‘What Happens Next?’: Why Is It So Hard to Lose Weight?

Dr Susan Carland: Welcome back to What Happens Next?, the podcast that examines some of the biggest challenges facing our world and asks the experts, what will happen if we don't change, and what can we do to create a better future?

I'm Dr Susan Carland. Keep listening to find out what happens next.

Michelle Bridges: We've seen almost what you would call a tsunami of obesity in the last 30 years. Dr Ahmad Aly: The community, society at large, hasn't quite kept up with where the science is.

Dr Hilary Offman: It's absolutely one of the most legitimate forms of discrimination.

Dr Michael Cowley: And I think we haven't explored the changes we can make to our environment to help facilitate better weight control.

Dr Susan Carland: Despite the miracle diets on Instagram and the weight loss clickbait we see all over the internet these days, anyone who's ever tried to lose even a bit of weight can agree that it's hard. Really, really hard.

And the way we've been taught to think about it isn't helping. You can swear by an easy, calorie-in, calorie-out formula all day long, but for some people that doesn't seem to make a difference at all. And even the way we talk about bodies and fat is fraught.

As new evidence emerges, we seem to be expecting the impossible of our own bodies and others. What does science really have to say about weight loss? Should we change how we think about – and therefore talk about – diet, exercise, and wellness?

Welcome to part one of our look into weight loss on What Happens Next?.

Dr Michael Cowley: So, it's hard to lose weight and it's really hard to keep it off.

Dr Susan Carland: Professor Michael Cowley is head of Monash University's Department of Physiology, and was the founding director of the Monash Obesity and Diabetes Institute.

Dr Michael Cowley: The clinical data suggests only about 20 per cent of people who lose weight can keep it off. But we know most people can lose weight, or at least a little bit, early, but very few keep it off. One in five keep it off.

Dr Susan Carland: And when you say one in five can keep it off, what timeframe do we consider keeping it off to mean? Dr Michael Cowley: Yeah, that's about five years out.

Dr Susan Carland: Right. Okay.

Dr Michael Cowley: And so, one would assume that 10 years out, even less than that proportion would be weight-reduced.

Dr Susan Carland: And what happens to the other 80 per cent? They lose weight and then they gain it back?

Dr Michael Cowley: Yeah, they just regain it. And it happens over varying time courses. One of the most damaging conditions we see is people who repeatedly lose weight and regain it, and lose weight and regain it. And there's good suggestions that when you do that, your body changes fundamentally and becomes much more energy efficient, and so you require less food intake to keep yourself weight stable, which means that to keep weight off, you have to food-restrict yourself even more.

And so, for example, the people who participate in those TV shows where you lose weight, at the end of that process, some of them have had dramatic changes in the way their body handles energy, and so they are predisposed to weight regain. But if you've done it three or four times, then the predisposition becomes worse and worse.

Dr Susan Carland: It's like the body fights back.

Dr Michael Cowley: Exactly.

Dr Susan Carland: And is determined to bring you back to the weight that you were.

Dr Michael Cowley: Absolutely. And we see it both with weight gain and weight loss. So, the body fights to not gain weight, because the brain helps us balance our body weight, restricting how much we gain. And the flip side's true, too. When people decrease their food intake, they don't lose as much weight as those calories would suggest, because the body becomes more energy-efficient. And so, the brain fights against changes in our body weight.

Dr Susan Carland: So, it's like every person has something of a set point.

Dr Michael Cowley: Yeah. We call it a set point, but I think we can put too much emphasis in that set point because it's not really hard encoded. It's a response to our environment. And some people call it a settling point, because with a given level of other activities in your life, that set point will fall at different places.

So, you might have a set point with a certain level of activity, but if you double your activity, then that settling point will be at a lower weight. It's just that we live in a world where we don't need to do very much, and for many people, exercise requires not just a conscious effort, but an expenditure of money, because of the built environment we live in makes those things more challenging than they were in our evolutionary history.

Dr Susan Carland: Michelle Bridges is Australia's most influential personal trainer. You probably know her from the hit reality television show The Biggest Loser. She's also the author of 17 bestselling books on fitness, nutrition, and mindset. I wanted to ask her, what are the contributing factors that make it difficult for her clients to keep weight off? It turns out there are many.

Michelle Bridges: Yeah. Well, a lot of people will say that keeping it off is harder than the initial getting it off in the first place. I mean, I've heard that many, many times, and witnessed it with many of the people that I've worked with as well.

It is a very complex can of worms when you start looking at it, because not only do we have to consider our DNA, our gene pool, where we come from, our culture, our genetics, our gender, our age, our hormones, whether or not we're taking medications, our past traumas.

