Losing weight is not only good for your heart, it can also improve your sex life, says a new US study.

Martin Binks, a psychologist at Duke University, said while other studies have found that overall quality of life improves with weight loss, little research had been done addressing sexual quality of life.

In their study, Binks and his colleagues examined data on 187 obese dieters who attended a weight-loss programme at a medical centre in Minnesota several years ago, the online edition of USA Today reported.

The participants were mostly women who weighed an average of 248 pounds.

The research showed that dieters who lost about 13 percent of their body weight over two years felt more sexually attractive, had greater sexual desire and reported other improvements in their sex lives.

The participants followed a weight-loss programme that included dietary counselling and prescription weight-loss medications for two years, it said.

At the end of the first three months, dieters lost an average of 12 percent of their starting weight and reported improvements in all areas of sexual quality of life.

The biggest improvements were in sexual attractiveness, willingness to be seen undressed and sexual desire.

Before weight loss, about two-thirds of participants reported feeling sexually unattractive at least "sometimes." Those who were the heaviest were the most likely to report feeling sexually unattractive.

Every three months for two years, the dieters were weighed and filled out a questionnaire that evaluated their sexual quality of life, including feelings of sexual unattractiveness, lack of sexual desire, reluctance to be seen undressed, difficulty in sexual performance, avoidance of sexual encounters and lack of enjoyment of sexual activity.