Overweight - body mass index; Obesity - body mass index; BMI
Overweight and obesity mean having a weight than is higher than what is healthy for a given height. A person may be overweight from extra muscle, bone, or water, as well as too much fat. But both terms mean that someone's weight is higher than what is thought to be healthy for their height.
More than 1 out of every 3 adults in the United States is overweight.
Experts often rely on a formula called body mass index (BMI) to determine if a person is overweight. BMI is used to estimate your level of body fat based on your height and weight.
- A BMI from 18.5 to 24.9 falls within a healthy weight range.
- A BMI of 25 to 29.9 falls within the overweight range. Since BMI is an estimate, it is not accurate for all people. Some people in this group, such as athletes, may have a lot of muscle weight, and therefore not as much fat. These people will not have an increased risk of health problems due to their weight.
- A BMI of 30 or higher falls within the obesity range.
- Class 1: BMI of 30 to less than 35.
- Class 2: BMI of 35 to less than 40.
- Class 3: BMI of 40 or higher. Class 3 is considered "severe obesity."
The risk for many medical problems is higher for adults who have excess body fat and fall into the overweight groups.
CHANGING YOUR LIFESTYLE
Your main goal should be to learn new, healthy ways of eating and make them part of your daily routine.
Many people find it hard to change their eating habits and behaviors. You may have practiced some habits for so long that you may not even know they are unhealthy, or you do them without thinking. You need to be motivated to make lifestyle changes. Make the behavior change part of your life over the long term. Know that it takes time to make and keep a change in your lifestyle.
Work with your health care provider and dietitian to set realistic and safe daily calorie counts that help you lose weight. Keep in mind that if you drop your weight slowly and steadily, you are more likely to keep it off. Your dietitian can teach you about:
Cowley MA, Brown WA, Considine RV. Obesity: the problem and its management. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 26.
Jensen MD. Obesity. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 207.
Jensen MD, Ryan DH, Apovian CM, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and The Obesity Society. Circulation. 2014;129(25 Suppl 2):S102-S138. PMID: 24222017
Semlitsch T, Stigler FL, Jeitler K, Horvath K, Siebenhofer A. Management of overweight and obesity in primary care - a systematic overview of international evidence-based guidelines. Obes Rev. 2019;20(9):1218-1230. PMID: 31286668
Last reviewed on: 8/13/2020
Reviewed by: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 05/23/2022.