Story transcripts

The Fat Gene

Thursday, April 5, 2012

Reporter: Liam Bartlett
Producer: Howard Sacre

It's the curse of every dieter. Shed a few kilos. Then pile them all back on again.

We've always blamed ourselves; we should have kept up with the exercise, shown more self-control. But Australian Idol winner Casey Donovan (pictured) is one of thousands of Australians to suspect her weight is about more than just food.

In fact, researchers in Melbourne have come up with another more "palatable" explanation.

They're discovered that a person's weight is predestined, that genetically your body will fight to put the weight back on again.

All without you even knowing about it.

There is some good news though: the new findings are turning the science of weight loss on its head.

Story contacts:

The University of Melbourne, Sir Edward Dunlop Clinical Research Unit
T: +61 3 9496 2250

Full transcript:

LIAM BARTLETT: The big voice has been a blessing, but the big body has caused years of anguish for Casey Donovan. How hard have you tried over the years to lose weight?

CASEY: Oh, look – I’ve tried extremely hard. I’ve gone ON all the fad diets and had all the good trainers, the great trainers and you know, I’ve learnt so much I could probably be a trainer and dietician myself. But in the end, you kind of just go, “oh, well I’m back where I started.”

LIAM BARTLETT: Casey’s career got a spectacular start when she won Australian Idol in 2004. What we didn’t know then was how much her oversized frame was tormenting her.

CASEY: Looking back at what and how I was on Idol I thought, “God I wasn’t big at all. I would have been a size 18.” I was like, “wow and I still got crapped on for being that size at 16.” Great.

LIAM BARTLETT: I don’t want to be rude but what weight were you at your heaviest?

CASEY: God, I would have been about 22 and I was weighing in at about 155, close to 160 and…


CASEY: Kilos, yep and I was just at that point in my life where I was like, “what have you done?”

LIAM BARTLETT: A lot of us know that feeling very well but why does it happen? To try to answer that, a group of 50 overweight Australians were enrolled in a special study. They were put on a 10-week, very strict, low-energy diet and they lost a lot of weight. They then returned to normal eating – with a lot of advice about what to eat and how to exercise. But slowly those kilos they’d tried so hard to lose went back on again.

KATRINA: This study has shown that it’s not simply a matter of them being lazy and not being able to keep the weight off, that their body is actually wanting them to get to back to the old weight so they have to keep just being hungry. They will be hungry.

LIAM BARTLETT: Dietician Katrina Purcell and her colleagues discovered that the 50 dieters didn’t just undergo dramatic changes to their waist lines – their hormones went totally haywire. One in particular, the so-called “hunger hormone”, or ghrelin, ran riot when they went on a diet. It jumped by an incredible 20% – and kept telling the body that it was starving, long after the diet stopped.

LIAM BARTLETT: Your study is saying this is a biological thing? A chemical thing going on in the body – it’s not just about the body wanting food?

KATRINA: Yeah, I’m saying it’s a physiological thing so it’s a biological drive that makes you want to put the weight back on.

LIAM BARTLETT: Yeah, it’s not just about you wanting to have a late-night snack.

KATRINA: No, not at all.

LIAM BARTLETT: Vincent Butler, who’s taking part in the study, is the perfect example of someone who is motivated to get into shape, but just can’t.

VINCENT: It’s the keeping it off that’s the hard bit. I’m not weak-willed. I’m not deficient in any way, mentally or physically. There’s no sickness, it’s just that my body’s inclination is to be big.

LIAM BARTLETT: In fact, the body has a genetic mind all of its own. The Melbourne University team, led by Professor Joe Proietto, has discovered that our bodies gravitate to a predetermined weight. And it’s written in our DNA.

JOE: There is a set point – which is probably genetically determined – that is defended by the brain. So you can make a decision with the conscious part of your brain that you don’t want to be that weight, but your subconscious has other ideas. It’s following its program, which says you need to be a certain weight.

LIAM BARTLETT: So they got all that advice and that guidance and they just what? Couldn’t help themselves.

JOE: Correct. Now, if you want to know how they feel, I urge you to not eat for two days and then see how you feel when you walk in your kitchen.

LIAM BARTLETT: Casey Donovan battled the bulge every which way until three years ago – when she made a life-changing decision. She gave up crash diets, decided to feel positive about her weight and launched her Big, Beautiful and Sexy tour.

LIAM BARTLETT: This science must give some solace though, to big people like yourself – “don’t judge me, it’s not really my fault”?

