I lift weights 3 times a week and take my dog on lots of walks everyday. I always gain weight around the holidays though. I dont have the self control I need around cookies and eggnog and all the other seasonal junk food. If you dont have the time to exercise I'd just try really hard to eat healthier things when you're high. Keep a bag of baby carrots in the house instead of chips. Drink water instead of soda. It's not fun, but neither is feeling bad about yourself. I also think its really fun to take a walk while you're high and its snowing outside. Night time walks while you're high in general is amazing.