The Body Mass Index (BMI) is a tool to help evaluate overall health relative to height vs. body weight. It is a formula as follows:
Height (in inches)/(weight in lb squared) x 703
The BMI is NOT a direct measurement of body composition or body fat. However, for most people, it correlates well with body fat. The BMI is how we categorize people's health risk based on their body weight. The higher the BMI the higher the risk. The BMI categories are based on the relationship between weight, disease, & death.
The BMI is an objective measurement of height versus weight. It is a screening tool to help identify who needs further testing.
People who are very lean AND muscular may have a higher BMI and may be categorized as overweight or obese. For most people, however, the BMI is an accurate tool.
The categories are as follows:
- Underweight: <18.5
- Normal weight: 18.5-24.9
- Overweight: 25-29.9
- Obese: 30-39.9
- Morbidly Obese: >40
As stated above, the higher your BMI the higher your risk for many medical problems such as:
- Type 2 Diabetes
- Coronary Artery Disease
- Gall bladder disease
- Sleep Apnea
- Cancer (some, such as breast, colon, and endometrial)
The bottom line is that unless your body fat percentage is less than 15% AND your BMI puts you in the overweight or obese category YOU NEED TO LOSE WEIGHT!
Here are some additional resources regarding weight & BMI
- CDC BMI page
- My weight loss page
- National Heart, Lung, and Blood Institute's BMI page
- BMI Calculator
- The Biggest Loser