You exercise regularly and are mindful of diet, but your weight is still stuck in the overweight or obese body mass index (BMI) category. That yearly physical is looming, and you know your doctor is going to bring up that BMI. Sound familiar?
Or perhaps you have lost weight and your body has completely plateaued, or maybe you are just having a difficult time maintaining weight loss. If you are frustrated by a similar scenario and wonder whether your body weight classifies you as "unhealthy," it may be time to consider research indicating that it’s possible to be "fit but fat." Current studies investigating this concept generally use healthy cardiovascular/metabolic profiles as a determining factor. For example, are blood lipids, blood sugar, and inflammatory markers within normal limits? If you are overweight and have been diagnosed with diabetes or heart disease, lifestyle changes to improve your health are still recommended.
BMI doesn’t take into account muscle mass versus body fat and, therefore, I encourage my clients to view BMI as only one part of the picture for weight status. For a clearer picture, it’s important to get an estimate of body fat percentage and where extra body fat is stored (on the abdomen as opposed to on the hips, for example). When combined with BMI, this information can give more information about body composition and how it may affect overall health. Additionally, I encourage clients to think about what they eat and how their dietary lifestyle plays a role in extra weight. Sandra Adamson Fryhofer, M.D., asked this question in The Obesity Paradox: Does it Matter?: "Did those excess pounds accumulate through ingestion of healthy foods from a healthy diet, such as one comprising nuts, low-fat dairy, whole grains, fruits, vegetables and omega 3-rich foods like salmon? Or did the extra calories accumulate through excess consumption of ‘empty calorie’ foods?"
One of the keys to the "fit but fat" theory is physical activity, as Steven C. Moore, Ph.D., explained in an article published in Medscape Medical News entitled "Fit, Yet Fat?: A Little Exercise May Add Years to Life." Moore is the co-author of a study that examined the increased life expectancy associated with physical activity during leisure hours and at different BMI levels. The researchers found the relationship between fitness and life expectancy was true regardless of BMI and wrote, "At the minimum recommended physical activity level… equivalent to 150–299 minutes of brisk walking per week—the gain in life expectancy was 3.4 years." Translation: Regardless of BMI or weight status, a moderate amount of physical activity has the potential to add years to life.
Other studies have confirmed the importance of fitness regardless of weight status. Dr. Barry Vaughn and other researchers at Middle Tennessee State University found that "fit individuals who are overweight or obese are not automatically at a higher risk for all-cause mortality." They went on to state, "These findings are promising for all individuals, including those unable to lose weight or maintain weight loss, as all can experience significant health benefits by developing and maintaining a moderate level of cardiorespiratory fitness by participating regularly in physical activity at the level of physical activity currently recommended by the U.S. Physical Activity Guidelines."
What are the current U.S. Physical Activity Guidelines? For adults ages 18–64, weekly exercise recommendations include 2 hours and 30 minutes of moderate-intensity exercise, 1 hour and 15 minutes (75 minutes) of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic physical activity. If a busy schedule creates barriers to physical activity, recognize that breaking activity into 10- or 15-minute segments can still have the same positive effect as continuous exercise.
A common trap for many is increasing food intake beyond what is needed to facilitate exercise. I wish it weren’t so, but exercising doesn’t provide a hall pass to eating thoughtlessly and consuming more than is needed. It’s important to remember to practice moderation and consider exercise as a mechanism for improving overall health, not just as a tool to change physical appearance. The "fit but fat" studies are not an argument for remaining overweight or obese; they are, however, unique in the sense that these studies can open to the door to a conversation with your doctor regarding overall health, genetic risk factors, and how fitness can play a role in decreasing risk of disease.