You mean you want to be able to pay for meals with your student card right?
You should sign up for an off-campus meal plan. See details here (
http://hospitality.mcmaster.  ca/mea...offcampus.html ). 
If you don't want to commit to spending a certain amount in a certain period of time, I would recommend purchasing the 
Freedom Plan, as it is very flexible and you can refund at any time, even though you must initially deposit in $100.