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The Latest Science On Fat And Fitness


This is TALK OF THE NATION. I'm Ari Shapiro, in Washington. Just one week into January, you may be noticing the effects of people's New Year's resolutions. For example, there may be no spots on the treadmill at your gym; no kale on the supermarket shelves. Losing weight is one of the most popular New Year's resolutions and this hour, we'll explore what we've learned in the last year about how some people keep fit, and why others have a hard time dropping pounds.

If you've struggled with weight, and the last year brought a breakthrough for you, what changed? Our number is 1-800-989-8255; our email address is And you can join the conversation at our website. Go to, and click on TALK OF THE NATION.

Later in the program, hashtags on the rise. But first, the latest research on weight loss. Allison Aubrey is NPR's food and health correspondent, and she's with us here in Studio 3A. Nice to have you back, Allison.

ALLISON AUBREY, BYLINE: Hey there, Ari, good to see you.

SHAPIRO: And what did we learn in the last year about weight and weight loss, that we didn't know before?

AUBREY: Well, on a big-picture level, I think a significant thing that's happened is researchers have reported that the obesity rate in the United States has leveled off. We still have an epidemic here; about one in three adults is obese. The rate is slightly higher for women than for men. But clearly, after decades of steady increases, we've hit a plateau.

And with childhood obesity, there was some promising news last year. Researchers have begun to document small declines. Take, for instance, three big cities; in New York, a 5 percent decline in the number of obese schoolchildren was reported - not over a one-year change. That's a five-year change, actually.

SHAPIRO: Uh-huh.

AUBREY: And decreases have also been documented in Philadelphia, and in Los Angeles.

SHAPIRO: America has been trying to fight the problem of overweight - and its health costs - for a long time.

AUBREY: That's right.

SHAPIRO: Is there any indication of what finally got the levels to plateau, or in some cases, drop?

AUBREY: Well, you know, I think experts at the Centers for Disease Control and Prevention, who have been looking at this for a long time, sort of liken it to what happened with tobacco. I mean, the plateau in smoking actually began to take place after - you know, after people had been hearing for years and years about the health risks of smoking.

And it could be that as people hear about the health problems associated with being obese, that we're turning a corner here; that some Americans, or many Americans, may be adopting - if just incrementally - some healthier habits.

SHAPIRO: I've heard it said that people being overweight is the number one public health risk in the United States. What exactly does that mean?

AUBREY: Well, what it means is that when someone becomes obese, their risk of type 2 diabetes, heart disease, some types of cancer and other problems, start to increase. And when you look at this through an economic lens, obesity is linked to - and this is a number I'm pulling out of a study here - $147 billion in weight-related medical bills. Now, that's a 2008 figure, and I'm sure that's grown higher since then. So, you know, experts say if you want to redu - reverse this epidemic, you have to look at some of these diseases that are preventable.

SHAPIRO: OK, so while the health costs of being overweight are real, there was also a recent study that showed the costs of being overweight by a few pounds, may be overstated. Tell us about that.

AUBREY: Well, yeah, you know, I think there's been a little bit of a revision in thinking here. We know that when people are severely obese, that they're going to have a shorter life - or their chances of having a shorter life, having their life cut short because of obesity, is quite high.But new studies suggest that people who are less overweight - now, we're talking about the one-third of Americans who have sort of a pudgy middle or love handles; they fall into the overweight, not obese, category - they actually may live a little bit longer than people who are thin or normal weight. That's actually a new finding.

I have to tell you, it's a very controversial finding, but it's out there.

SHAPIRO: So an extra 10 or 15 pounds may, in fact, be a good thing. But an extra 30 or 50 - no.

AUBREY: Well, when you're looking at longevity. I mean, one of the caveats of this study was, you're putting everybody into two categories. Like, you're putting thin people and normal-weight people into one category, and everybody who's overweight into another. One critic of this study told me, hey, look - when you're looking at this thin category, some people may have ended up in the thin category by virtue of becoming frail and elderly. They may be thin because...

SHAPIRO: Oh, or sick.

AUBREY: ...they're sick, right. And so that might throw it off a bit.

