Obesity Research May Shed New Light on Weight Loss

Arthur L. Caplan, PhD; Judith Korner, MD, PhD


July 06, 2015

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Arthur L. Caplan, PhD: Welcome to Close-Up With Art Caplan. This is an interview program where we speak with leaders in the field of healthcare. I am very excited to have Dr Judith Korner with me today. Dr Korner runs the Weight Control Center at Columbia University Medical Center in New York City, where she is also a professor of medicine. Thank you for joining us.

Judith Korner, MD, PhD: Thank you. My pleasure.

Dr Caplan: This is a topic I dread, and yet I am super-interested in it. I battle weight issues, and I have lots of friends who battle weight issues. Having the chance to speak with someone who is an expert on these problems will be of great interest not just to me but to our viewership. Certainly obesity and weight are major health issues. Tell me about your research.

Dr Korner: I am trying to figure out why people are hungry and how they get full because I believe that we are learning that appetite is regulated. For example, one slice of pizza may be enough to satisfy one person, whereas another person may need to eat half the pizza. But it is not always that the one-slice person is exercising willpower; it may just mean that they are getting signals—hormonal signals and signals from the gut—that the other person is not receiving.

We are learning that the gut is an endocrine organ, and when you eat, it sends out hormones that actually talk to the brain.

Dr Caplan: I am full. I am not full. I want some more.

Dr Korner: Exactly. There are cues that signal when you should be hungry and how much food it takes for you to become full. That is a huge interest of mine and what I am trying to figure out. The idea is that if we could figure that out, then perhaps we could develop targeted therapies.

Dr Caplan: We hear so much these days about obesity and research into obesity. Do we really understand why people are overweight?

Dr Korner: We are starting to. There has been a huge shift in the field within the past 20 years, since the hormone leptin was discovered. Leptin is made in fat tissue, and it talks to the brain, telling it how much fat is available. We have now discovered dozens of other hormones involved in that feedback to the brain, some coming from the stomach, some coming from the intestine, some from the fat tissue.

Dr Caplan: I believe they are coming from every part of me, so lots of signaling centers.

Dr Korner: Yes. We are trying to understand how those signaling centers work. Most likely, people are obese or they eat for different reasons. We are trying to figure out where their signaling centers may be off.

Dr Caplan: Everywhere I go, people are talking about genes and their relationship to obesity. Are we paying too much attention to genetics when we start thinking about causes of obesity?

Dr Korner: I have a 16-year-old son, and I can assure you that he thinks mothers are to blame for everything. Having said that, I believe genetics is a strong contributor to people's body weights, probably contributing from 50% to 80%. We are just trying to find which genes are involved. In some cases, we can clearly identify a mutant gene, for example, in the leptin receptor, but the number of those cases is really small. Most likely, obesity results from a group of different genes that work together in this environment and cause someone to eat more and become obese. The genes were around eons ago, pretty much the same genes. Long ago, they probably contributed to survival because those individuals who could hold onto body fat in times of famine would be the ones to survive; whereas now in developed countries, famine is not necessarily an issue. But if you have those genes, when you go to a drugstore to buy a pack of tissues, but next to the tissues you see the candy bars, you may go for the candy bar.

Dr Caplan: Some rare genetic diseases do seem to be closely associated with overeating and with putting on weight. Do they have anything to teach us about obesity?

Dr Korner: Some conditions that are genetically based do drive overeating. For example, Prader-Willi syndrome causes excessive hyperphagia, and we know that levels of one of the hunger hormones are increased with that. There is also a mutation in the melanocortin-4 receptor in the hypothalamus. This receptor receives signals to suppress appetite and increase energy expenditure. That is probably the most common gene that we know of that is linked to early-onset obesity. Depending on the study, its prevalence is between 4% and 6% of the population. For the rest of the population, we are not sure what genetic drivers are responsible for obesity.

Dr Caplan: Let me ask a different question. Some say that we put too much attention on the genetics and the heredity. I once counted fast food outlets when I was driving home from Philadelphia to the suburbs. I went by 11 fast food outlets. They are everywhere. Portion size in the United States is enormous. If someone comes here from Europe, they think there is enough food on a plate to last us a week. Are we in a culture that makes us fat?

Dr Korner: Some people term this an obesogenic environment. If you look at restaurant menus, the average meal in a restaurant is now four times higher in calories than a restaurant meal in the 1950s.

Dr Caplan: Really? Wow.

Dr Korner: And our portions have gone way out of control. When you go to a movie theater, for 25 cents more, you can get the huge tub of soda instead of the small container of soda. The environment is extremely important.

