I dont get all this cook your own food, bring sandwiches/flask etc to work every day. I've tried it all and it just doesn't pay. You still stop for lunch whether you eat your own sandwiches or go to a shop and eat them so there isn't any time saved, usually you call in at a shop on the way to the wholesalers so its not even a special journey. Yes it saves money and with todays prices you could probably save £5 a day making them but it took me about 15 minutes every morning to make the sandwiches, fill a flask etc. It was such a waste of time that I would have gladly paid someone that £5 to make them for me.
And the amount of times that I came home with a full flask because I was too busy in the day to drink it meant that it either went down the drain or I had 4 cups of coffee in the evening and was then wide awake all night, total waste of time in my opinion.