London, Sep 29 (IANS): Britons are losing out on their sex life, says a survey, revealing that an average British adult has sex only four times a month - less than once a week.

Only one percent said they have sex more than 30 times a month, an average of at least once a day, according to a sex survey by The Observer.

Overall, 63 percent of people surveyed said they were happy with their sex lives - down from 76 percent in the earlier survey done in 2008.

One in seven have had casual sex with someone they met on the internet.

"A total of 22 percent of male respondents - more than a fifth - said they had visited a prostitute. This represents another rise - by four percentage points - since 2008," the survey noted.

It showed that 53 percent of women read erotica while 76 percent of men watch pornography online.

Almost one in five Britons lost their virginity when they were under 16, the legal age of consent in the country, it said.

The survey also found that, on an average, people have had 10 sexual partners, a slight increase from 2008.

The survey appeared in The Observer's "Sex Uncovered 2014" supplement.