A recent study conducted by researchers at John Hopkins looked at how obesity in midlife affected prevalence of kidney disease later in life. The researchers specifically looked at race and age as factors in addition to obesity.
The results were that Black and white women and Black men who were obese during midlife showed an increase risk of end-stage kidney cancer later in life. This correlation was not seen in white men in this research.
The research shows that combatting obesity can be useful in kidney health, therefore decreasing the risk of kidney disease. As with other weight related health concerns, where fat is located may be just as much or more of a predictor than BMI alone. Waist-to-hip ratio, which looks at visceral fat (or, belly fat) may be an even more important predictor of weight-related health concerns.
Visceral fat is already known to be linked to higher risks of heart disease, some cancers, and diabetes, and is the fat that is founds around your abdominal organs. Because visceral fat is found inside the abdomen, it is difficult to measure without scanning, but BMI and waist size can be good starting points in consideration of visceral fat. BMI of over 30 is considered overweight, and waist measurements of over 35 inches in women and 40 inches in men can be an indication of visceral fat.
The John Hopkins study linking obesity and kidney disease followed participants for 30 years, and included over 13,000 people. According to the researchers, more research needs to be done to see why some demographics have a higher correlation between obesity and kidney disease than others.