Conducted by researchers from the University of Melbourne on 204 obese men and women divided into two groups, an Australian study found that those who followed a diet fast as those observing a slower regime had ultimately the same chance to resume bulk of the weight lost.

The first group followed a very restrictive diet -450 to 800 calories per day- for 12 weeks, while the latter reduced its energy intake by 500 calories per day for a period of 36 weeks, says the study published Thursday in the The Lancet medical journal Diabetes and Endocrinology.

Those who, after the regime had lost 12.5% or more of their weight were then subjected to a steady state for three years.

At the end of the experiment, people in both groups had gained a little over 70% of lost pounds. "Our data should encourage committees that develop clinical guidelines for the management of obesity to modify their advice," the researchers said.

It is usually recommended for people who are dieting to lose no more than 500g a week.

However, the study noted some short-term differences between the two groups: 81% of those following a very restrictive diet have achieved their goal of weight loss against only half of the other group. Those in the first group were also less likely to abandon their plan along the way.