SHAPIRO: So everybody shouldn't go cramming doughnuts just to put on those 10 pounds that will keep them alive longer.

AUBREY: Yeah, that's right. But - I mean, at the same time, there is evidence that there are people who are fit yet fat. You know, they are cardiovascularly, in good shape yet still hang on to a little extra weight. I mean, let's face it - we're not all going to be tall and thin. Genotype decides a lot. And you know, we all look a little different.

SHAPIRO: Let's talk about efforts to lose weight.


SHAPIRO: What do we know now that we didn't know before, about what's effective?

AUBREY: Well, I think that what's happened is that over the years - it's funny; if you look back at diet studies from, say, five, 10 years ago, you would often see like, head to head. Is the Atkins diet or a low-carb diet better than a, you know, low - you know, low-fat diet better than an Atkins diet? Blah, blah, blah. The answer to that question ended up being, you know, any diet is good if you stick with it.


AUBREY: So the question, in recent years, has become well, how do you stick with it - right?


AUBREY: And what the research community now knows is that there are sort of three things involved with successful dieting. First, you have to know which diet plan you're following - how many calories you're supposed to be eating, what you're supposed to be eating, right? After that, group support is very important. And the third thing - and this is perhaps the newest part of the equation here - is the idea of logging what you eat; keeping track of it. Research suggests that when you're keeping a log of everything you eat, it helps to reinforce sort of daily self-control. And with these new smartphone apps that give you instant feedback about what you're tracking - they'll say, hey, you've had 200 of your 2,000 calories; or you've, you know, logged, you've jogged one mile of your goal today - that helps as well. So it gives you real-time...

SHAPIRO: So technology has really given new opportunities to lose weight...

AUBREY: Well, you know, it's been a question - and researchers at Northwestern University actually published a study about this just a couple of months ago, where they looked at whether a mobile app could help. And they found that the mobile app was actually very successful if it was used as part of this comprehensive strategy of, you know, knowing what you're supposed to be eating, and having some sort of group support, yeah.

SHAPIRO: Group support, yeah. Let's take a call from Armando(ph) in San Antonio, Texas. Hi Armando.

ARMANDO: Hi, how are you all doing?

SHAPIRO: Good. Tell us your story.

ARMANDO: Well, basically, I lost about 40 pounds a little bit over a year ago. My cholesterol level was so high that I had a hard time staying awake. I have kids - a 3-year-old, 11, 10 - and my wife noticed that, well, Daddy wasn't as active. And I couldn't be because my body just wanted to shut down. So we went to the doctor, and she and I both realized we needed to lose weight. And not only that, but we needed to live a healthier lifestyle and change a lot of what we ate and drank.

SHAPIRO: So you say you lost 40 pounds. How did you do it, and were you able to keep it off?

ARMANDO: I've been able to keep most of it off, except for about 10 pounds. But I'm going back. And it has a lot to do with portion control, cutting sugar almost completely off; just developing a new culture of eating - going and buying products that are basically low calorie, no sugar, staying away from the artificial sweeteners; also, getting my kids involved, helping them...

SHAPIRO: And that sort of speaks to what Allison Aubrey was just discussing, about having sort of a social group support in the effort.

ARMANDO: Very important.

AUBREY: And you actually said something really interesting just then. You said a new culture of eating. And one thing that I think is really fascinating is just yesterday, I reported on a new study that found that far fewer Americans are on a, quote, diet; or were on a, quote, diet in the year 2012, compared to years past. And you may scratch your head when you hear that because yes, we're all still, as a culture, interested in being thin and being healthy. So I don't think it's that people have given up on their goals. But I think the term "dieting," to some extent, and the philosophy, to some extent, has become a little passe. I mean, I think the new buzzword, rather than diet - which seems to suggest, you know, restriction or alternating between complete indulgence and complete denial - the new buzzword, I really think, is lifestyle change.

And so you hit on it when you said - sort of - new culture of eating. It's not about a prescriptive diet as much as it is about a pattern of eating and exercise habits.

