Her contract will have set out what she will and won't do which will no doubt include volume/type of food to be provided. She left the jungle after a couple of days because she was so hungry so seems likely she won't have wanted to do anything 'healfy'.
One of the few reality types to have lost a few lbs on the show, which proves she can do it, but does not have what ever it takes to make the obligatory fitness video. Look what Josie did!