Revenge of the fat lollers

I like to think I'm a fairly stoic Londoner; I take the rough with the smooth, and generally have decided that the benefits outweigh the drawbacks.  However, this last week has been particularly horrendous as far as commuting goes, with delays in either one or both directions on the daily work journey, with a grand finale on Friday. It took me a grand two and a half hours to get to work, including a delightful half-hour spent hemmed in at Bank Station, unable to exit or move left or right, owing to massive volumes of people.  Bank Station isn't even on my route to work.  Fuckers.

I have a sneaking suspicion that the staff on the Jubilee Line are intentionally fucking up the service, in reaction to job cuts.  You heard it here first.

On the way home on Friday, I'd had enough.  And whilst the transport that evening was running normally (probably because most of the usual commuters had committed suicide on their journey into work that day... knowing my luck, by throwing themselves under the nearest Central Line train), I still managed to have an irritating commute.  I was sat next to a fat loller.  See here for my thoughts on fat lollers from a few years ago.

This one was not a bus loller, but a tube loller.  He lolled to the extent that his head lolled past my shoulders and towards my chest.  He eventually lolled so much that I wondered if he was actually attempting to breast feed.  I poked him with the pointy corner of my work bag.  He didn't wake up.  I poked him again, harder.  He continued to sleep.  I elbowed him in the head.  He still didn't wake up.

It was at this point I realised he was dead.

No, of course he wasn't.  But wouldn't that have been awful  And also a little bit funny?  Oh.  Never mind.

But question: why do fat people fall asleep / loll more than thin people?