Short answer: no.
Some folks are worried that if they start medical cannabis, they will get the munchies and put on weight. This almost never happens (we have seen over 3000 people, and only a handful have reported weight gain).
Wait. I'm going to LOSE weight?
Yes, most likely. It works like this: you are putting on weight because you are not moving enough due to pain, and you are feeling stressed due to pain. So you increase your stress and decrease your activity and what are you going to do? Exactly: get some pleasure out of food.
When you get your medical cannabis tuned properly (see us), you will have less pain so you can get walking and moving around more. Less pain plus more activity means less stress in your life so less need for the food to substitute for the pleasure you get just living your life.
The amount of THC and CBD that most folks need to get these benefits is way less than the amount stoners use to get their buzz, so there is just less cannabis around to give you the munchies when you use it medically.
Less pain? More activity? More pleasure out of life? Losing weight? Sounds good to me.