Had a work mate that suffered from this and it was pretty scary, he could fall asleep mid coversation in the canteen (while HE was talking). He got a bollocking from managment for falling asleep during a training course...he was the INSTRUCTOR !
I walked into our site portakabin to find him asleep at his lap-top with about a hundred windows open on the screen as he clicked his mouse each time he woke/fell asleep.
He was often spotted asleep in his car in a layby on his way TO work which (at that time) was a 30 min drive from his home.
I have not seen him for years but he is still alive,now a pilot for Easy Jet (JOKE!!!)
Yes he is overweight but not a heavy drinker.
I hope he is well as he was a nice bloke.
hope this helps
Peteelite
This is a different condition to sleep apnea, which is a breathing problem in overweight people, when they sleep..... 
Narcolepsy is the condition where people often and frequenty fall asleep during the day, during conversations etc.
That's the one, thank you.....
