Relation of fat mass and muscle mass to risk of all cause mortality

The Study

Subjects from 7 different prospective cohort studies had their body composition measured and were followed for an average of 14 years. Over 16,000 subjects were included in this investigation.

Here is what the researchers found:

-When compared to subjects with the lowest body fat, those with the highest body fat had a 56% increased risk of dying from any cause.

-When compared to subjects with the least muscle mass, those with the highest muscle mass had a 30% lower risk of dying from any cause.

-The BMI of the subjects correlated extremely well with their body fat (r = .813).

-The BMI of the subjects also correlated very well with their muscle mass (r = .710).

American Journal of Clinical Nutrition 2021; 113:639-46.  

Take Home Message

This study shows us the importance of not only maintaining a healthy weight, but of preserving our lean body mass. We start to lose muscle after the age of 25. If we don’t actively work on maintaining our muscle, this loss can have a seriously negative impact on our health and ability to function as we age. Hit the weights at least twice per week to prevent the loss and even add to your lean body mass. 

One other interesting note from this study: body mass index was highly correlated with both body fat and lean body mass in this large population. There are many who think it is not an important measure. This study shows that it truly is.