How true is the albeit exaggerated statement that men will sleep with anything?

Back when I was single and engaging in hookup culture it was easy to hook up with guys who were more attractive than me. I'll be real I'm a fat girl (working on it but whatever), why would fit hot guys who work hard on their bodies want to sleep with someone who doesn't? Just because it's easy? Even though they could get a hot girl with a good body? I know it's just sex but ?

Also, because average and even below average women can sleep with attractive guys and they do, then who sleeps with average and below average guys?