Pelvic widening continues throughout life

The pelvis continues to grow wider even after people stop growing taller. This increase in pelvic width may account for a significant portion of the weight gain that many people experience as they get older. By the age of 20, most people have reached skeletal maturity and do not grow any taller. But the pelvis (“hipbones”) continues to widen as people advance in age from 20 years to 79 years.

Read more at University of North Carolina