On the Mayo Clinic Radio program, Dr. Donald Hensrud, director of the Mayo Clinic Healthy Living Program, discusses the obesity epidemic and talks about popular diet trends, including intermittent fasting. Also on the program to recognize Feb. 14 is National Donor Day is Dr. Mikel Prieto, a Mayo Clinic transplant surgeon. Dr. Prieto explains living kidney donation. And Dr. Susan Cullinan, a Mayo Clinic emergency medicine physician, shares tips for avoiding winter safety hazards such as carbon monoxide poisoning, frostbite, and winter falls.