There's little doubt that dementia wreaks havoc on the mind, but how does it affect the body? Women with dementia begin to lose weight at least a decade before the onset of the first cognitive symptoms, according to a recent study in Neurology. By the time of diagnosis, the sufferers were on average 12 lbs. (5.5 kg) lighter than their symptom-free counterparts. Experts theorize that weight loss may be an early sign of mental confusion, loss of motivation and impaired sense of smell, all of which may reduce a woman's desire to eat.