This happens to me too, especially in settings other than my own home. I've recently lost 25 lbs. I think part of it is due to fat loss and the body adjusting to that. I've noticed sometimes my nose runs after I eat then too, perhaps because im cold? Not sure. Anyway, it happens to me all the time and I dont think much of it. Its also accelerated because your bodys energy is diverted into digesting your food, and less on keeping you warm for the time being.