Aside from providing a new excuse for a widening girth, what does the finding mean? Even Dahners was hard-pressed to come up with anything important to the practice of treating patients with bone problems. "Does it make us fix broken bones differently now? Does it make us put in our special joints differently?" The answer was a resounding no.
"Basically, I just thought this [widening] was interesting to know, but I really don't know where it's going," said Dr. Elton Strauss, an associate professor of orthopedic surgery and geriatrics at the Mount Sinai School of Medicine in New York. "I think this is something that maybe is going to come to light 15 years from now, as they get autopsy specimens or other studies that look inside the bone to give some kind of idea of what the issues are. They really can't come up with a reason as to why the pelvis widens."
Dr. Clifford B. Jones, a clinical professor of orthopedics at Michigan State University, said the widening could come from muscle stress. "You've got muscle attachments to the pelvis, and they all want to pull. That could relatively widen your pelvis due to the fact that your pelvis brim area is going to get wider and wider from these muscles pulling off and stressing." Or maybe it's estrogen. "Men have female hormones, too, to a lesser degree, and that could be causing it," said Jones. "Or it can just be more maturation that you have over the years."
Despite the ambiguity about its cause and implications, a spreading pelvis does not offer a Get Out of Jail Free pass for packing on pounds. "We can say their bones are getting wider, and that's the reason they look wider," Dahners said. "We can't say you're not getting fat, because you might be getting fat, too."
As an explanation for the obesity epidemic, "this [widening] phenomenon explains exactly none of it," said Dr. David Katz, director of the Prevention Research Center at Yale University School of Medicine. "Whatever accounts for these skeletal changes, there is certainly no reason to think it … has occurred only in the last few decades. Presumably, skeletons have always behaved this way, yet epidemic obesity, at ever younger ages, is a new phenomenon. An old cause cannot be used to explain a new effect."
And that's little consolation for most of us.