Yes, Janet, Depression can indeed affect one's appetite, choice of diet, and weight. The control of appetite, like the control of mood, is a complex mechanism involving overlapping processes, chemical and hormonal. With depression, some people lose appetite and lose weight ; others gain appetite and gain weight. If you are indeed suffering from a Depression, it would be wise to get an opinion from an accessible shrink, and consider proper treatment for the Depression. And any therapist values a client who follows plans religiously !