Normal Weight Obesity

By: Alex Michaels

Over time, society has come to recognize an individual as being healthy or unhealthy based on his or her outward appearance of body weight.  A person who appears to have a normal weight is obviously healthier than an obese individual, right?  Well, not so fast.  Often times, people who have what is considered normal weight can still have weight-related health issues.   This has become known as the term, “normal weight obesity” and there are a few factors that can help determine if a person has NWO.

First, it is important to understand BMI.  BMI stands for body mass index, which is a person’s weight in kilograms divided by their height in squared meters.  Below, the diagram displays the different categories that BMI represents.  

Being that it is a quick and easy way to determine a general weight status, it has been widely used the past few decades.  However, there are a few flaws associated with this method.  It does not take into account the added muscle composition that an athlete may have, nor does it take into consideration central adiposity (body fat around the waist).  It is simply a ratio of weight to height.  Another tool, measuring body fat percentage, is much more useful in determining a person’s level of risk for developing weight-related diseases such as cardiovascular disease, hypertension, and dyslipidemia.   That being said, doctors need to include body fat testing as part of health assessments and patient check-ups.  

What exactly is normal weight obesity?  It may sound confusing, but it is simply a person who has what is considered a “normal” BMI, but they have a high percentage of body fat making up their total body composition.  A shocking 30 million Americans are said to have NWO (Today’sDietician).  Body composition is made up of lean mass (muscle, organs, bone),  fat mass, and water.  Individuals with NWO usually appear to be in good shape and have no idea how high their body fat percentage is.  A study published in the European Heart Journal, March of 2010, found that a group of subjects with the highest body fat percentage (greater than 23.1% in men and greater than 33.3% in women) had four times the amount of metabolic syndrome compared to the group of subjects with low body fat.  The higher percentage group also had a higher prevalence of dyslipidemia, hypertension in men, and cardiovascular disease in women.  Overall, the BMI number should not be the only deciding factor when it comes to weight status and more focus on body composition must be a priority.

How can NWO be improved?  An important factor to remember is that NWO individuals do not necessarily need to lower the number on the scale, they need to change what is making up the ratios of their total weight in pounds.  The main step towards improving body composition is to implement more strength training into an exercise program.  This will help to increase the lean muscle mass in the body as well as improve bone mineral density.  Another way to lower body fat percentage is to eat a healthy diet with proper portion sizes in order to minimize the chance of storing extra calories not used for energy as fat.  Lastly, re-check body composition no less than four to six weeks at a time as it takes at least that much time to lose one to two percent of body fat.  


Check out the chart below.  Do you know what your current BF% is?

The science involving the human body is constantly evolving.  Despite the fact that BMI has been used for several decades to help determine weight status does not mean that it should remain the only standard forever.  The more awareness normal weight obesity receives, the more people will be able to take a closer look at their health in order to improve body composition and long term quality of life.  The scale weight is not the be-all, end-all.