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Understand Your BMI and Eligibility for Weight-Loss Surgery

Your body mass index (BMI) measures your weight relative to your height and is a reliable indicator of body fatness.

The ideal body mass index falls in the range between 19 and 24.9. If your BMI is greater than 30, you are considered obese and may be a good candidate for weight-loss surgery.

The higher your body mass index, the greater your risk of disease, including heart disease, high blood pressure, sleep apnea and type 2 diabetes. More than 300,000 lives in the United States could be saved each year if everyone stayed at a healthy BMI. You can check yours by using the BMI calculator on this page and then reviewing the chart below to see if your health is at risk.

Making Sense of the Numbers

BMI is calculated in the same way for both adult men and women and is based on a mathematical formula that compares height to weight. BMI is calculated by dividing body weight (lbs.) by height in inches squared (in2) and multiplying that amount by 703.

The ideal body weight for your height should result in a body mass index between 19 and 24.9. If you have a BMI above 30, you are considered obese and may be a good candidate for weight-loss surgery.

The standard weight categories associated with body mass index are shown in the table below.

BMI Chart

Below 18.5
18.5 - 24.9
25 - 29.9
30 - 34.9
35 - 39.9
40 - 49.9
50 ≤
Weight Status
Severely Obese
Morbidly Obese
Super Obese
Health Risk*
Very High
Extremely High
Extremely High

* Health risks include type 2 diabetes, hypertension and cardiovascular disease.

BMI is calculated from an individual's body weight which includes both muscle and fat. As a result, some individuals may have a high BMI but not have a high percentage of body fat. Although some people with a BMI in the overweight range (25 to 30) may not have excess body fat, most people with a BMI in the obese range (equal to or greater than 30) will have an increased level of body fat.

Who is a Candidate for Weight-loss Surgery?

Body mass index is not the only factor used to measure obesity and the risk for disease. Physicians at UC San Diego Health's Bariatric and Metabolic Institute will employ additional methods to determine your individual health status and create a treatment plan specifically for you.

Eligibility Criteria

Bariatric surgery may be right for you if your BMI is over 30 and you meet the following criteria:

  • You are severely overweight.
  • You have been overweight for more than five years.
  • Your serious attempts to lose weight have led to only short-term success.
  • You do not have any other disease that may have caused your obesity.
  • You are prepared to make substantial changes in your eating habits and lifestyle.
  • You are willing to follow a pre-operative nutritional program to prepare you for the procedure.
  • You are willing to continue being monitored by the specialist who is treating you.
  • You do not drink alcohol in excess.

Weight-loss Surgery is Not for Everyone

Bariatric surgery may not be right for you if:

  • You have severe heart or lung disease that makes you a poor candidate for surgery.
  • You have some other disease that makes you a poor candidate for surgery.
  • You have a problem that could cause bleeding in the esophagus or stomach. This might include esophageal or gastric varices (dilated veins), or congenital or acquired intestinal telangiectasia (dilation of a small blood vessel).
  • You have portal hypertension.
  • Your esophagus, stomach or intestine are not normal (congenital or acquired). For instance, you might have a narrowed opening to any of these organs.
  • You have or have experienced an intra-operative gastric injury, such as a gastric perforation at or near the location of the intended band placement.
  • You have cirrhosis.
  • You have chronic pancreatitis.
  • You are pregnant.
  • You are addicted to alcohol or drugs.
  • You have an infection anywhere in your body or one that could contaminate the surgical area.

Through extensive evaluation and consultation, we will help you determine if you are a candidate for bariatric surgery.

Make the first step to a healthier future. Call: 858-657-8860

BMI Calculator