SHAPIRO: I want to bring another voice into the conversation. This is Dr. Timothy Church, who is a professor of preventative medicine at the Pennington Biomedical Research Center at Louisiana State University. He studies the effects of obesity, weight loss and exercise on health. He joins us now by smartphone, from his office in Baton Rouge, Louisiana. Thanks for joining us.

TIMOTHY CHURCH: Oh, thank you.

SHAPIRO: And Dr. Church, we've seen a lot of change in obesity research. Tell us what we know now, that we didn't know before.

CHURCH: It was really - it was a huge year before that paper came out just a few weeks ago, on BMI. But I...

SHAPIRO: On body mass index.

CHURCH: Yeah, body mass index, and in some of the resetting the categories - which I think, actually, are really important. But to me, the two big areas that - is one, the medications. For the first time in whatever it is - 14 years - the FDA has approved new medications for weight loss. The two that have been approved, look to be very effective. This is important - they're important for two reasons. One is, it gives clinicians another tool in the toolbox, which is so desperately needed in the clinical setting. And two, these drugs are not just about weight. They're about changing - having healthy metabolic changes with the weight loss. It's about preventing diabetes; it's about reducing your blood pressure; it's about improving your cholesterol profiles.

SHAPIRO: But these are not "I need to lose 10 pounds, so I'll take a pill" kind of drugs.

CHURCH: Exactly. They're for people who medically, need to lose weight. They're A, overweight; B, they more than likely have a medical problem that's associated with the weight - pre-diabetes, hypertension or cholesterol abnormality. And that - it's a new way of thinking. It's the idea of treating excess weight - and we're talking about obesity here; class I, II and III - treating excess weight like a chronic disease...

SHAPIRO: So these are people...

CHURCH: ...not a vanity issue, a chronic disease.

SHAPIRO: So these are people who might be eligible for bariatric surgery, or having a stomach-staple; something like...

CHURCH: A lot - most of the people who will benefit from this are not in that bariatric surgery range yet. We've had - we know lifestyle works. We know bariatric surgery works. We've had this big gap in the middle where, you know, they kind of - clearly, the lifestyle would benefit them, but it wasn't going to produce substantial amounts of weight loss. And that's where these medications fit in, right in that gap; in the people who are kind of class I, class II obese; who are right on the edge of really bad health things. And you bring in a medication that can produce like, 10 percent weight loss, and you're going to get a lot of health benefit associated with it.

And you mentioned surgery. I want to bring that up. You know, there's a lot of surgeries done in this country, and there's not nearly as much research as you would think. And this year, we filled in a lot more pieces of the puzzle, particularly related to the role of bariatric surgery in diabetes. It is very clear that in individuals with diabetes, bariatric surgery can have tremendous benefit. And you can argue this point, but it comes pretty darn close to reversing diabetes in the majority of individuals. And diabetes, of course, leads to so many other bad things, whether it's kidney failures or heart attacks, strokes...

SHAPIRO: All right. Dr. Church, stay with us. We need to take a short break, and we're going to be right back. My guests are Dr. Timothy Church and Allison Aubrey, who is food and health correspondent for NPR. If you've struggled with your weight but then had a breakthrough in the last year, tell us what changed. The number is 1-800-989-8255. Or you can send us an email, Stay with us. I'm Ari Shapiro, and this is TALK OF THE NATION from NPR News.


SHAPIRO: This is TALK OF THE NATION from NPR News. I'm Ari Shapiro. Recently, The New York Times revisited the story of Elsie Scheel. One hundred years ago, when she was 24 years old, the Times ran a profile of her, describing her as the epitome of perfect health. She was an active, athletic woman; fond of a, quote," good, bracing tramp." And she enjoyed eating beefsteak, according to the Times.

She also had, at the time, a body mass index of 27, which by today's standards is considered overweight. Her story is a great example of what we're talking about today - what we know about health and weight, and how it's changing. So if you've struggled with your weight but had a breakthrough in the last year, we want to know what changed. Our number is 1-800-989-8255; our email address is And you can join the conversation at our website. Go to, and click on TALK OF THE NATION.

My guests are Allison Aubrey, food and health correspondent for NPR; and Dr. Timothy Church, professor of preventative medicine at Louisiana State University. Let's take a call from Linda in Myrtle Beach, South Carolina. Hi, Linda, go ahead.

