Not sure if youa re serious... Couple weeks shouldnt do anything. Most likely you are not eating enough in those weeks, and your body will slim down due to all that extra food and liquids in your body exiting during that time. So not necessarly muscle loss, rather a lot of factors such as water, food, fat etc.
Like you can look bloated when you eat a whole lot for awhile, or even a whole day, does it actually mean you got fatter/bigger and gained all that weight? Nope in a few days you'll be back to normal if your diet goes back to normal.
Even when you do lose muscle, your body will gain it back a whole lot quicker once you get back at it due to muscle memory. (I am in know way an expert, only been lifting for over a year, but throughout my findings from people and online, this is some of the stuff I have remembered)