Only slightly tongue in cheek, based on being born in Lancashire and moving to Essex when quite young.
So I don't know if it was pure Lancashire, or a mixture.
I do know that in Lancashire it is breakfast dinner and tea whereas in Essex it is breakfast, lunch and dinner.
To me brunch is breakfast eaten so late that is effectively also lunch and a single meal, whereas I am talking above about three separate meals with (small) gaps in between.
I am more serious when I say that I think that it could be related to factory labour which was heavily manual and required a lot of food just to keep going.
I also remember at school having a break mid-morning and mid-afternoon. Still, when you are growing you need more food and I was never over weight as a child or teenager.
I suspect that a lot of T2 may be related to people growing up in a time of manual labour (docks, newspapers, car manufacture, coal mines) which required a lot of food and now being in an age of desk jockeys which doesn't require nearly as much food each day.