We've all heard of the obesity epidemic and the diabetes epidemic – but what we aren't hearing about is a relatively unknown affliction quietly spreading among our teenage girls. It's called early onset osteoporosis, and, though we've all heard about osteoporosis before, it usually brings to mind post-menopausal loss of bone density, not young women at the height of their physical health. However, new studies show that some women of 25 already have the bone-loss of a 75 year-old! What's going on?

In mature women, osteoporosis is the result of the decreasing estrogen levels as the child-bearing years come to an end. At puberty, it's the increasing estrogen that triggers the body to lay down bone and finish building the skeleton. Women achieve their maximum bone density at about age 20, but the process can only be fully completed if their teenage years are spent actively engaging their muscles, bones, and joints in physical activity.

Girls who play medium- to high-impact sports, bike, dance, tumble, ride, and climb through their teen years are steadily building bone until they hit twenty or so. At this age, bone-growth stops permanently and bone density loss gradually begins. However, girls who fail to regularly exercise run the risk of never building the strong bone structure that will support them through adulthood.

Among my high school students, I've noticed that while over half of them lead fairly active lives, most others are virtually sedentary outside of gym class. While schools require a certain amount of physical activity for each student, there's only so much a P.E. or dance teacher can do to inspire students to move their bodies. So, what's a parent to do?

  • First and foremost, be a good role model. Demonstrate healthy movement yourself with a morning run, evening yoga session, or weekend bike ride.
  • Discuss and compare the exercise value of different activities, such as walking the dog, playing Frisbee, folk dancing, or hiking. How many physical activities does your family do each week.
  • Include your child along as a movement buddy. Long walks and playful adventures are an opportunity for conversation and shared experience, as well as exercise.
  • Encourage children to keep an “activity log,” and talk about it regularly. Aim for 30 minutes a day of physical activity at the minimum.

Although the threat of early-onset osteoporosis is ominous, its danger lies in the fact that few have heard of it, and even fewer know how to prevent it. By educating your daughter about the benefits of physical fitness, you not only avoid this and other health risks, but give her a lifestyle lesson that will keep her healthy for life!