Obesity is a disease that is defined as abnormal or excessive fat accumulation that may impair health by different mechanisms that are beyond the scope of this article.

To measure normal weigh, overweight and obesity, we implement a measure called BMI or Body Mass Index, which is a person’s weight in kilograms divided by the square height in meters. That gives us a number that can be compared with a specific table to know if you are overweight, obese or severely obese (morbid obesity). Here we have an example:

• If your BMI is less than 18.5, it falls within the underweight range.
• If your BMI is 18.5 to 24.9, it falls within the healthy range.
• If your BMI is 25.0 to 29.9, it falls within the overweight range.
• If your BMI is 30.0 or higher, it falls within the obese range.

Obesity is frequently subdivided into 3 categories:
• Class 1: BMI of 30 to 34.9, is categorized as obese.
• Class 2: BMI of 35 to 39.9, is categorized as severely obese.
• Class 3: BMI of 40 or higher is categorized as morbidly obese.