Here’s a quick guide to some of the factors that affect your frame.
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When it comes to protecting your body’s 206 bones, it’s never too early to start, says Abby Abelson, MD, chair of the Department of Rheumatic and Immunologic Diseases at the Cleveland Clinic. “Many women don’t even think about their bones until they reach perimenopause,” she explains. “But there’s plenty that women can do in their 30s and 40s.”

And that’s key because, as we get older, we become particularly vulnerable to problems like osteoporosis and stress fractures, thanks in part to changing hormones. Here's what affects the strength and overall health of your bones, both now and as you age:

The Slowdown of New Bone

By the time you’re 22, you’ve developed up to 90% of your bone mass. Your body still adds it until about age 30, “just at a slower rate,” explains Abelson. Then you maintain an even bone mass until you reach menopause. After that, estrogen levels drop and old bone is taken away faster than new bone is built. That’s why postmenopausal women are more susceptible to osteopenia (or bone thinning, the early stage of osteoporosis) and why it’s so important to commit to healthy bone habits, such as getting enough exercise.

The macro diet is designed to feed your body an ideal diet to make it operate more efficiently:

The Role of Belly Fat

For years, it was thought that a little extra padding helped reduce the risk of osteoporosis. But more recent research suggests the opposite, especially if your fat is concentrated in your middle. Harvard researchers found that premenopausal women who had more visceral fat also had decreased bone mineral density.

One theory posits that overweight people are more prone to vitamin D deficiency, since the fat-soluble vitamin can get trapped in fat tissue, says Abelson (Here's how to prep mushrooms for maximum vitamin D). Other research has shown that people with high levels of fat in their liver, muscles, and blood have more fat in their bone marrow, which can up the risk of fracture.

Incredible Shrinking You

It’s not uncommon for women to get a bit shorter as they age. “The disks between the vertebrae in the spine become dehydrated and compressed,” explains Mone Zaidi, MD, director of the Mount Sinai Bone Program in New York City. Your spine also can become more curved as you age. If shrinkage happens gradually over three or four decades, there’s no need to worry. “But if you suddenly lose an inch and a half in height, you should be concerned,” he says. “It could be due to a vertebral fracture and can indicate osteoporosis.” While contracting slightly is natural, you may be able to minimize height loss by sticking with your workout routine: One study found that people who stayed active shrank less than those who were sedentary or stopped exercising in middle age.