Overview
What is obesity?
Obesity is a complex, chronic disease with several causes that lead to excessive body fat and sometimes, poor health. Body fat itself is not a disease, of course. But when your body has too much extra fat, it can change the way it functions. These changes are progressive, can worsen over time, and they can lead to adverse health effects.
The good news is that you can improve your health risks by losing some of your excess body fat. Even small changes in weight can have a big impact on your health. Not every weight loss method works for everyone. Most people have tried to lose weight more than once. And keeping the weight off is just as important as losing it in the first place.
Is obesity defined by your weight?
Healthcare providers commonly use the Body Mass Index [BMI] to define obesity in the general population. The BMI measures average body weight against average body height. As a generalization, healthcare providers associate a BMI of 30 or higher with obesity. Although BMI has its limitations, it’s an easily measurable indicator and can help alert you to obesity-related health risks.
Examples of limitations include bodybuilders and athletes, who have more muscle and may have higher BMI scores even though their fat levels are low. It’s also possible to have obesity at a “normal” weight. If your body weight is average but your body fat percentage is high, you may have the same health risks as somebody with a higher BMI.
Healthcare providers have also observed ethnic differences in how much extra weight different people can carry before it affects their health. For example, people of Asian descent are more likely to have health risks at a lower BMI, and Black people are more likely to have health risks at a higher BMI.
Another way of assessing obesity is by measuring waist circumference. If you have more body fat around your waist, you are statistically more at risk of obesity-related diseases. The risk becomes significant when your waist size is more than 35 inches for people assigned female at birth or 40 inches for people assigned male at birth.
What are the three types of obesity?
Healthcare providers classify obesity into class types based on how severe it is. They use BMI to do it. If your BMI is between 25.0 and 29.9 kg/m², they put you in the overweight category. There are three general classes of obesity that healthcare providers use to evaluate what treatments may work best for each person. They include:
- Class I obesity: BMI 30 to