I think the food expense is pretty high too. At the very least get a brita filter or something and carry around bottled water to drink. Some people do eat a lot more though.

And it's worth noting that cooking for yourself doesn't always save time. After you consider preparation and cleanup, sometimes it consumes more.

It can also be stressful if you don't have a nice kitchen, or if you have to share your kitchen with others. Although probably one of the benefits of having founders living together is optimizing your kitchen.