According to the Centers for Disease Control and Prevention (CDC), obesity affects almost 42% of United States citizens. Obesity, or having a weight that is higher than what is considered healthy in comparison to one’s height, is determined by a screening tool called Body Mass Index (BMI). This index is widely used to understand if someone is underweight, at a normal weight, or overweight.
BMI Measurements
In order to calculate your BMI, divide your weight in kilograms, by your height in meters, squared. The CDC also offers an online BMI calculator. The CDC notes the following classes of weight:
• Underweight – BMI less than 18.5
• Normal Weight – BMI is 18.5 to 24.9
• Overweight – BMI is 25 to 29.9
• Obese – BMI is greater than 30
While BMI is a tool to help understand your weight, it is a snapshot and not a perfect reflection of your overall health. A health care provider will take your BMI and other health factors into consideration when evaluating your overall current status of or risks to wellness.
Shortcomings of BMI
Calculating your BMI is a convenient and inexpensive way for health care providers to get an estimation of your body fat percentage. However, it is important to take a few other matters into account when grading your health in general. BMI measurements are not the end all be all of your health for a few reasons.
Gender, age, ethnicity, and leg length all affect your BMI. Women tend to have a lower BMI than men even though their body fat content is higher. As we age, we also tend to lose more lean mass ultimately affecting your BMI.
BMI is a poor indicator of lean body mass because obesity is referred to as excess accumulation of body fat. BMI also does not tell us about the predominant fat accumulation location. Central fat, or accumulation of fat in our waist area, is more associated with bad outcomes including an increased risk of heart disease and stroke.
Additional Body Fat Estimation Methods
BMI is only one way to estimate the amount of fat on one’s body. A few other alternatives include:
• Bioelectrical Impedance Analysis – a low electrical current streams through the body to measure fat and muscle mass
• Dual Energy X-Ray Absorptiometry – a bone density scan
• Air Displacement Techniques – a calcium measuring procedure
• Techniques using isotope-labeled water – measures energy expenditure
• MRI – A magnetic resonance imaging machine uses radio waves and a magnetic field to create images of your physiological makeup.
• Measuring the circumference of your abdomen and hips
If you are concerned about your weight and if you feel like your health is being affected, make an appointment with your health care provider. They will go over any worries you may have and offer ways to help improve your well-being.
by Shivraj Goyal, M.D.
Internal Medicine, UPMC
Shivraj Goyal, M.D., is an obesity medicine specialist with UPMC Internal Medicine and sees patients at Emporium Health Center, 288 Sizerville Rd., Emporium. To schedule an appointment with Dr. Goyal, call 814-486-0810. For more information, visit UPMC.com/PrimaryCareNCPA.
