Researchers from the University of Kansas School of Medicine have been looking into the relationship between body composition (how much of our body is fat and how much is muscle, bones and organs) and Alzheimer's disease. Weight loss often happens among people with Alzheimer's disease and can occur before any symptoms of memory loss. The researchers studied 140 people aged 60 and over, half of whom had Alzheimer's disease. The participants also had MRI brain scans and psychological tests. The study found that lean mass was reduced in the people with Alzheimer's disease. Decreases in the volume of the whole brain and of white matter, and declines in cognitive performance were all associated with loss of lean mass but it was a decline in lean mass, not an increase in body fat that was responsible for people's changing body composition. It is not known whether the loss of lean mass is associated with the lack of exercise on the part of people with Alzheimer's or whether there is some underlying mechanism responsible for a loss of lean mass and Alzheimer's disease.