If you have Parenthood you can send your Sim to work/school with a sack lunch (you can make a sandwich or even just pack leftovers from last night's meal) -- if your Sim is hungry enough they'll eat it and get a "Packed with Love" happy moodlet which can help boost whatever moodlet is required for good work/school performance. If you have a Sim with the Fresh Chef trait (from one of the Cooking aspirations), put them in charge of all meal preparation and lunch packing because the food they make never spoils. I've also seen low bladder miraculously get solved so I assume they get to take bathroom breaks as well.
