Medically Reviewed On: July 10, 2008

VAREN BLACK: I'm Varen Black. Welcome to Chicago Health, where we talk to some of the best minds in medicine who live right here in our city.

We all know what too much steak and sausage can do to our waistlines. Nobody likes going up a size. But suffering from obesity is another problem all together.

Joining me to talk about obesity and its consequences is Dr. Robert Kushner, Director of the Wellness Institute at Northwestern Memorial Hospital.

Dr. Kushner, how big is the problem of obesity?

ROBERT KUSHNER, MD: It's the most serious problem we are facing today. Next to cigarette smoking, overweight is the second leading cause of preventable death in this country. It's estimated that 300,000 deaths per year is attributable to our diet, physical inactivity and resulting obesity.

VAREN BLACK: A fourth of American adults are obese?

ROBERT KUSHNER, MD: One in four is obese, and about one in three is considered overweight. Combined, over 60 percent of adult Americans are now overweight or obese. That means that the minority of this population is able to maintain a healthy body weight.

VAREN BLACK: We're now hearing a lot about children being obese. What is the number there?

ROBERT KUSHNER, MD: Well, there it's about 1 in 10 or 10 percent. The troubling factor there is that they are following in our oversized footsteps. An overweight or obese child is more likely to be an obese adult. So we are unfortunately looking at an epidemic among our children as they become adults, and are likely to be more obese than we are today.

VAREN BLACK: Why has the number of heavy people increased?

ROBERT KUSHNER, MD: That's still debatable, and a lot of research is looking into that. But most of us think that it's due to our society and culture. We really live in an obesogenic society where food is plentiful, physical inactivity is everywhere.Those two combined leads to gaining weight.

VAREN BLACK: How is obesity defined?

ROBERT KUSHNER, MD: We currently define obesity by using a term called the body mass index, also known as the BMI. Of course, everyone knows their cholesterol and everyone knows their blood pressure. It's equally important that everyone knows their BMI. It's a weight for height relationship that's fairly easily calculated on tables. A BMI between 25 and 30 is defined as overweight. A BMI of 30 or more is obese.

Roughly speaking, about 30 or more pounds overweight already defines one as obese.

VAREN BLACK: Just 30 pounds?

ROBERT KUSHNER, MD: Just 30 pounds. It doesn't take much to have the health complications that are associated with obesity.

VAREN BLACK: Talk about those complications, the health effects of obesity.

ROBERT KUSHNER, MD: Obesity is the major cause of type 2 diabetes in this country. Obesity is the number one reason why diabetes is increasing in this country. It is fueling that disease. In addition to diabetes, obesity is also linked to increased risk of high cholesterol, high blood pressure, gastroesophageal reflux disease, certain cancers, in addition to psychological and emotional problems, as well as quality of life changes. It eventually leads to earlier death.

VAREN BLACK: What are the leading causes of obesity?

ROBERT KUSHNER, MD: The most significant factor really is our lifestyle. That's the only way that we can understand why the numbers of obese patients or individuals has risen so quickly. Again, that's the food that's everywhere and the physical inactivity.

But what's also important to mention is that genetics plays a role. We currently think that genetics determines a vulnerability to our environment which then brings out the obesity.

There are other causes, although less common. They include, drug induced obesity, such as people on different corticosteroids,different hormonal agents, people with diabetes. Those medications can increase body weight, not to mention things like antidepressants and other drugs used for mental health disorders.

Rarely is an underlying medical condition a cause for obesity. That would be something like Cushing's syndrome or different kinds of glandular problems. But they are, once again, very uncommon.

VAREN BLACK: What is the first step in getting treatment for obesity? Where does a person go for help?

ROBERT KUSHNER, MD: There are several places an individual can go for help. One is, and the first that I would recommend, is to see his or her doctor. A doctor should be playing an active role as a partner in helping you get control of your body weight. The doctor can also make sure that you don't have an underlying problem that's being caused from the obesity or causing the obesity itself. That needs to be ruled out right away. Once you've done that, you can either work with your doctor or work with a registered dietitian or seek help with some of the commercial programs that are available that can be very helpful.

VAREN BLACK: Thank you so much for being with us. I'm glad we had the chance to talk to you about it and learn more about obesity.

ROBERT KUSHNER, MD: You're welcome. Thank you for having me.

VAREN BLACK: You're welcome. And thank you for being with us. I'm Varen Black.