I'm not sure that unis really have just a 'cafeteria' as such. My undergraduate campus had a refectory (your basic cafeteria food), pasta bar, pizza place, sandwich bar, coffee bar, supermarket (with baguette/sandwich service), tuck shop (with hot panninis, pastries, crisps (potato chips), chocolate, candy etc.), a pub (with meals sold there), a sit-down restaurant and a pizza/burger take-out place, and then dining halls in each residence hall for people living on campus.
I don't think there are such things as 'meal plans' in the UK (I'd never heard of them until I moved to the US and I already had 2 UK degrees). If you live in catered accommodation on campus, you eat whatever the university provides for you in their dining hall (there is usually a choice of 2 or 3 meals and meal costs are usually included in the rent - I had 21 meals per week included in my rent, plus vouchers to use almost anywhere on campus for lunches in the week) and if you live in a self-catered apartment or house, you generally cook everything yourself or eat out on campus. I've found that most people who live off campus either go home to eat lunch, bring food from home or pop down to the supermarket for a salad or sandwich.