SYDNEY, Sept. 16 -- Losing musce mass as people age could be an important warning sign for dementia risk, new Australian-led research has found.

Researchers analyzed more than 80 studies examining links between body weight, body fat, muscle health and dementia, finding that people with sarcopenia had a 42 percent higher risk of dementia, according to a statement released Wednesday by Australia's Curtin University.

Sarcopenia is a condition where people lose a greater amount of muscle mass, strength and physical function, often as they get older, according to the study published in the International Journal of Food Sciences and Nutrition.

The study also found that the relationship between obesity and dementia depends on age: People with...