Whilst on a food related note. A lot of folk seem to have hydration issues cycling, and even on my 19 mile commute would take in fluids. Me, it would just make me need the loo even more than I do; If I ever do any longer distance riding I'm avoiding fluids as much as possible otherwise I'd be spending all my time off the bike.
What I do have an issue with though is food. I get soooo hungry. Which means when I get to work I want to eat all the food I have, but I need to have enough sense and willpower to leave something to eat for before the journey home. The only success I've had here is with packets of porridge. Anything like biscuits, fruit, sandwiches or cereal bars are just too tempting by convenience and I end up eating them. But porridge requires me to get off my arse and go and make it. Fortunately it's not too inconvenient and we've got a microwave and bowls and spoons at work.
The flavoured porridge sachets are great because they taste good with water (more available to me than milk) and only take a couple of minutes in the microwave.
In order of preference:
Dorset Cereals. Tastes as good as it looks. Still looks and tastes great with water because has flavoured oats and bits of fruit in it.
Quaker Oats Oat So Simple. Nice enough. The new Sweet Cinnamon one is lovely. And you can get ones with bits in similar to - although not as fruity as - the Dorset Cereals.
Quaker Oats Paw Ridge. Least favourite as it going along the lines of Ready Brek and is milled finer. For some reason kids are supposed to like it like this. But made with water looks too much like wallpaper paste; tastes fine though.