But it regularly supports research aimed at seeing if there may indeed be quicker ways to weight loss, because losing weight is known as one of the best ways to prevent heart disease.

Schaefer told a meeting of the association in New Orleans that he put his 80 volunteers, with an average age of 54, on various carefully controlled diets for three months.

One diet got 15 per cent of calories from fat, another was closer to the US average, with 30 per cent of calories from fat, and another had a low glycaemic index.

All the dieters cut their usual intake by about a third, but they could ask for snacks.

After the first three months they were told to stay on their diets but were not watched so carefully. Their progress was followed for a year.

All the dieters lost 6 per cent to 8 per cent of body weight, and all improved their cholesterol levels, Schaefer said.

"The average weight loss was 7kg to 8kg," he said.

But the low-glycaemic diet was harder to follow, he said.

"People have to really track what they are eating."

The theory behind diets to control glycaemic index is that some foods affect the ability to process sugar more than others.

White bread and processed sugar have a high glycaemic index, while whole grains have a low one.

"For weight, exercise and calories are critical but for heart disease I believe animal fat and sugar are the culprits," Schaefer added.

A second study, published this week in the American Journal of Clinical Nutrition, shows that people who added whole grains such as whole oats and whole-wheat bread to their diets lost more weight.

Pauline Koh-Banerjee and colleagues from the University of Tennessee and the Harvard School of Public Health studied 27,000 men and found the more whole grains they ate, the more weight they lost while dieting.

They said fibre in the diet might fill people up faster than processed grains and perhaps by helping to regulate blood sugar levels.

"Moreover, because of their high fibre and water content, whole-grain foods contain fewer calories gram-for-gram than does [the same] amount of corresponding refined-grain food," they wrote.

- REUTERS