LINDA: Hi, thank you so much, Ari; great show. I had to have surgery for knee replacement, and I had an old injury to my femur from years back, that had to be repaired. And I was sadly overweight. And I realized that through the pre-op testing and everything, you know, my blood sugars were running high; my cholesterol was running high. And you know, I'm a pretty young grandma. And I said, you know what? I need to be around. I need a real reality check here. And so I had this surgery - I had the knee replacement - and everything went well. And little by little, it just got more and more important.

You know, in your 20s and 30s, you want to look sexy, and you want to be beautiful. I think you reach a certain age where you know that you have to be healthy. And your mortality kind of hangs above your head, a little bit. And so for me, that's really what did it. I'm now 20 pounds down. But I'm going to Weight Watchers, which is a wonderful program because people like to eat.

And that's the other thing I wanted to mention. The whole component about losing weight for health reasons, or whatever your reasons are, is wonderful. But we also need to look - and examine the reasons why people overeat. There's a whole emotional component to it. And I really think the medical field doesn't do a really good job of addressing that.


LINDA: You know, they offer all these programs; and they offer surgery, which is successful. But how many people do you see that have that, and the weight creeps back on them? How many people drop...

SHAPIRO: That's a great point, Linda. Yeah...

LINDA: ... you know, 40 or 50 pounds, and then it creeps back up. So I would love to hear some comments from the panel today about how that might be addressed.

SHAPIRO: That's a great point, Linda, thanks for the call. And Dr. Church, you know, as she says, there is the medical component and also, the psychological component. Eating is culture. Eating is family. Eating is friend. Eating can be soothing. How do you deal with all of that, as a doctor whose practice is medicine?

CHURCH: Oh, it's mind-bogglingly complex, you know. And that's part of - that's part of - you know, one of the things I didn't mention is, we're getting better and better at the behavioral side of things; of training people, to give people the skills to make the right decisions when it comes to eating. And part of behavioral skill training is helping people assess why they eat. You know, are you a stress eater? Are you eating for comfort?

And when you help people identify why they eat - you individualize it - then you can teach them strategies to deal with it. And Linda brought up a great point. I want to go back to her previous point, about quality of life and the knee. And that's so important because modern medicine is going to get most of us to the age we're supposed to get to, but it doesn't guarantee us the quality of life we want. And being physically active, eating healthy, that helps promote the quality of life that we're all going to be looking for so we can play with our grandkids, just like Linda talked about.

SHAPIRO: We have an email here from Isa(ph), who writes: My whole life, I thought calorie counting was silly and obsessive; and that the only way to stay at a healthy weight was by frequent exercise and healthy food. When I got pregnant with my first child this year, however, I learned the hard way that no matter how healthy you eat, overeating will increase your weight. I gained 55 pounds during my pregnancy, twice what's recommended for someone of my stature. After giving birth, I was determined to lose the weight as soon as I could. I began by counting calories, which made me realize how much I'd been overeating my whole life.

Allison Aubrey, as we talk about counting calories...


SHAPIRO: ... many restaurants, in the last year, started posting calorie counts.

AUBREY: That's right, yeah.

SHAPIRO: What impact, if any, has that had?

AUBREY: Well, you know, I think it's probably too soon to say. We'll see more posting of calories, in the months to come. There's actually a little...

SHAPIRO: This was part of the Obamacare - health care bill...

AUBREY: That's right, a little provision in the health care bill. And McDonald's was an early mover on this. They started posting calories just this past fall. And what we know so far, is this: When people know how many calories they're supposed to be eating, when they know how to count calories, then calorie boards are really effective - because they're paying attention. But this is a really small percentage of our population, unfortunately. So I think that in order for calorie boards to have some success, or to make a difference, there has to be an education component, too. People have to know how to count calories, and how many they're supposed to be eating.

SHAPIRO: So knowing that they're consuming 500 calories is only relevant if they know that they're supposed to have 2,000 total.

AUBREY: That's exactly right, that's right.

