Kim Kardashian has shared the results of her full body scan, but what is it anyway?

Kim Kardashian has shared the results of her full body scan, but what is it anyway?

It's not uncommon for Kim Kardashian to give her followers a glimpse into her health and wellness activities on social media. Most recently, the reality TV star and entrepreneur posted her most intimate photo yet: an image of a full body scan.

On Wednesday, Kardashian detailed her experience getting a full-body scan from the company BodySpec on her Instagram Stories, including some snaps of her results. If you have seen the posts on her Instagram, you have seen an x-ray of her body along with numbers and percentages. In her initial posts, she showed off her bone density and body fat percentage and claimed her results landed her in the "athlete category."

Curious about what the purpose of a full body scan is and what Kardashian's results mean? Read on for a breakdown of the health tool.

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What is a full body scan?

Kardashian received a DEXA (dual-energy x-ray absorptiometry) scan, explains Alyssa Olenick, Ph.D., CISSN, CFL1., an exercise physiologist. “This is a low-dose X-ray that can tell you how much muscle, bone and fat mass you have,” she says. "Because it is an X-ray, it is able to segment your body parts and determine where and how much fat and muscle are distributed. It also tells you about your bone density, which is an important marker of bone health [is] important as you age," she adds. FYI, bone density refers to how strong and flexible the bones are, according to the Mayo Clinic. When bone loss occurs (e.g. due to osteoporosis), the bones become weaker and are at greater risk of fractures.

The overall composition of the tissues in your body, including muscle, bone and fat, is called your body composition. It's important to note that body composition is just a ratio of fat and lean mass (muscle and bone), says Olenick. This means that "sometimes a 'higher body fat percentage' does not indicate having 'too much fat,' but rather 'too little muscle,'" she explains.

The results of a full body scan are different from another metric you may be familiar with, body mass index (BMI), which is influenced by societal and racial biases. It proposes ideal health measurements based on the height and weight ratio of a sample of white European men. DEXA scans are calculated by comparing the averages of people of the same age and gender from a large national database, Olenick says.

Additionally, BMI is not an accurate measure of health because it is based solely on height and weight without taking bone density, muscle mass, and fat mass into account. This means that "many muscular athletes have an overweight BMI but can be very lean on a body composition scan," says Olenick. “Or someone could have a healthy BMI but need to build more muscle,” she explains.” A body composition scan “is a more honest and better look at your body,” says Olenick.

Why should someone get a DEXA scan?

A full body scan can provide you with important health information about your bone density. Anyone who has access to and can afford a DEXA body scan should get one, especially women and trans people, Olenick says. This is because estrogen levels drop in women or people who have previously menstruated during menopause, which can reduce bone density. That's one reason women have a higher risk of bone disease than men, Olenick explains. "It's especially important to have a baseline to know your bone density as you get older or if you go through menopause and are at higher risk of osteoporosis," she adds.

This type of scan is also helpful because it shows people how much muscle tissue they have, which is an important marker of health, says Olenick. Muscle mass “can prevent muscle loss and frailty” as you age, she explains. It also helps improve your quality of life and is important for metabolism, glucose regulation, and insulin resistance, adds Olenick. (See: Jane Fonda on the Importance of Staying Strong as You Age)

In addition to fat-free mass (bones, connective tissue, organ tissue and muscle tissue), a DEXA body scan also shows fat mass. Fat mass “is the adipose tissue (body fat) in which your body stores fat cells or other stored fat in the body.” While fat percentage is one piece of the puzzle here that can give you a better indication of overall health, it's important not to fixate on numbers. "People are also all built differently, and the way a certain body fat percentage looks on someone may look different on someone else if they store fat differently," says Olenick.

DEXA scans are particularly helpful for endurance athletes and anyone who has gone through a period of "extreme malnutrition or dieting," says Olenick. That's because these situations put a person at a higher risk of bone fractures.

What do the results of a DEXA scan mean?

Kardashian shared that her bones are stronger than 93 to 97 percent of people, based on the results of her scan, which included a "Z-score" of 1.3 out of two. "A bone density z-score is your score compared to the average scores of people your same age and gender from a large national database," says Olenick, who confirms that Kardashian appears to have healthy bone density. “I'm really happy to see that Kim has and promotes really healthy bone density in women,” says Olenick. "Higher bone density can help prevent stress fractures or major fractures as we age, or help with bone loss associated with menopause or aging or with restrictive diets," she continues.

The Skims founder also shared that she has 18 percent body fat (up from 25 percent last year), which puts her in the "athlete category," according to her Instagram Story. "Eighteen percent body fat is pretty lean for a woman, but it's also important to note that her previous body fat percentage of 25 percent was also perfectly healthy and also considered 'athletic,' depending on who you ask," says Olenick. “Typically, athletes are leaner or have more muscle tissue than less active people, depending on the sport they do, but this is not always true,” she adds. “People can have a higher body fat percentage than Kim or that category and be athletic or an athlete.”

While a full body scan can give you helpful information about your health, comparing your results to others, including celebrities, is not helpful. “Body composition scans are just a ratio at the end of the day,” says Olenick. “It’s important not to put too much weight on these numbers,” she adds.

So if you have access to a full body scan, it may be able to give you useful information about your body composition. Overall, however, the results of this type of test do not provide a complete picture of your health. If you have more specific questions about your own body composition, it is best to speak to your doctor who can give you personal advice.