I have been overweight all my life and now my hips are so bad with arthritis I need replacements. The doctor has told me to lose weight, but how much is enough?

A recent report on 851 cases of total hip replacement included information on patient demographics. This refers to data about the patients' ages, gender, diagnosis, and body mass index (BMI).

BMI is calculated based on height and weight. It helps show how much body fat you have. Healthy risks from carrying too much weight include heart disease, diabetes, and arthritis.

A BMI in the "healthy" range does not always mean the person is fit and healthy. Poor diet and genetics can put an average person at risk for health concerns. Keep in mind the BMI does not take into account body frame. A muscular, large-framed person's BMI could indicate obesity, but this may not be the case.

The Centers for Disease Control and Prevention (CDC) offer a website with easy calculations of your BMI. You can do this by going to:

http://www.cdc.gov/nccdphp/dnpa/bmi/calc-bmi.htm

Once you've found your BMI ask your doctor about a reasonable weight loss plan. Studies show results after a hip replacement are best in patients with a BMI of 30 or less.