so, here's your interesting fact for the day:

alcohol itself increases insulin response to sugars
i recall there is also some insulin related effects with THC as well, the well known munchies are caused by a spike of insulin, and this effect diminishes very quickly with frequent smoking
more facts coming to hand that explain the biological basis of some mostly bad habits
still gotta be careful but paying attention to the sugar factor first then maybe other things can be more precisely weighed up