While one in seven of women in Britain can stick with a diet for 13 weeks or more, nearly one in four succumb to their favourite food cravings after four weeks.
The poll of 1,000 women's dietary habits was commissioned by Splenda Sugar Alternative as part of the Small Steps campaign, which aims to provide people with series of recipes and healthy living small steps in partnership with TV chef and healthy eating guru Nadia Sawalha.
The research found that the average age for a first diet is 26 years, but one in three women started a slimming regime between the ages of 15 and 20. A typical British woman will go on a diet 2.7 times a year, but more than one in ten will slim for up to five times in a year.
Women said the most popular reason for losing weight was being shocked at seeing themselves in a photograph or catching a glimpse of themselves in a shop window, the research also revealed a number of bizarre factors which prompt diets.
A spokesperson for Splenda, Maria Somalya, said: "We know that going on a diet can be a challenge for many women. However, the real test of a diet is not just losing a few pounds quickly, but taking small steps in your lifestyle that last for years and can make a big difference such as switching from sugar to Splenda.”
Some women admitted they embarked on a diet after being asked if they were pregnant, others when they suspected their partner was having an affair or their sex life had dwindled. Others decided to reduce their weight to get back on to the dating scene after a break-up or after realising they were the fattest person in their office.
Six in ten women said food cravings make diets difficult, followed by 'simply loving food' and feeling depressed.
Other factors which make diets difficult include cooking and shopping for the rest of the family, going out to dinner and slimming on your own. In fact, weight loss is most likely to be derailed by dieters themselves, partners and female friends.
Food craving also make it difficult to stay on track whilst dieting, the hardest things to resist are chocolate, crisps, cheese, bread and wine. Followed closely by biscuits, cakes, sweets and Indian and Chinese meals.
When it comes to strange things people have done in order to stick to a diet, women admit they have eaten in the garden shed away from their family, eaten food that was going off to lose their appetite, bought clothes which were too small, padlocked cupboard doors and even gone to bed early.
Strangest things which prompt women to lose weight: