The researchers acknowledged that their study had limitations. BMI and body fat were measured only once, at the start of the study, and the researchers gathered no data on smoking and physical activity. The study sample was mainly female and white and was restricted to people undergoing bone mineral density testing, which limits how the findings may be generalised.
However, they concluded that keeping body fat low may be more important than maintaining a low body mass index (BMI), and body composition, rather than just weight, should be considered when assessing a patient’s health and risk of death.