Question

What is the definition of obesity and what is the most common tool used to scientifically diagnose it?

Answer 1

Obesity is the condition of being grossly fat or overweight, and the most common tool to diagnose it is BMI, the Body Mass Index.

Answer 2

Obesity is an abnormal accumulation of body fat, usually 20% or more over an individual's ideal body weight. The most common tool to scientifically identify it is figuring out one's BMI (body mass index).