Yes, while it might seem odd that an overweight person would have this condition, it is possible for an overweight person to be anorexic. Ultimately, an overweight person only need suffer from the three conditions (body dysmorphia, a fear of gaining weight, and a fear of food) for them to be considered an anorexic.
In fact, many overweight people who severely reduce the amount of food they take in to lose weight can develop the same symptoms, as their digestive, endocrine, and pulmonary systems become stressed as a result of severely reducing their food intake on a daily basis.
Moreover, many overweight people assume that to lose weight that they have to dramatically reduce their food intake, and so it causes them to eat one big meal a day while starving the rest of the day.
However, whenever unhealthy diet habits create a cycle where the body moves into starvation mode, the overweight person experiences the opposite effect because the body, in an attempt to hold onto fat, makes it difficult for them to lose weight. In essence, they suffer from the same physical ailments that skinny anorexics do, but they just carry more weight.