Dr. Ellen Schur talks to Steve Scher about our bodies internal regulatory systems and how they change as we gain weight. She says the body's changes mean that simply exercising more and eating less is not the only factor to consider when we try to lose weight.

Obesity is medically defined through the body mass index – BMI- an indirect measure of how much body fat a person carries. BMI is your weight in kilograms over your height in meters. Though Dr. Ellen Schur says it’s somewhat arbitrary and is dependent on the person, the cut off for obesity is a BMI of 30. Overweight is 25-29, normal weight 18 and half to 20. Dr. Schur is Associate Professor of Medicine in the Division of General Internal Medicine, University of Washington, Co-Director, UW Medicine Weight Loss Management Program. She is part of the UW’s Weight and Wellness Lecture Series spring, 2015.

So when to worry?

When people are in the overweight category, are they showing signs of changes that affect health? Are the blood sugars starting rise, is blood pressure starting to rise? Is the body weight tending to settle in the persons middle rather than in the hips or extremities? Any of these factors, in combination with a body mass that’s in the overweight range, puts people at higher risk for various disorders. Losing some weight is recommended.

At this point, the connection between weight and wellness is pretty clear, according to Dr. Ellen Schur, Once we get obese, our body's internal regulatory systems change and it is going to take a lot more than simply exercising more and eating less to stay healthy.

The newest thinking among medical specialists is that obesity is a disease and we need to treat it the way we treat other diseases.

Just as with high blood pressure, doctors don’t expect a person’s will power will bring their weight down. At the point when we are overweight, all sorts of interventions are necessary, including permanent changes to lifestyle habits and medications.