Four out of ten women who diet end up heavier than when they started watching their waistline, a study revealed today.
The research also showed that a large percentage of women start noticing the pounds creeping back on just 21 days after reaching their ideal weight.
Yesterday, Dr Ian Campbell of the Jenny Craig weight management programme said: 'In the UK 61.4 per cent of adults are overweight or obese.
'Successful weight management requires a long-term commitment in order to lose weight successfully and for good.
'Dieting can be a real challenge so setting realistic goals and remaining focused on them is important.
'Otherwise as this research shows, women could end up heavier than when they started.'
The 'Food: Body: Mind' report was commissioned by Jenny Craig who quizzed 2000 women aged between 18 and 65 who diet regularly on their attitudes, beliefs and behaviours around weight loss.
Six in ten said they are currently on a diet and one in five women saying they are on a 'continuous diet'.
It found the most common triggers to start dieting was seeing their 'reflection in the mirror', preparing for a summer holiday or unflattering photos posted on social networking sites.
Other popular reasons include comments by friends or relatives or remarks from their other half.
However the study showed that one in ten fall off the wagon within one day, while almost a fifth manage to make it to a week or more. The average is ten days.
Many blamed pressure they put on themselves to lose weight too quickly for the weight gain, which leaves them with a bigger appetite than normal.
Others blamed colleagues, who tuck into fatty lunches and snacks unaware of the effect it has on the dieter, while mothers who polish off their children's leftovers was another common cause of weight gain.
