I think it's because she likes to paint herself as healthier (hahaha) than him. When she have shown their different snack baskets before hers have been filled with raw bars, dark chocolate, chickpea crisps and other "healthy" snacks while his was just regular chocolate and crisps. Also, since she claims that he comes home and "inhales" all the snacks she can proudly say that she has been soo good and not eaten anywhere near the same amount as Phil. She just loooves to mock and put him down for the amounts of food he eats. She can go on pretending being little miss healthy all she wants, we all know that she is secretly stuffing her face with anything she can find.