Gamerhelp has a funny list of 11 heinous video game habits:
Becoming a Junk Food Junkie
I know it's easy to heat up a frozen pizza and chomp away while killing monsters, but the last thing you need while neglecting fresh air and exercise is to be weighed down by mama Celeste. This applies to your pets, too. Sparky's life grows shorter with each delicious bite of pepperoni.
Quick Fix: Ask your mom/girlfriend for a little help. You may get slapped, but at least you'll be fed.