For many people it’s extremely difficult to stick to a strict diet for more than a few weeks.
Prof Byrne said having breaks from strict regime 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 continuous.
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.