Try to get into a decent sleeping schedule because rest is really important even if we do kid around about it being a waste of time.
Besides that, even if you are a webmaster and work from home there is no exceuse to be eating junk food every day and sitting behind the PC drinking coffee, soda, or beer for most the day. Have normal, good healthy meals, not even healthy, just vary your diet with regular food and avoid the fast food stuff.
If you find yourself drinking alot during the day, especially bad shit, it's probably to keep you awake because you arent getting enough rest to begin with which is the real problem.
Besides that take a break every few hours and try to get a bit of excersize during the week and you should be all set.
Summary: getting proper sleep is most important