I pack my clothes, lunch and laptop in a Chrome messenger bag on my back. I have a huge storage ziploc bag of oatmeal at work and a bag of coffee grounds (I bring these in about once a month or so, its my heavy bag day ). When I bike in, I make a green drink w/ice and put it in my polar bottle then bottle cage. On my back, for food, I bring a small bag of almonds, cottage cheese in a frozen tupperware cup, greek yogurt plain, apple and a banana. I just snack all day on those items and drink my green stuff around noon.