BMI stands for Body Mass Index and is a quick and easy method to determine if an individual is at a healthy weight. It is calculated by dividing weight in kilograms by height in meters squared, or weight (kg) / [height (m)]2. It can also be calculated by dividing weight in pounds by height in inches squared multiplied by 703, or weight (lbs) / [height (in)2] * 703. For ease, a BMI calculator can be found on the CDC’s website at http://goo.gl/rBQrrY.
The standard weight status categories associated with BMI ranges for adults are as follows:
18.5 – 24.9
Normal or Healthy Weight
25.0 – 29.9
30.0 and Above
For example, someone who weighs 95 kg (210 lbs) and is 1.778 m (70 in) tall has a BMI of 30.1 and a weight status of obese.
What BMI is not.
A common misconception is that BMI is a measurement of body fat. Because BMI does not consider body composition (proportion of fat and lean body mass), the BMI ranges shown above can falsely classify a body builder as obese. For example, when Arnold Schwarzenegger won the Mr. Olympia title, his BMI was 30.6. On the other end of the spectrum, a petite, sedentary woman who has a BMI of 23 can appear to be healthy because she is not overweight. However, her body fat could in reality be 35% and her risk for disease high.
By itself, BMI is not a complete measurement of health or fitness. To get a more comprehensive assessment, two other measurements to consider are waist circumference and body fat percent. Body fat percent can be measured by an experienced health and fitness professional using skinfold calipers. If you do not have access to a fitness facility that offers body fat analysis, BMI along with waist circumference is a useful place to start to determine your risk for obesity-related health problems. Waist circumference is measured at the smallest part of your torso below your rib cage and above your hip bones. A measurement of less than 35 inches for women and less than 40 inches for men is ideal.
I have calculated my BMI, now what?
Regardless of your BMI number, evaluating your eating habits and exercise routine can always be beneficial. Even if your BMI is in the healthy weight range, assessing the quality of your nutrition and physical activity and then making healthy changes accordingly can make a tremendous difference in your health and how you feel.
If your BMI is 25.0 or higher, you could be at a higher risk for health-related problems/diseases such as heart disease and diabetes, fatigue, and joint pain. Being overweight or obese can cause stress on the joints and lead to osteoarthritis. In fact, being only 10 pounds overweight increases the force on the knee by 30-60 pounds with each step. Losing weight through sound nutrition and exercise is a great way to keep your health and joint pain in check.
To improve eating habits, a great question to ask is “how can I eat to reduce inflammation?” One key place to start is by reducing and working toward eliminating added sugar. The obvious sources of sugar are candy, pastries, juice and sodas. Some less obvious foods include breakfast cereals, nutrition bars, flavored yogurt, condiments, most packaged snacks for kids, and foods labeled as non-fat or low fat.
Reading the nutrition facts and ingredients list on the foods you buy will be the best way to know if you are getting too much sugar. In the ingredients list, look for the different names for sugar such as corn syrup, high-fructose corn syrup, molasses, and maltodextrin. On the nutrition facts, look for the number of grams of sugar which should be 5 grams or less per serving. In addition, limit daily sugar intake to 25 grams for women and 37.5 grams for men.
Benefits of weight loss include lower blood pressure; improve sleep apnea; reduce risk of chronic diseases such as heart disease, stroke, cancer and diabetes; reduce inflammation and pain; increase energy; and improve mood. In addition to weight loss, other benefits to strength training include strong bones, reduced risk of osteoporosis, stamina boost, and healthier joints.
Take home message.
Calculate your BMI and start making healthy changes accordingly. Before you know it, you’ll be healthier, moving easier, have more energy and overall feeling good.