Is the underlying concept related to 'By analyzing proteins in the blood, one can estimate a person's biological age, as well as weight, height, and hip circumference, mentioned in this article ?
The two concepts definitely may be related, but the approach used in this paper doesn't make use of proteins in the blood. Rather it uses the DNA methylation extracted from white blood cells in the blood.
https://www.dailymail.co.uk/sciencetech/article-3349739/Woul...