Diets and exercise that are designed to get you to an ideal body weight are in your best long term interest. There may be some modest changes in your kidney function that may fluctuate from time to time. It is difficult to know if these changes will be permanent or transient. It is best to discuss your concerns with your physician, who is helping to supervise the weight loss program. It is also best to continue to monitor these changes with both blood testing and urine testing looking for changes that may concern your physician. The measurement of estimated glomerular filtration rate (eGFR) is less accurate when these measurements are greater than 60 milliliters per minute per 1.73 meters squared. I suggest you discuss these measurements with your physician.