BMI, Body Shape and Body Composition, pt. 1 of 3
When I was working as a Wellness Coach and Personal Trainer at the Marin YMCA, I was asked many questions about BMI, Body Shape and Body Composition. Most people understood a little bit about each of them, but often did not connect the importance of these measures to overall health.
Keeping track of your health profile is important and ensures that if your health is changing you can stay ahead of it. A good practice is to weigh yourself weekly, take body measures monthly and see your doctor for a total body check-up yearly.
SUMMING IT UP
Measuring your health profile is complicated and no perfect method exists. No single test can give you your full health picture, but BMI is a fairly good predictor of body fatness for normal populations and can be a good starting place for measuring health .
WHAT IS BMI?
BMI stands for Body Mass Index. It estimates body fatness based on your height and weight.
WHY IS BMI IMPORTANT?
BMI tells you whether you're at an average weight, underweight, overweight or obese. The higher your BMI, the greater your risk of developing weight-related medical conditions, such as type 2 diabetes, cardiovascular disease, cancer, sleep apnea and stroke.
A study published by The Lancet in 2009, measuring 900,000 adults, showed that overweight and underweight people both had a death rate higher than average weight people as defined by BMI . The ideal BMI was found to be 22.5–25.
The CDC states a BMI range of 18.5-24.9 classifies an average weight for adults.
Adult BMI falls into the following ranges:
- underweight: less than 18.5
- average weight: 18.5 to 24.9
- overweight: 25 to 29.9
- obese: 30 and greater
- severely obese: 40 or higher
FIND YOUR BMI
- Use this BMI Calculator or BMI Chart to learn your BMI.
- Use the BMI calculator for children (ages 2 to 19) to see if your child is at a healthy weight.
WHAT BMI DOESN'T DO
BMI ignores variations in physical characteristics. For example,
- A tall man with a slender frame may be classified as "average weight" but actually be overweight if he's carrying extra weight on his slender frame.
- A shorter, muscular female athlete may be classified as "overweight" but actually be quite healthy, and carrying extra weight primarily in muscle mass (we might think of her as being overweight, but not over fat).
- Read about Body Shape in part 2 of this series.
- See a Wellness Coach
WELLNESS COACHING AT THE Y
Our fantastic team of Wellness Coaches can support you in setting healthy living goals. They'll introduce you to fitness equipment and show you how to use it, talk to you about available group exercise classes and explain the benefits of our many healthy living programs. They can also help you determine your BMI.
As a Y member, you have access to all YMCAs in San Francisco, San Mateo and Marin counties, including our Wellness Coaching team. Make a wellness appointment today!
- Prospective Studies Collaboration (2009). "Body-mass index and cause-specific mortality in 900000 adults: collaborative analyses of 57 prospective studies". Lancet. 373 (9669): 1083–96. doi:10.1016/S0140-6736(09)60318-4. PMC 2662372.
- Centers for Disease Control and Prevention. "Assessing Your Weight - Healthy Weight."
- Heart and Stroke Foundation of Canada. "Assess your weight."
- ACE Fit Share. "What are the guidelines for percentage of body fat loss?"
- The Daily Burn. "The 5 Best Ways to Measure Body Fat Percentage."