Veteran newsreader says it was a "natural element of sustaining life."
Jon Snow has admitted he thinks about sex every time he meets a woman for the first time and ponders “what could be”.
The Channel 4 News host insisted it was “natural” for men to think of all women as potential sexual partners.
He claimed men were “defined by women”.
“Once you’ve established a friendship or a working relationship with a woman, it’s parked. But it’s an interesting barrier. When you’ve gone through it and arrived at the other side, it’s never a problem again.
“Well I’m not saying it is a problem at all, it’s rather a delicious thing really, ‘what might have been’ or ‘what could be’.”
He labelled it a “natural animal element of sustaining life” but added: ““I’m sure it plays a different role in different men’s personas.”
The 66-year-old, whose wife Precious Lunga is 27 years his junior, disclosed he had a teenage affair with a librarian almost twice his age while studying at Scarborough Tech, despite describing himself as a “slow developer” both academically and with girls.
He said: “I was warned off by my lecturer, who told me I was very unwise to be seen going off in the lunch hour in the librarian’s car.”
Snow was speaking ahead of chairing a discussion about fatherhood at the Being a Men festival in London.
He expressed concerns about “how many men will bother to turn up”, claiming men would rather talk about women than discuss their own sex.
Being a man is “all about women”, he said.
“We are defined by women: they give birth to us and then they define us, although lots try to ignore it.”
The newsreader, who has worked with a string of high profile women including former ITN anchor Julia Somerville, 66, and former Channel 4 reporter Samira Ahmed, 45, who quit in 2011 claiming that bosses had treated her in a sexist manner, admitted he could have done more to support gender equality in the workplace.
He said: “While I aspire to be a feminist, I think I am guilty of just as many failings in terms of supporting women’s equality.
“I couldn’t say I’d really fought for women to enjoy many of the fantastic benefits I’ve enjoyed. In my career I’ve seen plenty of examples of women not given the same opportunities.”
He says many female colleagues had sacrificed careers when they had children while others lost out on children because of their jobs.
Now said: “Television has an undue quantity of women who don’t have children.
“They are less likely to advance someone with children.
“It’s beyond imagination to think that an employer would say, ‘You’re going to have a third child? My dear, it doesn’t matter at all.’
“Men don’t have to face that - ever.”
Snow, who was briefly engaged to fellow ITN journalist Anna Ford, 70, before going on to have two children with former partner Madeleine Colvin, 64, claims his 39-year-old wife has an older “mental age” than him.
He said: “She’s somewhere in her forties. She’s very, very mature. I mean, she’s a serious boffin.’