Space Case. The photographer said that Yoanna's body needed work meaning to tone it up. I think that he meant more muscle definition, especially in the stomach where (after losing a lot of weight) the muscles get fatigued quickly. Most models need lots of gym work for all the posing they do, especially in their stomachs.
Of course, they went to a gym in episode 2 and Yoanna stated that she never exercised. i definately don't think it was meant as to gain or lose weight.