Tenth of British men 'pay for sex'
More than one in 10 men have paid for sex, according to a major study of British sexual habits.
The majority of the 11% who had done so had visited sex tourism hotspots such as Bangkok and Amsterdam.
The report, in the journal Sexually Transmitted Infections, said paying for sex was linked with other "hedonistic and risky behaviours" including binge drinking and drug use.
It said that young professionals rather than "lonely older men" were paying.
A team at University College London analysed data from the Third National Survey of Sexual Attitudes and Lifestyles.
Their initial study found couples were having less sex than in the 1990s. Now their investigations have turned to the practice of paying for sex.
Just 0.1% of the women aged 16-74 surveyed had paid for sex, but 11% of the men said they had at some point in their lives.
Of the 6,108 men surveyed, 3.6% had paid for sex in the past five years and 1.1% in the past year.
The men who had paid for sex had, on average, more than double the number of sexual partners - 32 compared with 14.
Lead researcher Dr Cath Mercer told the BBC: "I think I was most surprised that it is not paid partners making up most of the total, but they are having more partners generally.
"These men tend to be highly sexually active."
But that comes with a price. The men who had paid for sex in the past five years were twice as likely to be diagnosed with a sexually transmitted infection (STI) such as HIV, syphilis or gonorrhoea.
The most likely age group to have recently paid for sex were those in their late 20s and early 30s.
Other characteristics of those likely to pay for sex included being single, having a managerial or professional job and drug use.
Dr Mercer said the findings broke the stereotype of the "lonely older man" paying for sex.
Nearly two-thirds of them reported paying for sex abroad, with Europe and Asia being major destinations.
"It could be down to opportunistic reasons such as a lads' weekend away, paid-for sex is available, it's something they wouldn't necessarily do at home, but in that situation it happens, but there are other reasons as well," said Dr Mercer.
"What we do in the UK won't stop men paying for sex, we may push them abroad even more."
She said sexual health clinics needed to see paying for sex as a warning sign of other risky behaviour for spreading infections, such as having multiple partners.
Sexual health charity FPA's director of health and wellbeing Natika Halil said: "This study shows that men who have paid for sex are disproportionately affected by STIs, and it's vital we reinforce 'prevention over cure' sexual health messages.
"We heard from many men over the years that had paid for sex abroad and returned to Britain in a panic because they didn't know if they had an STI.
"The best way to avoid this is to keep a supply of condoms with you, and if you do have sex make sure you use them. If you know you have taken a risk, it's important to get tested as soon as possible."