LONDON — Obese women have four times as many unplanned pregnancies as healthy-weight women despite having less sex, and obese men are more likely to have sexual diseases despite fewer partners, scientists said on Wednesday.

In a study showing how obesity can harm sexual health, French and British researchers also found that obese women are less likely to ask for contraceptive advice or use the pill, and obese men are more likely to suffer from erectile dysfunction.

With obesity epidemics overwhelming many wealthy nations and threatening increasing numbers of developing countries, experts said the public health impact of the findings was important.

In the United States, for example, two-thirds of adults are overweight or obese.

‘In public health terms, the study lends a new slant to a familiar message: that obesity can harm not only health and longevity, but your sex life,’ Sandy Goldbeck-Wood, a specialist in psychosexual medicine at Britain’s Ipswich Hospital, wrote in an editorial on the study in the British Medical Journal (BMJ).

The research, led by Professor Nathalie Bajos of France’s National Institute for Health and Medical Research (INSERM), is the first major study to investigate the impact of being overweight or obese on sexual activity and other factors such as […]