Good points, Serenity. Having a balanced meal several times a day both keeps your blood sugar leveled and adds some rhythm and continuity into your day.
Another thing against stress is a hobby which demands all of your concentration while you're at it. I'm on my second winter building electric guitars at the community college and I must say it's addictive! Starting from planning, choosing the wood, sawing the rough lines, planing, thicknessing, routing the cavities, carving the neck and body to your liking, fretting, sanding through grits until the wood is smooth as silk, oiling/waxing/lacquering, sanding again in between the layers, oiling/waxing/lacquering again, fitting the hardware and strings for the feel, detaching the hardware, modifying if needed, sanding through the finest grits, polishing, fitting the hardware again, adding the electrickery and finally plugging into an amp for the first time. Plus chatting with the other people there, admiring their projects and getting yours admired.
Of course it can be anything as long as you have to pay attention to what you're doing so that you simply can't think about the things that give you stress.