Subway $5 footlong
Eat half for lunch, eat the other half for dinner.
Thats $2.50 per meal (lunch and dinner) which is only $5 a day.
Cant beat that fast food value plus its way healthier than grabbing a burger/taco/etc.
I suggest getting a turkey/ham/chicken breast, no mayo but you can use mustard (dont use honey mustard, has HFC, also stay way from wheat bread suprisingly it has HFC...your better off with the other breads), pile on the vegetables, etc. Omit the chips/soda. Drink water. As for breakfast, just eat good ol oatmeal at home. Its cheap, healthy, and good for you. The real quaker oats old fashioned oat meal...none of that sugary crap oatmeal. Add some fresh fruit if you desire and have some green tea.
*This is what I do myself...yes the lunch meat in Subway has sodium but it needs to be preserved...still light years healthier than taco bell, jack in the box, mcdonalds, etc.