Host: Mignon Fogarty
Transcript: This episode originally aired December 27, 2005
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Mignon: One thing that is really fascinating is that the waist-to-hip ratio is also a very good indicator of the amount of abdominal fat. And what researchers have found just within the last 5 or 10 years is that fat in your abdomen – that abdominal, visceral fat – is different from the rest of the fat in your body. It's actually very metabolically active, which means it is secreting molecules into your system. And they have found that it secretes cytokines, which are inflammatory molecules, that have been implicated in all sorts of diseases including cardiovascular disease. And it wasn't that long ago that researchers thought of fat as a very inert substance. So then to find that fat in different parts of your body have different metabolic activities is very interesting.
Adam: I believe there is a really good correlation between that mid-visceral fat and insulin resistance and type II diabetes. Also a huge extent of mid-visceral fat – that fat that sits in between organs – can, I believe, present a lot of other medical problems as well. Things like surgery can be very difficult in very obese people.
Mignon: That's right. In your abdomen there is still subcutaneous fat that sits under your skin and then there is also that visceral fat that is actually surrounding your organs and secreting those cytokines and that is just very bad.
Adam: Mignon, I remember many years ago when I was doing laboratory research, and doing some surgical procedures on rats. And if you ever saw the inside of an obese rat, it's just very hard to find the organs because they become so buried in all the layers and layers of fat. It looks like an anatomy chart when you are working on lean rats, but when you work on obese rats its just incredible. The best way to describe it is when you get a large box full of packing material and there is a small little present buried deep inside and you have to dig around to find it.
Mignon: Wow, that is probably pretty motivating when you see that.
Adam: Yeah. The organs get buried in all this fat. So you see that and you think, “I think I'll try to keep myself lean if I can.”
Mignon: Well, what's also really interesting is that it's not hopeless.
I had an interesting experience last year. I was working out with a trainer and she told me to do lots of sit ups and I would lose weight around my waist. And I said that's ridiculous, I know you can't spot reduce. And she said, I don't know why but I see it in all my clients.
And she was right, I worked out really hard and I lost about 3 inches around my waist and only about a half inch from my hips. And I just know you can't spot reduce so I went and did research to find out what could be causing this, and I found that just within the last 5 years or so, that when you lose weight through exercise, you preferentially lose that visceral fat around your abdomen. And I don't know if they know why yet, but they are some very interesting studies where they found people who lose weight just through exercise and then just through diet, and then just through diet and exercise. And only the people who lost weight through exercise lost significant amounts of that visceral fat internal that surrounds your organs.
Adam: So more good encouragement to keep yourself active then.
Mignon: Yeah. So that old adage that a calorie is a calorie isn't true. There's more to health than just the sheer energy balance. Exercise has benefits above and beyond what you can do just through diet.
Adam: Certainly. I think there are a number of known benefits from exercise. Some of them aren't proven yet but are theoretical. So exercise with weights helps keep your bone strength, helps keep your muscle mass, which can deteriorate as you get older; aerobic exercise improves your cardiovascular fitness, and then there may be some other benefits because as you do more exercise you may start to increase the number of certain kinds of receptors as you build muscle that help with insulin signaling and there may be some benefits beyond the obvious ones in actually helping to prevent diabetes and obesity because of metabolic changes that happen when you exercise.
Mignon: Boy! I'm going to go exercise when we're done here. I'm itching to get out for a walk.
Adam: But it is also important to remember that exercise absolutely helps, but also you should still remember the caloric balance and remember whatever you take in and don't expend is going to go somewhere.
Mignon: That's right. It doesn't do any good if you burn off 200 calories and eat 400.
Adam: That's right. It's not a license to eat 20 candy bars if you go for a walk.
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