DEAR MAYO CLINIC: Is it possible to be 30 pounds overweight and still be healthy? My blood pressure and cholesterol are normal, and I have no health issues other than being overweight.

ANSWER: Weight is one important measure of health. But it's not the only thing to be considered when assessing how healthy you are overall. Other factors play a role as well, such as how active you are and the amount of muscle vs. fat you have in your body. Taken together, these variables can help give you a more comprehensive view of your health, now and into the future.

Health care providers often assess the impact of a person's weight on their health using a calculation called the body mass index, or BMI. BMI is calculated by dividing your weight in kilograms by your height in meters squared. To find your BMI quickly, you can go to Mayo Clinic's website at http://www.mayoclinic.org, and enter your height and weight into the site's online BMI calculator.

BMI values that are between 18.5 and 24.9 are considered normal. Values between 25 and 30 are considered overweight, and values greater than 30 are considered obese. Generally, a BMI that's more than 30 is associated with higher risks to health. These risks include a higher likelihood of developing diseases and health problems such as heart disease, diabetes and high blood pressure.

However, BMI doesn't always provide the full story regarding health risks for some people. That's because it does not take into consideration body composition, particularly the percentage of your body that is fat vs. muscle.

For example, if you lead a very active lifestyle, regularly participating in both aerobic exercise and weight training activities, you may have a healthy percentage of body fat despite having a BMI above the normal range. So, in that situation, a higher BMI does not necessarily translate to higher health risks. It's important to note, though, that this situation is less likely when BMI values are higher than 35. Beyond that point, additional weight is much more likely to be distributed as fat and not muscle.

It's also possible to have a normal BMI while your body fat percentage is high enough to increase health risks. People with this condition, known as normal weight obesity, may have the same serious health risks as does someone who is obese. This is especially true for individuals who have a high percentage of body fat around the waist. Research has shown that people who carry a high proportion of body fat at the waist have increased health risks.

To get the most accurate assessment of your health, first find your BMI. Then, take a look at your lifestyle. If your BMI is less than 35 and you exercise regularly -- participating in at least 150 minutes of physical activity a week -- you may not be at an increased health risk. If your BMI is 30 or higher, and you don't have an active lifestyle, your health may be at risk. If so, talk to your health care provider about changes you may be able to make to improve your health now, as well as lower your risk for health problems in the future. -- Maria Collazo-Clavell, M.D., Endocrinology, Mayo Clinic, Rochester, Minn.

(Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care. E-mail a question to medicaledge@mayo.edu. For more information, visit http://www.mayoclinic.org.)