CASEY: Yeah and that’s the thing like a lot of people see big people on the street and see me and kind of go, “oh you’re big, you must eat McDonalds and KFC and Hungry Jacks and all this shit every day.” And you go, you know what, “I don’t sit at home just shoving my face full of food.” I’m always on the go and like most other big beautiful and sexy people, they’re on the go. I’ve learned to love myself and it’s taken a good eight, maybe even ten years to kind of go, “you know what Casey? You are always going to be the bigger girl in that room or you’re always going to be the bigger girl lining up to get something to eat so don’t think about it. Don’t stress about it. You are who you are so be proud of it.”

LIAM BARTLETT: The bottom line of this new science of weight loss is pretty harsh – fat people, despite their best efforts, will probably stay fat and there’s really not a lot they can do about it. Not everyone agrees though. Over in the US, there’s a very active group of successful dieters who believe the Melbourne study is sending out all the wrong signals.

RENA: The Melbourne study was a very small study and I think that’s a very pessimistic message for viewers and listeners to hear because we know that many people are able to be successful at weight loss and so…

LIAM BARTLETT: It may be pessimistic but is it reality?

RENA: Ah, I don’t think it is.

LIAM BARTLETT: Dr Rena Wing from Brown University Medical School in Rhode Island is doing a much larger study – of 10,000 dieters – and she reports a very different outcome.

RENA: On average they’ve lost about 30 kilograms and they’ve kept it off about six years. One of the interesting things is that they report that they have tried many times before to lose weight unsuccessfully but this time they got it right okay.

LIAM BARTLETT: So what was the difference?

RENA: What they say is “this time I was more committed to behaviour change and this time physical activity was a bigger part of my regimen than it was in other approaches.”

LIAM BARTLETT: By “physical activity”, she means a lot of walking – at least 45km a week. Lynn Haraldson used to be 136 kilos – then dieted down to 63 kilos. But to stay there, she’s – to use her words – “hyper-vigilant.” Do you have to weigh your food everyday?

LYNN: Yeah, I still have to weigh things but I can pretty much eyeball things now. I’ve gotten so used to it. There are times when I’m making an omelette and usually my omelettes are made with three egg whites but then there’s a part of me that will go, “Well Lynn, you know you worked out today. Put a little extra, put a whole egg in there if you want.” It’s an extra 70 calories right there you know and I need to be vigilant about that.

LIAM BARTLETT: 70 calories.

LYNN: Yeah, just or you know or anything like that, just to add those types of…

LIAM BARTLETT: You’ve got those measurements right there?

LYNN: Yep. Yep, well I said after seven years, you get real good at it.

LIAM BARTLETT: But that’s not normal is it – watching what you eat all the time and doing that amount of exercise?

LYNN: Well you see that’s the question. I mean it’s sort of what is normal? Is it the behaviour that we’ve now created in the United States and Australia where people come into their office, sit all day at their office, go home and eat these gigantic meals, eat between meals all the time? We used to be very physically active. People were working in farms or in factories being very physically active. Is it so abnormal to do an hour of physical activity a day? Maybe it’s not, maybe it’s abnormal given where we are now but that’s why we have this obesity problem.

JOE: What she describes is obsessive-compulsive behaviour. These people weigh themselves every day and run marathons. What do you think they are?

LIAM BARTLETT: So if we’re not completely obsessive, we’re just leading a normal life, we’ll probably put the weight back on?

JOE: Yep, tep. And that’s certainly explains the experience of all of us who treat obesity – that it’s a difficult thing. Not so much to get the weight off but the failure rate after a few years is very, very high.

LIAM BARTLETT: The scientists do agree on some things – that a good, balanced diet is vital to our health. And that we spend far too much money and effort on diets when the real need is to keeping the kilos off once we’ve lost them. Do you have to watch what you eat now carefully?

CASEY: Oh, look – you know, I still watch what I eat but not as careful as you know, some. Splurge but always make sure – for me, if I’m going to splurge I’ll make it up during the week and you know, go for a double swim and you know feel good. You can still be good, eat good, eat crappy sometimes but be healthy.

JOE: Everybody tells the fat people that it’s their own fault and they not only they believe it. They believe it. And I like to think that our study shows the way forward in ways of being able to help these people.

LIAM BARTLETT: These days, Casey Donovan sings proudly. So much so, she performs a special tribute show to Mama Cass – the portly American artist from the 60s and 70s, almost as famous for her morbid obesity as she was for her music.

CASEY: She was that voluptuous lady that I heard lots of stories of boys throwing their room keys on the stage for her, so go Mamma Cass.

LIAM BARTLETT: Finally, Casey Donovan is comfortable in her own skin.

CASEY: It’s good to have you know, a reason why – not an excuse because we’re not getting out of it that easily – but you know, a nice reason why our bodies are like this and still live to have fun.

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