Americans are getting heavier and have been doing so for decades. One in three adults in the US is obese. Overweight and obese people are more likely to develop diabetes, high blood pressure, heart disease, and other serious health problems. What can be done?

Last month the US Preventive Services Task Force (USPSTF) released a new recommendation that all primary care doctors screen their patients for obesity. To do that, a doctor measures the patient’s weight and height and uses it to calculate the patient’s body mass index (BMI). Do you know your BMI? If not, use this handy BMI calculator to figure it out.

The BMI is a somewhat imprecise measure of healthy weight since it doesn’t take into account body fat percentage, but it’s easy to determine and therefore widely used. Normal weight for adults is from a BMI of about 20 to about 25. A BMI over 25 is considered overweight. Over 30 is obese.

The USPSTF recommends referring everyone with a BMI greater than 30 to an intensive behavioral intervention program that focuses on increasing exercise, controlling food portions, and self-monitoring progress towards weight-loss goals. Of course, eating better and exercising is notoriously difficult, and on average the long term weight-loss is only modest. But in obese people a loss of even 5% of weight is likely to lead to some health benefits. In any case, increasing physical activity and eating better is likely to lead to health benefits even if weight loss is not achieved, or if the weight is regained later.

The medications currently available for weight loss are only minimally effective and have some side effects, so the USPSTF did not recommend medication use. The current recommendations also did not evaluate surgery for weight loss, which has been gaining supporting evidence in the last few years.

So know your BMI. If it’s too high, that’s a good sign you should be eating less and moving more.

Learn more:

Obesity screenings for all American adults? Not so fast, some say (Booster Shots, the Los Angeles Times health blog)
Doctors Hesitant To Deal With Patients’ Weight Problems (Shots, NPR’s health blog)
BMI calculator (Centers for Disease Control and Prevention)
About BMI for Adults (Centers for Disease Control and Prevention)
Screening for and Management of Obesity in Adults: U.S. Preventive Services Task Force Recommendation Statement (Annals of Internal Medicine)