Editor’s Note: This post was updated on September 4, 2018, for accuracy and comprehensiveness. It was originally published on July 22, 2015.
Let’s say you are an office worker that may have gained a little bit of weight since starting your new job and you want to assess your body weight. If you are like most, you will use the Body Mass Index (BMI), which is commonly used by physicians, insurance companies, and regular people around the world to determine if a person is considered overweight or obese.
BMI scores are calculated from the US National Institute of Health
After you calculate your score, you compare your BMI score against the Body Mass Index ranges set by the World Health Organization.
Your BMI score of 23.9 falls between 18.5 – 24.9, so you are safe in the normal range. You will take it! But before you celebrate too much, consider this:
Body Mass Index was never intended to be used to measure individuals at all.
Here’s a quote from The World Health Organization:
The BMI provides the most useful population-level measure of overweight and obesity, as it is the same for both sexes and for all ages of adults. However, it should be considered as a rough guide because it may not correspond to the same body fat percentage in different individuals.
Despite this clear message, many doctors, physicians, and regular people continue to use BMI as a diagnostic tool simply out of convenience.
However, relying on BMI as your only health indicator can mask your risk for serious health issues because BMI can’t tell the difference between muscle mass and fat, and more importantly where the fat is distributed. You might have an unpleasant secret hiding behind that healthy BMI.
Let’s test the same individual using a medical-grade body composition analyzer.
Visceral Fat is based on the estimated amount of fat surrounding internal organs in the abdomen. It’s also suggested to maintain a level under 100 cm² to be healthy.
Although a higher than the recommended body fat percentage is what most people (and the media) focus on, this individual’s high visceral fat is actually the worst of the two. That’s because visceral fat acts like another living organ inside your abdominal cavity.
What is Visceral Fat?
Visceral fat is a special kind of fat that is hidden deep inside your abdomen and surrounds your inner organs. Everyone has some. Unlike surface level (subcutaneous) fat, it’s not easy to gauge how much visceral fat someone has just by looking at them. That’s because visceral fat is hidden away in the abdominal cavity, in between your organs.
If you rely on BMI as your primary tool to assess weight, you may have significant amounts of visceral fat and not know it.
Unlike the organs that you were born with that sustain life, visceral fat actively works from the inside out to sabotage those organs and ruin your bodily functions.
According to Harvard University, visceral fat secretes a number of hormones and chemicals. One group of these chemicals is called cytokines. Cytokines play an important role in the human body, but increased levels of cytokines due to excess visceral fat can be problematic. Once cytokines enter the liver, they influence the production of blood lipids, which has been linked to higher cholesterol and insulin resistance. This can lead to Type 2 diabetes.
Type 2 diabetes is typically associated with people who are overweight or obese, and individuals whose BMIs above the normal range (18.5-24.9) are said to be at a significantly greater health risk. However, BMI can misrepresent people who are either near or slightly over the 24.99 mark.
But that’s not all. Individuals with normal BMI but high visceral fat level share similar risk profiles as those who are visibly obese. Maintaining a high visceral fat can contribute to a myriad of health complications including high blood pressure, heart disease, cancer, and depression.
Depending on lifestyle factors, many people have a body profile like our example: large amounts of abdominal fat, yet a “normal” BMI because they don’t have much skeletal muscle mass. Due to the trend towards sedentary lifestyles, this is becoming more and more common.
The Visceral Fat Recipe
Excess visceral fat is unnecessary fat and develops as a result of having a caloric surplus. Unsurprisingly, visceral fat develops as a result of adopting unhealthy lifestyle habits. Some of these factors include:
- Little or no exercise or avoiding functional exercises that build muscle
- Poor diet, high in carbohydrates, saturated fat, and empty calories
- Poor sleep habits
- Excessive alcohol consumption
For people living sedentary lifestyles, it is quite easy to pick up several of these unhealthy habits. Over time, these habits will lead to increased amounts of body fat, including visceral fat.
Assessing Your Risk
Here are three options:
1. Waist Measurement
According to the Mayo Clinic, using a measuring tape to measure your waistline is a fairly good way to estimate your visceral fat content. If your waist measures over 35 inches for women or over 40 inches men, you may be carrying too much visceral fat.
2. Dual Energy X-ray Absorptiometry (DEXA) Scan
One of the most precise methods of determining the amount of visceral fat deposits is by taking a DEXA test. But this requires access to a facility that has a unit, and a test can be expensive.
3. Professional Bioelectrical Impedance Analysis (BIA)
A great alternative to a DEXA test may be a medical BIA test. These tests measure the resistance experienced by an electric current as it travels through your body to determine your body fat percentage, which includes your visceral fat. Advanced BIA devices that take direct segmental measurements are able to report visceral fat content, although you would need to ensure that the device you are using has this capability.
Knowing your body composition will give you a much better idea about your amount of visceral fat than BMI can. If your weight and/or BMI is considered “normal,” but your body composition test reveals if you have a high body fat percentage and low muscle mass (as with people who are skinny fat), you might want to consider making some lifestyle changes to reduce your risk of developing potentially serious health complications like heart disease in the future. If your body composition test provides your BMR, use that number to determine your daily calories needs as part of your weight loss strategy.
Hopefully, this clears things up for you. BMI cannot determine if you are lean, overweight, or somewhere in between. It’s all just raw numbers with BMI.
if you have a “normal” weight and BMI, don’t let your guard down! It’s easy to just fall into the trap and think “I may be chubbier but I’m not obese so I don’t have to think about weight loss; ” or “I guess I just have good genes so I’m always going to look underweight.”
No one should expect to eat a diet high in calories and saturated fat, totally ignore exercise, and expect to be healthy their entire life.
The good news is, if you exercise, watch your calories, and live a generally healthy lifestyle, you’re going to avoid gaining too much visceral fat as the result of the good choices you’re making. Body composition testing will always give you much more information than your BMI ever will, and can give you a much better picture of everything that makes up your weight, including your visceral fat. Remember “what gets measured, gets managed” so go take a body composition test and find out visceral fat level!