When I was in my 70's I was startled to find that I had lost more than 2 inches in height on a routine health visit. I scheduled an appt with my husband's brilliant orthopedist, who's a famous spine surgeon in our area. He took an x-ray and smilingly told me I had lost some of the cushioning between my vertebrae. "But don't worry," he said, "you can lose only 4 inches that way, ao at the worst that's all it will be eventually." He was right, and I lost 4 inches - which of course affects your BMI, which isn't fair at all. I'm now a little old lady, though not small.