SHAPIRO: Let's take another call from John(ph) in Moscow, Idaho. Hi, John.

JOHN: Hi, how's it going?

SHAPIRO: Good, tell us your story.

JOHN: So I'm an alumni of a fraternity here. And right now, I'm going to grad school. And my story is, basically, a fraternity brother of mine and myself, we're kind of getting overweight. Actually, we're getting quite overweight. And we just kind of woke up one day, looked at each other; and we were like, you know, how did we get this big? And I weighed 275 at the time. He was shorter than me, but he weighed - I don't know, I think around 240. And then...

SHAPIRO: So what did you do?

JOHN: Well, I - the funny thing is, we had an older brother who was an alumni, who is - he had gotten hired by the WSU Cougar football team as a strength-training coach.

SHAPIRO: So you went to strength training?

JOHN: Yeah, and - well, and the thing is, he had a nutrition degree from Texas Tech, where he - or Texas - University of Texas.

SHAPIRO: And what was the most helpful thing that he taught you?

JOHN: So the biggest thing he taught me was to kind of cut back on some of the things like beer and cheese and fats, and stuff. And he said - you know, really, diet is number one. But you can't, you can't really lose weight without exercise...


JOHN: ...but diet is the biggest deal.

SHAPIRO: OK, well...

JOHN: He said - he had this thing he always used to say; was that it's a simple equation of burn more calories than you eat, and you'll lose weight.

SHAPIRO: Yeah, thanks for the call, John. In some cases, clearly easier said than done. But Dr. Church, do people always appreciate the number of calories that are in alcohol, or is that sort of like a hidden weight-gainer?

CHURCH: No, great point. You know, especially men, I tell them that all the time. I say, you want to start losing some easy weight? Evaluate your alcohol calories. There was a real nice paper looking at that, this year. I mean, there's multiple things with alcohol. A, there's a lot of calories in it; B, you drink a few and suddenly, you're eating more that you normally wouldn't eat. You know, that's always an easy place to start.

SHAPIRO: Allison Aubrey, people talk a lot about diet, and they talk a lot about exercise. There is a third element here that blew my mind that is completely relevant to how much a person weighs.


SHAPIRO: Here's the big reveal; go for it.

AUBREY: Well, it has to do with the amount of shut-eye you're getting.


AUBREY: Sleep, sleep. Yeah, you know, for a while now, we have known that shift workers, people - let's say overnight nurses, working in the hospital - are at higher risk of gaining weight than their colleagues who are working the day shift. And the question has always been, well, why are shift workers at risk of gaining weight? Is it because they're up more hours of the day, they just have more opportunity to eat; or is it something else?

And there have been hints, for a couple of years now, that it actually goes to some basic biology. For instance, a paper published this year shed a lot of light on what's happening in the body. Let me tell you about it. Researchers at the University of Chicago recruited a bunch of young, healthy people in their 20s who were not overweight. They put them in a sleep lab for four or five nights; let them sleep a full night's sleep - about eight or eight and a half hours, or so; took a sample of their fat - took a fat cell sample. A month later, they brought these same subjects back. They let them sleep - they deprived them of sleep; let them sleep maybe four, four and a half hours a night, which is clearly, not enough,

And what they found is that in that short period of time, these healthy adults became insulin-resistant. And what this means is, over a long period of time, you know, you're setting yourself up for type 2 diabetes, fatty liver disease, weight gain. What's happening in the body is that the body is seeing this lack of sleep - is doing something completely different. The body is basically saying, I am completely thrown off here. And over the long term, a lack of sleep is basically read by the body as danger. And when the body feels in danger, what does it do? The body stores fat.

SHAPIRO: This is mind-blowing to me. So Dr. Christo(ph), if someone has an option of getting not enough sleep so that they can get to the gym and exercise; or getting a full night's sleep, which apparently keeps people thin; it sounds like they're damned if they do, and damned if they don't.

CHURCH: No, I don't think so. I mean, most people are not sleeping because other issues are going on in their life. I mean, the easy answer to your question would be, go to bed earlier. But you know, you bring up another - and when do you exercise? I get that all the time; should I exercise before work, at lunch, or after work? I say, whatever's best for you. You know, it's the same thing with diet, same thing with exercise. It's key to figure out who you are, and what you like to do - and do that.


