they havent been there that long and they ave access to food
if anything lack of food would increase his weight at first anyway
as if you dont eat a regulary your body will store a majority of any food you do eat as fat to save for a later time as it does not no when thenext meal will be coming.so ur metabolisim slows down
this is 1 of the reasons u shouldn't skip breakfast!!
that solved it for u ?