The prevalence of obesity has risen dramatically in the last few decades, affecting more than one in three adults in the United States. Presence of class II and III obesity [body mass index (BMI) >=35 kg/m2] is associated with a greater than six-fold increased risk for end-stage renal disease. We and others have shown that reductions in weight are associated with decreased urine protein, which is a marker of kidney damage. However, there is little data on long-term effects of weight loss on kidney function. At Geisinger, one in five primary care patients has a BMI >= 35 kg/m2, and over 300 patients undergo bariatric surgery each year. We are conducting retrospective studies to examine the effect of bariatric surgery-induced weight loss and kidney function. Future study includes conducting a prospective study to investigate the effect of bariatric surgery on measured kidney function. Through funding from the National Institutes of Health, we are conducting studies to determine the long-term effects of bariatric surgery on kidney function. Future goals will be to test remote dietary counseling strategies in patients with kidney disease.