CHURCH: I hear all the time, well, I don't like to run, so I don't exercise. Then do something other than running. And, you know - so that wasn't directly answering your question, but it was...

SHAPIRO: But you do what works for you.

CHURCH: You do what works for you.

SHAPIRO: We have an email from Sharon, who writes: A year ago, my husband gave me an iPad for Christmas and several months later, I realized that I'd been losing weight without trying. In fact, I thought maybe I'd been eating more; including nice dinners out, rich foods, desserts even - than usual. I even became a little concerned that maybe I had a medical problem, but didn't have any symptoms. The only change I could figure out - she writes - was that instead of going upstairs to sit at my PC after dinner, in the evenings, I was now standing up at the kitchen counter, where I keep my iPad. I am now convinced that standing up more is the answer.

Allison Aubrey, is it the answer?

AUBREY: (LAUGHTER) Oh, well, you know, I think the best headline of 2012 was - a story that read: "Why Sitting All Day Will Kill You." Honestly. This was a real study.

SHAPIRO: (LAUGHTER) I'm going to stand up on my chair right now.

AUBREY: Yeah, yeah. Right, right. We both should. We should bring like, a little - you know, treadmill in here. Researchers estimated that sitting more than six hours per day - now get this - makes you 40 percent - I'm reading here - more likely to die within 15 years, compared to someone who sits less than three hours a day.


AUBREY: Now, this is hard to get your mind around, right? I mean, what if you start sitting when you're age 90?

SHAPIRO: Right, right, right.

AUBREY: But of course, your - and your longevity, of course, depends on other factors, too. But these kinds of studies catch our attention because a lot of us know that we sit too much, and we know that being sedentary is risky.

SHAPIRO: All right. Let's take another call; from Andrew in Honolulu. Hi, Andrew.


SHAPIRO: Go ahead.

ANDREW: Glad to be on. I was - I'll try and make it quick. There were two things that my wife and I used, over the last year. I was up at about 260. My BMI was in the 30s. My wife was up at 200, and she's only 5 foot 2. And that was mainly from pregnancy, but we both figured we needed to lose weight. So it was an iPhone app...


ANDREW: ...and you guys had talked on it earlier, but I do want to plug it. It's called MyFitnessPal, and it's a tremendously good app. It...

SHAPIRO: And what does it do, specifically? Is it counting your number of steps, calories?

ANDREW: Well, it - you - well, your - you put in your information so that it does all the calculating of your height, your weight, all those things; to give you kind of what a healthy number of calories you should be taking in. And you can assign whether you want to lose half a pound a week, up to 2 pounds a week, you know? And then you follow that, and you enter everything you're eating.


ANDREW: And by doing that, it keeps track for you. And with my wife and I, it allowed us to communicate via this iCloud-type of world so we could watch each other, and hold each other accountable.

SHAPIRO: So you're sort of pointing to two of the things that Allison mentioned as being one of - two of the three keys to successful weight loss, which is...

ANDREW: Exactly.

SHAPIRO: ...tracking, and support from others. Well...

ANDREW: Exactly, and this app really does it for you. The other...

SHAPIRO: Thanks for the call, Andrew. Oh...

ANDREW: Well, the other thing that helped us - and I plug products just because they work - the Wii Fit. You know, unlike a regular scale...

SHAPIRO: Oh. Standing in your living room, playing tennis.

ANDREW: Yeah. No. Moreover, it has a body, where you do a body - you know, you stand there, you do your thing, and it weighs you, and it...


ANDREW: ...checks all these things. And you enter all your information into it, too. And it also keeps you accountable. And unlike a regular scale, it tracks it for you, and...


ANDREW: logs it. And so you're visually following everything.

SHAPIRO: OK. Thanks for the call, Andrew. We're talking about what works in weight loss and what the science has told us, in the last year. You're listening to TALK OF THE NATION, from NPR News. Here's another call - from Devin(ph) in Los Angeles. Hi, Devin.

