Obesity (oh-BEE-si-tee) Obesity is excess body fat. Because body fat is usually not measured, a ratio of body weight to height [see body mass index, or BMI, chart] is often used instead. It is defined as BMI. An adult who has a BMI of 30 or higher is considered obese.
Overweight It is defined as a body mass index (BMI) of 25 to 29.9. Body weight comes from fat, muscle, bone, and body water. It is important to remember that although BMI correlates with the amount of body fat, BMI does not directly measure body fat. As a result, some people, such as athletes, may have a BMI that identifies them as overweight even though they do not have excess body fat.
Overweight refers to an excess of body weight compared to set standards. The excess weight may come from muscle, bone, fat, and/or body water. Obesity refers specifically to having an abnormally high proportion of body fat.[1] A person can be overweight without being obese, as in the example of a bodybuilder or other athlete who has a lot of muscle. However, many people who are overweight are also obese.