A new study has revealed that four in 10 women in Britain constantly go on a diet in a quest for the perfect shape - but one in six never loses any weight.
Researchers found that the average female goes on three diets a year, each lasting 18 days - or nine-and-a-half years of their life, reports the Daily Express.
But while half shed more than 7lb each time, millions remain the same.
One in 10 stays on a diet for less than five days, three-quarters admit they find it hard to diet and only 10 per cent kept the weight off after dieting.
One in 10 women think about food at least 10 times a day and 40 per cent step on scales daily.
Psychologist Helen Golstein, for diet firm LighterLife, said: "Our research showed that four in 10 women yo-yo diet rather than taking a long-term approach to healthy eating.
"Losing weight can be a real challenge but deciding to strive for it can be life-changing, with physical and emotional benefits.
"If you plan to lose weight then choose a diet that is safe, simple and sustainable and that is right for you."
The study further revealed that being dumped, holidays and too-tight clothes were among the triggers for dieting.