Does hypochondriacs lose weight more quickly?

Not specifically...: Being a hypochondriac does not have any specific link to weight. If someone loses their appetite when they are stressed, and they are feeling particularly anxious about their health then they may lose weight. However, someone else might eat when feeling anxious and gain weight. It depends on the person.

No: Hypochondriasis is an excessive preoccupancy or worry about having a serious illness. An individual suffering from hypochondriasis is known as a hypochondriac. Hypochondriacs become unduly alarmed about any physical symptoms they detect, no matter how minor, and are convinced that they have, or are about to be diagnosed with, a serious illness. There is no relation to weight loss that I know of.