Dr Caplan: Is that a war medicine can win? You have the Colonel and Ronald McDonald and Burger King on one end, and you and an apple on the other. Can we really win this fight?

Dr Korner: I hope we can. It seems overwhelming, but we need to keep going on with the battles. I believe that every little battle we win will eventually lead us to a healthier environment. Certainly we now have more awareness of healthier eating, in public schools and vending machines, for example.

Dr Caplan: Do you support efforts to get the soda out of the schools and so on?

Dr Korner: Yes. But there also has to be parental education.

Dr Caplan: Do we really have to teach people how to eat? Is that an important thing to pay attention to?

Dr Korner: Absolutely. We need more nutritional education, and it has to be for all of the family members. As physicians, we need to learn a bit more about nutrition. Right now, many physicians do not address nutrition with our overweight or obese patients. It is a very sensitive topic. But then if we do, we may say, "You have to lose 30 pounds," and leave the patient on his own to accomplish this. No one is helping that person figure out how they are going to lose the 30 pounds.

Dr Caplan: It is interesting. I will just tell a story on myself. I have been losing a couple of pounds a month for the past year or so. I like to eat a lot, so my doctor manages me by seeing me a lot. We just do check-ins and talk about how I am doing, I am weighed, and it makes me more accountable. More frequent checking and support may be one strategy.

Dr Korner: There is a lot of data to support what you have just said. Accountability, support—support from many different sources—and because each person is a bit different, the approach needs to be tailored to the patient. Some people may like a group setting; some people may like an individual setting.

Dr Caplan: You have to figure out what they respond to best?

Dr Korner: You do. Unfortunately, doctors have very little time in their practices to devote to nutrition education.

Dr Caplan: Although obesity is such a big health issue, you would think—

Dr Korner: Right. If you could tackle that, you may not need to tackle the high blood pressure, the high blood sugar, the sleep apnea. We have become quite good at tackling the comorbid conditions of obesity, but we are not that good at tackling the obesity itself either in terms of treatment or prevention.

Dr Caplan: I want to come back to that, but I want to ask you a slightly personal question. How did you get into this area? Why this area for you?

Dr Korner: I just find it fascinating. My training is as a molecular biologist; from a scientific point of view, I think how we control appetite is extremely fascinating.

Dr Caplan: So it was pure science. You were not someone who was interested in body shape or modeling or fashion in high school or something like that?

Dr Korner: No. I did take a couple of summer night courses in illustration at the Fashion Institute of Technology, here in New York, but that is the extent of my fashion interest. It is really through the science. I also find that working with patients is fascinating. Some things that patients tell me do inspire questions for research. For example, a patient of mine had bariatric surgery, and she told me that she never used to feel full. She would eat and eat until she felt that the food was up to her chin, and it was sort of uncomfortable. She then had surgery, and she could eat many fewer calories and feel full.

Dr Caplan: So remind us: When is bariatric surgery appropriate to think about? When do we start thinking that behavior change is not working, and does the patient need a surgical solution?

Dr Korner: We start off with the most conservative approach. Clearly the cornerstone of weight loss therapy is behavior therapy and lifestyle and nutrition management. If people do not get to where they need to be in terms of their weight, then we may consider drugs. After that, if the drugs are not effective or not effective enough, or if there are contraindications for those drugs, then we move on to the next step, which would be surgery. The idea with surgery is not to help the patient look good in a bikini. The idea of the surgery is to improve your metabolic health. There also may be some psychological and self-esteem issues, but the driver is your health. We do consider the body mass index (BMI) criteria for surgery.

Dr Caplan: When are you as a doctor worried about someone's weight? What is considered fat?

Dr Korner: Well, the definition of obesity is an excess of body fat, which we do not necessarily measure, although we do measure waist circumference.

Dr Caplan: Just waist size?

Dr Korner: Just waist size, and there are parameters for that because the size of your waist reflects your health and your risk for cardiovascular disease. In addition, we use the BMI, which is a number that you can get by plugging in your height and your weight. There are categories of obesity according to BMI.

Dr Caplan: So, 200 pounds in someone who is 6 feet 6 inches tall is not 200 pounds in someone who is 5 feet 1 inch tall.

Dr Korner: Exactly. We use that as a guideline for surgery. We also take into account the overall health of the patient. Two people may have a BMI of 40, which clinically is considered morbid obesity, but one person has diabetes, hypertension, high cholesterol, sleep apnea, osteoarthritis, and the other does not have those issues.

Dr Caplan: But we need to assess both.

Dr Korner: You need to assess both.

Dr Caplan: What do we say to people who see ads on television for quick weight loss? They go to the supplement store. They are swallowing the green coffee beans. What do we say to them?

