Definition of Obesity for Adults

Discover the background on the definition of obesity

Overweight and Obesity is an imbalance between calories in versus calories out. Basically, the calories you consume through food and drinks versus, the calories you expend through physical activity. If you consume more calories then you give off, then you will gain weight. For adults, an accurate measurement of weight and height can be used to determine overweight or obesity. Body Mass Index (BMI) is calculated as:

Weight in kilograms (kg) divided by the square of height in meters (m2)

BMI= Weight (kg) / Height (m2)

BMI= Weight (lbs) / Height (in2)x 704.5

• Underweight is a BMI or less than 18.5.
• Normal is considered 18.5-24.9.
• In adults, a BMI of 25 kg/m2 or more is overweight.
• Obesity is defined as a BMI of 30 kg/m2 or more.
• Obesity class I is 30.0-34.9
• Obesity class II is 35.0-39.9
• Obesity class III is 40 or more

These ranges are useful to see where you fall in the healthy weight scale. Please keep in mind that BMI does not directly measure body fat. An athlete may have a BMI in the overweight category, but they will not necessarily have excess body fat due to increased muscle mass. Other assessments, such as waist-to-hip ratio, waist circumference, and Skinfold thickness measurements may also be used to determine body fat and body fat distribution.

The effects of Overweight and Obesity result in an increased risk of illness for high blood pressure, high cholesterol, type 2 diabetes, heart disease and stroke, gallbladder disease, arthritis, sleep disturbances and problems breathing, and certain types of cancers

Continue to:
Obesity Definition continued: waist to hip ratio

Site Navigation:
Home Definition of Obesity