Slimmers can shed more pounds by taking a two-week break from dieting every fortnight, say scientists.
And it boosts their chances of keeping the weight off in the long-term.
Health scientist Professor Nuala Byrne said it combats a phenomenon known as the "famine reaction" - which explains why most diets fail.
For many people it's extremely difficult to stick to a strict diet for more than a few weeks.
But Prof Byrne said having intermittent breaks actually helps - and is the key to lasting success.
She said: "The intermittent group lost more weight and they kept it off for a longer period of time.
"We certainly think part of the reason this diet is working is because of the rest periods."
The study published in the International Journal for Obesity investigated the body's "famine reaction" to continued dieting and its impact on weight loss in 47 obese men.
Two groups of participants aged 30 to 50 were randomly assigned to a 16-week diet which cut calorie intake by one third - 23 of whom maintained the diet continuously.
Take a break
But the others did it for two weeks - then broke from for two weeks eating simply to keep their weight stable.
This cycle was repeated for 30 weeks in total to ensure 16 weeks of dieting. They not only lost more weight - but also gained less after the trial finished.
The intermittent dieters had an average weight loss of 17.6 lbs (8 kg) more - six months later.
Study leader Prof Byrne, of Tasmania University, said dieting altered a series of biological processes in the body which leads to slower weight loss - and possibly weight gain.
Prof Byrne continued to say that researchers in the past had shown as dieting continued weight loss became more difficult.
But this latest study looked more closely at ways to lessen the famine response and improve weight loss success.
The two-week intermittent diet proved to be a more successful means of weight loss compared with continuous dieting, she confirmed.
But other popular diets which included cycles of several days of fasting and feasting were not any more effective than continuous dieting.
These include the fashionable 5:2 diet which severely restricts calorie-intake for two days of the week.