Dr Korner: This is a huge industry. Much of it is not regulated as we would regulate prescription medications. But you cannot open a magazine without seeing something about weight loss. We have to make sure that the drugs are not dangerous to our patients. Some of these so-called natural supplements have caused strokes, heart attacks, renal failure, liver failure. There will be someone who says, "I took this pill, and I lost weight." Well, it is true that they lost weight, but it may not have anything to do with whatever is in that pill.

Dr Caplan: If they take the pill and exercise more, they may lose weight.

Dr Korner: Right. Or you take a pill, and you are not allowed to eat after 8 o'clock at night or you have to do a 500-calorie liquid cleanse. Again, it probably has nothing to do with the ingredients in the pill, but the patients definitely are changing their behaviors.

Dr Caplan: And they may not be aware that those changes are fueling the weight loss?

Dr Korner: Exactly. In fact, when you look at legitimate weight loss drug studies, they are always randomized and placebo controlled because you will see weight loss even in the placebo group. So you have to be very careful with these supplements. I tell patients what I have just talked to you about, but if a patient believes that the supplement is helping and if I feel it is causing no harm, I let it go.

Dr Caplan: Do you believe a physician or a nurse who is overweight can be a person who works with someone who is trying to battle their own weight? Are they a good role model or do they share the struggle?

Dr Korner: Either way. A patient may see that if you are overweight or obese, then you are struggling and you can identify with the patient. But even a thin physician can provide the right kind of information for the patient. An oncologist does not have to have cancer to treat someone with cancer. That is the way that I look at it.

Dr Caplan: So what do you think is coming down the road? I have heard talk of devices that are the equivalent of pacemakers for the heart, something we might be able to use hormonally. Tell us about that.

Dr Korner: The field is very exciting now, as we start to understand the underpinnings of appetite. We are looking at medications that will target specific appetite regulatory signals as opposed to some general medication that will rev up your system. What I do see on the horizon, as medications have come to the market, is combination therapy. In a sense, that is not surprising. If you look at diabetes or hypertension and many other ailments, one drug is often not enough. You may need a beta-blocker together with a diuretic and an ACE inhibitor. I believe that is how we should look at obesity treatment.

With regard to devices, certainly there is a push to try to come up with some sort of devices like electrical pacing of the stomach, to provide a sense of fullness when people eat. I believe that is being considered. We also are looking at devices that act as a kind of vacuum, to suck food out of the stomach as you eat.

Dr Caplan: I can't wait for that one. In and out. Gives new meaning to "In-N-Out Burger."

Dr Korner: Right. Some devices are trying to mimic some aspects of bariatric surgery, so that you do not have to use laparoscopic surgery; the device is inserted endoscopically, such as balloons or tubes.

Dr Caplan: You are trying to shrink the space in the stomach.

Dr Korner: You are trying to shrink space or reroute the nutrients such that you trigger hormonal changes to decrease appetite. Surprisingly, some of those devices may be useful for the treatment of diabetes, independent of weight loss or in conjunction with weight loss.

Dr Caplan: So it sounds as though some things may be coming down the road to help, but tomorrow, not today. If I am watching this and I have a patient I want to help today, what tips do you have for me? How should I approach the subject?

Dr Korner: Right. The way you broach the topic is very important because if you shame a patient or scare a patient by saying that if you do not lose weight, you will die, that either puts a lot of pressure or a lot of shame on the patient. That patient may not return for another visit, particularly if the patient tried but has not lost weight. We need to be patient with our patients and try to help them come up with a program that is successful for them. Most people would benefit from frequent visits with a dietician; unfortunately, that is not usually covered by insurance, and it can be very expensive. Doctors do not have adequate time to spend with these patients. Recognizing that, we have to help the patients figure out what will work for them. At times, it may mean putting pen to paper and writing a prescription.

Dr Caplan: Or keeping that food diary.

Dr Korner: Yes. We have patients keep food diaries all the time. There are online apps and phone apps you can use. Those are among the most successful ways of losing weight.

Dr Caplan: There is that horrific Fitbit thing. It tells you that you have not gone anywhere.

Dr Korner: Right. It measures number of steps. Lots of different technologies are coming out that we hope will help. Doctors also have to become educated about some of the new weight loss medications. If we did not use a medication when we were training to become doctors and are less familiar with it, we may be less apt to prescribe it.

Dr Caplan: We need to pay attention in this area. New things are coming along. We need to be alert to them. This was very instructive and very useful. I appreciate you sharing your expertise and your time with us.

Dr Korner: My pleasure.

Dr Caplan: I am Art Caplan. Thank you for watching Close-Up.


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