At age 14 I obtained a summer job working for a grocery store. Mostly it was mind numbing tedium but having a little money to spend on illegal fireworks was pleasant. I pretty much screwed around and did menial work that older employees were too cool for. Oddly, they were very strict about us taking proper lunch breaks. Possibly they were worried about violating child labor again so we were forced to take an hour lunch break every day. I would have preferred to work straight through and leave an hour earlier but they were not amenable to that idea.
During this hour I would ride my bike over to a local sandwich shop since I did not have enough time to go home for lunch . They sold gigantic subs with a drink for about 10 dollars. It quickly became a midday tradition and my sandwich expenses started piling up. I started to figure out that a large portion of my pay was going right into that sandwich shop each day. At that time I was making $5.15 an hour. After taxes we will call that $4.50 just to make it easier to calculate. After working 25 hours a week I would bring home $112.5 per week. The problem was, I was working 4 days a week which meant taking 4 mandatory lunch breaks at $10 each. That's $40 a week or 36% of my weekly income.
My lunch expense is a slightly smaller portion of my income today but the lesson has always stuck with me. Now I bring my lunch in almost everyday. I have found that the best strategy is to cook up a couple large batches of something you really like on Sunday night and then store it in Tupperware containers. I especially like kielbasa and sauerkraut since it makes my farts quite a bit louder. That way when you are in a rush to get out the door in the morning you have something appealing to grab. Don't worry about napkins, you can wipe your face with all the 100 dollar bills you didn't spend on Taco Bell.