How much will you shrink as you age?

I spent much of my teen years slouching and searching for flats to wear. I suppose that’s what happens when you’re five foot nine and all the boys you want to date (and even the ones you don’t) are shorter than you.

Or you’re rejected from the cheerleading team, passed over for the gang of petite, perky girls who can easily maneuver the shoulder stand without fear of tipping over.

Or when you must endure all-too familiar phrases like “How’s the weather up there?” and names like “Tall-glass-of-water” and “Spider Legs.”

And since fashionable flats were hard to find in the late 60s and early 70s, I kept the local shoemaker busy, toting in my heels and shyly asking him to “please cut them down as much as possible.” (True story.)

Alas, time passes, with its way of making you older and a lot wiser. And now I love my height. In fact, I want to hang onto every inch of it.

Because I’m shrinking.

And so are you.

Getting older, getting shorter

“People typically lose almost one-half inch every 10 years after age 40,” explains Andrea Singer, chief medical officer of the National Osteoporosis Foundation.

And if you’re lucky enough to make it to age 70, that loss –  at first gradual – becomes even more rapid. When you add it all up, you may end up one to three inches shorter than where you originally began, she says.

“Height loss is related to aging changes in bone, muscles, and joints,” says a study appearing in JAMA Internal Medicine.

Spinal discs, those gel-like cushions that sit between the vertebrae of your spine, act as shock absorbers to keep your back flexible.

But as the years pass, the discs lose fluid (when we’re born, they contain about 80% water) and succumb to natural wear and tear;  compressing and flattening out. Voila: the spaces between your joints narrow and your trunk and spine shorten.

Most people, by age 60, have some degree of disc degeneration, say experts at Cedars-Sinai Medical Center.

But discs don’t deserve all the blame for a shrinking stature: Muscles matter, too.

Beginning as early as age 30, age-related muscle loss, known as sarcopenia (the loss of skeletal muscle mass and strength), can cost you to lose as much as 3% to 5% of muscle mass each decade, notes the Harvard Health Letter.

In particular, weakened torso muscles – which are responsible for keeping us upright – can cause stooped posture, making you appear shorter.

To keep your core strong for upright posture, steer clear of “traditional” sit-ups, which come at a cost: They can put too much strain on your lower back. Trade them in for exercises like side bridges, planks and abdominal crunches.

Psst….it’s not just your core muscles that can steal inches from your frame; even the flattening arches of your feet (another side effect of age) from degenerating ligaments can bring your height down a (small) notch.

“While a minor degree of height loss is usual and unlikely to be associated with any health problems, significant height loss may indicate osteoporosis,” per the JAMA study.

Osteoporosis, the most common type of bone disease that affects up to 10 million Americans,  ups your risk for broken bones — not only in a hip or wrist, but in your spine, too.

Known as a vertebral or compression fracture, “after several of these breaks, your spine may curve and you may lose height,” notes Singer.

Indeed, compression fractures cause your vertebrae to collapse, rendering you shorter in stature.

While a break in your back may sound painful, most times you won’t feel it, at least not right away. After a while, you may suffer back pain, numbness or tingling, or have trouble walking.

If you notice that your upper back is curving forward or that you lose an inch or more in height in just a year’s time, see your healthcare professional immediately and ask for a bone density test, Singer advises.

It might also be a good idea to also ask for a vertebral fracture assessment, computed tomography (CT), magnetic resonance imaging (MRI scans) or spine x-rays, “which will be able to detect a vertebral fracture.”

Height loss is variable: Some people lose an inch or more in a single decade, some shrink only after age 60 or 70, and a few don’t shrink at all, per the University of California, Berkeley.

Shrinking height = a shrinking ego?

If you lose your height will you lose your edge in life? This question may plague some, especially men, who generally put more of a premium on height than do women.

Though perception does not always equal reality, it can and does influence the way we feel.

Popular consensus demonstrates tall men are seen as leaders with more prestige and better health, while tall women are perceived as being “smarter.”

Though the correlation isn’t entirely clear, one reason could be traced back to human evolution when our environments were physically challenging.

Back in the caveman days, to be a successful leader meant tackling significant physical risks. A fit and imposing figure (read: Tall) was a stronger and more powerful leader than a short one.

But the good news, men, is that while you might shrink, you will shrink less than your female counterparts.

“Men can gradually lose an inch between the ages of 30 to 70, while women can lose about two or more inches over the same time span,” explains Simon. And try telling Winston Churchill, Napoleon or Martin Luther King Jr. — notoriously short men – that they’d never achieve power or status. (How’s that for a dose of reality?)

Once I’m shorter, does that mean I’ll weigh less?

Lost inches in height may cause your BMI, a measure of your body fat based on your height and weight, to shift. And if your BMI goes up, it may throw you into a different category, possibly from “healthy” to “overweight.”

For instance, if you used to be five foot three but are now an even five feet tall, your BMI, which was once 26.6, is now 29.3, inching dangerously close to “obesity” (which begins at a score of 30).

However, this is not necessarily a reason to panic (or go on a diet), since various studies say that a slight increase in BMI – when it’s based solely on shrinkage — doesn’t much matter.

Although BMI is an exact number, some experts say that it’s far from an exact estimate of your degree of “fatness’’ and health risk.

How to stop the shrinkage

You can’t. But there are things you can do to lessen its impact.

“People think exercise can cause disc degeneration, but in fact, safely using the muscles and spine is the best advice to maintain your height,” says Michele Bellatoni, who is the clinical director in the division of geriatric medicine at Johns Hopkins University School of Medicine in Baltimore, Maryland.

Much like a Belgian study that found the positive role exercise can play in slowing height loss, Bellatoni encourages her patients to keep their spine healthy with exercises like brisk walking, swimming (which is wonderful for protecting your joints and allows you to stretch without harming your back and hips), Pilates and yoga.

“Stronger muscles keep the spine upright; good sitting posture helps prevent back pain and strengthen abdominal muscles too,” she adds.

And good nutrition matters, not only for your general health but for the health of your spine, too. The key is getting the right amount of Vitamin D and dietary calcium, says Bellatoni.

The National Osteoporosis Foundation’s recommendations are for women 50 and older to consume 1200 milligrams of calcium each day and get 800 to 1,000 international units (IU) of Vitamin D.

For more on that, see their guide, which includes bone-building foods as well.

At my annual physical this year, I was relieved to learn I’d only lost one inch; I clocked in at five foot, eight inches tall.

The long and the short of it is that I’m still way taller than those petite perky cheerleaders of yesteryear, who are probably evening out at a modest five feet tall — or less.

Who knows, it may be one of them who stops me in the supermarket aisle, asking me to grab those paper towels perched high atop the tallest shelf.

P.S. The weather up here is fine. (Thanks for asking.)