I don't take weeks off. In most of the last decade, if I am away from the gym more than four days, it is either because of a hurricane, being in a country with no gyms, or in the process of finding one close by. Unless you just went through the stress of getting into competition shape, your training shouldn't be leaving you so incapable of recovery that you need to take weeks off.
Beyond that, my diet doesn't change depending on what my goal is. Even if I was away for 4 days or so, my usual course of action is to train even harder right before I leave so that the days off are justified as far as recovery.