Washington: It may be quite a struggle, but most of us do manage to lose weight - but keeping it off is another matter. So now an ongoing study has set out to identify the most effective diet to help adults stop regaining weight after initial loss.

As part of the study, adult family members were required to lose at least eight percent of their body weight, before the whole family was allowed to enrol in a 'dietary intervention' programme involving one of five diets.

About 760 participants were successful, losing between them a total of 8,500 kg, equivalent to the weight of four fully-grown bull elephants and 11.2 kg on average for each person.

After this successful weight loss phase, 565 families (763 adults and 787 children) were randomly chosen to follow a diet either high or low in protein or high or low in the glycaemic index (ranking carbohydrate foods according to their effect on blood glucose.) The fifth diet, the control diet, was based on the family's usual diet but with additional advice on the inclusion of healthy foods.

In Copenhagen and Maastricht centres, supermarkets set up for the study provided families with free food for six months, followed by six months of dietary advice and support. The other six centres (Britain, Bulgaria, Crete, Czech Republic, Germany and Spain) provided families with six months of dietary advice and support only.

'The real target in this research study is the prevention of weight regain after initial weight loss,' said Arne Astrup of the University of Copenhagen and coordinator of the eight-country study. 'Most of us can lose weight if we set our minds to it - but we are not so good at keeping it off.'

Preliminary results from study will be unveiled at the forthcoming European Congress of Obesity. IANS