DEVIN: Hi. I'm actually calling because I was listening in on - there's an - I actually have a longstanding history of excessive weight within my own self, and as a kid I developed some bad health problems. The way they treated it, in the early '80s, was large and prolonged doses of steroids; and of course, that doesn't help anybody. But over time, it developed to this point where it was almost impossible for me to physically lose weight. And it came to a head, to where I ended up having to look seriously at bariatric surgery.

SHAPIRO: Hmm. Did you go that route?

DEVIN: What was that?

SHAPIRO: And did you ultimately go that route?

DEVIN: I did. And after looking at various, different options of that, I chose the one that I felt was sort of the least invasive, and the least troublesome. And it actually helps. It is not a cure-all. And I think that's kind of a misnomer for a lot of these pills that the FDA is recently approving; a lot of products like, say, Alli or Sensa, or what have you; even the whole bariatric surgery route. There is - there seems to be an assumption amongst a lot of the population that this will cure all of my problems. It doesn't.

SHAPIRO: But there are behavior changes that have to take place as well.

DEVIN: Huge behavior changes. And...


DEVIN: And it was never a big issue for me to change my diet. I've never been an unhealthy eater. But when you realize, all of a sudden, you're going from, oh, you can eat whatever you want; to your stomach's literally left a third of the size it used to always be...

SHAPIRO: You just have to behave differently. OK. Thanks for the call, Devin. I appreciate it. You know, in a couple minutes that we have left, Allison, we haven't yet talked about what the science has told us in the last year about exercise, and what we know now that works.

AUBREY: Mmm. Well, you know, I think that a big question for a lot of people is, how do you get the most bang for the buck - right?


AUBREY: We don't always have 90 minutes to exercise. And this is something where there have been some lovely studies this year, and it goes back even three or four years ago. We started to hear about the importance - or the success you can have when you do what's called interval training. I'll just tell you...

SHAPIRO: Explain what that is.

AUBREY: Well, in brief, it's the idea - you know, I don't know if you've ever done any kind of cycling class, where you - or spinning class, where you kind of slow-pedal for a little bit; and then you fast-pedal for a little bit. And you sort of alternate the speed, or the intensity, that your...

SHAPIRO: Right. So you go your maximum capacity and then...

AUBREY: That's right. That's exactly right. And so the idea of an - interval training is that you kind of, you know, rev it up to your full potential, and then sort of dial back a little bit.


AUBREY: And a study done in Australia - they put a bunch of middle-aged people on bicycles. These were people who were not fit. And they were overweight, and they said, hey, OK, we want you to pedal slowly for 12 seconds, and then pedal quickly for eight seconds. And they do this for about 20 minutes. And over the course of four months, these people lost about six pounds; which was significantly more than the people who were just slowly pedaling along. And it sort of speaks to this idea that when you do interval training, you can sometimes get in shape more quickly, and there's sort of a little more bang for the buck.

SHAPIRO: Even if you have only a few minutes to do it. And Dr. Timothy Church, last thoughts about what we've learned about exercise and what works, in the last year.

CHURCH: You know, I think Allison hit on it. It's the idea of variation, and what works for you. She mentioned interval training, and I would throw out there weightlifting. You know, as we age, we lose 1 to 2 percent of muscle mass from - kind of age 40, on. We're seeing, more and more, the importance of lifting weights - functional weights, and the role it plays in quality of life.

SHAPIRO: Great. That's Dr. Timothy Church, professor of preventative medicine at the Pennington Biomedical Research Center at Louisiana State University. He joined us by phone from his office in Baton Rouge. Thank you for your time.

CHURCH: Oh, thank you.

SHAPIRO: And here at Studio 3A, we have Allison Aubrey, food and health correspondent for NPR. Thanks for being here, Allison.

AUBREY: Thanks, Ari. It's been fun.

SHAPIRO: When we come back, we'll talk hashtags. They are all over your Twitter feed, and creeping into everyday conversation. Some people are still unclear on just what they're for. We'll get some clarity after a short break. Stay with us. I'm Ari Shapiro. It's TALK OF THE NATION, from NPR News. Transcript provided by NPR, Copyright NPR.