I know it sounds like a lot, but these are the complexities that kind of weave their way into often why people struggle to keep their weight off. I've had many instances where people will say, “Well, something happened. I had a death in the family. Or I've just got stress, or I've lost my job, or I've had an injury.” And these are the reason as to why they feel that the weight's come back on again.

Dr Susan Carland: You have been in this industry for a long time, and you must have seen some changes in the way society thinks about weight loss. What have you seen in the way society has evolved or devolved in its approach to weight loss?

Michelle Bridges: Well, when people ask me about this conversation, and I kind of have to consider how long this conversation has been going for, one story that sticks in my mind is when I renovated a house. Many years ago, I was pulling up the floorboards, and underneath I found all these newspapers from the 1940s and 1950s. And on those newspapers were commercials for cigarettes, and all sorts of things, and diet pills.

And I thought, okay, this is a conversation that's been going on well before I arrived in this world, and probably many years before even then.

Voice Clip 1: What's the best way to reduce? Eat plenty, or starve yourself? Starve yourself? Wrong.

Voice Clip 2: It's like a fast. I'm a waistline watcher from way back.

Voice Clip 3: Well, that's enough for today.

Voice Clip 1: Lose excess weight naturally and fast, and save –

Michelle Bridges: So, it's something that has been in our society or in our culture for a long time. I definitely think we've seen almost what you would call a tsunami of obesity in the last 30 years, which has been amplified by our environment, and the way in which we have food that's very high in calories and very low in nutrition that's available for us at any point during the day.

And that was something that was certainly not available in the ’40s and ’50s, or even potentially in the ’60s that much. So, there's definitely been an amplification of the problem, or the issue, or however you want to put it, and certainly of the conversation that comes along with it as well.

Dr Ahmad Aly: It's not a coincidence that before COVID came along, the epidemic, and the even pandemic, actually, if you look at it, was obesity.

Dr Susan Carland: Dr Ahmad Aly is a general surgeon and specialist upper-gastrointestinal surgeon. He's the head of upper-GI surgery at the Austin Hospital here in Melbourne, and has performed thousands of weight loss surgeries. He also happens to be my brother-in-law.

Dr Ahmad Aly: Obesity in the West has become the single most prevalent, reversible cause of premature death. It's overtaken smoking. In Australia, the incidence of overweight and obesity is now approaching 70 per cent. Obesity itself is 30 per cent of our adult population. Our children are sitting at around 26 per cent overweight and obese, and increasing alarmingly.

And this trend is continuing. And not only that, the most rapid increase is actually at the very heaviest standard, at the morbid obesity end. And there's no sign of it slowing down. It's a disaster. It already, even just from an economic perspective, we're talking about billions of dollars every year. The direct cost of obesity in Australia is billions of dollars every year.

And yet, we continue to fluff around the edges and not think about this seriously. So, yeah, 20 years from now, there'll just be more of it, more burden on the health dollar, more burden on our health resources. This is a subject that's been talked about for a long time, but there's been very little inroads in terms of actual practical strategy.

Dr Susan Carland: There is still this attitude that if you are overweight, fat, whatever word you want to use, that it's a moral failing.

Dr Ahmad Aly: Yeah. Unfortunately, that's right. I think, like in many areas, the community, society at large, hasn't quite kept up with where the science is.

And particularly in this area, because it's so ingrained in us, isn't it, that we make assumptions about people that are suffering with their weight? We talk about people that are suffering obesity or overweight, and immediately there are certain assumptions that are conjured up in our mind. That they lack discipline, for example, or that they can't apply themselves. If only they just ate less, or if they exercised more, as if it was their choice to be large.

That's sort of what underpins it, I guess, is this idea that, well, it's just a matter of self discipline, and if you really wanted to, you could just apply yourself and you'd lose weight.

And yet, every observation we make shows that just simply isn't true. So, you're right. Weight is stigmatised. We do tend to make assumptions about people that are suffering overweight or obesity.

Dr Hilary Offman: It's absolutely one of the most legitimate forms of discrimination.

Dr Susan Carland: Dr Hilary Offman is a psychiatrist and psychoanalyst and lecturer at the University of Toronto. She often writes about fat phobia, and the role shame plays when it comes to being overweight.

Dr Hilary Offman: It's seen as a choice. You know, people can't change the colour of their skin, but they can change their size. And so, there's this sense that if you're fat, it's because you're lazy and you're unmotivated, and you're non-compliant with your doctor's advice, and that you choose to be fat, and that you don't care. You don't care about yourself, you don't care about your loved ones, you don't care about the rest of society.

And, of course, that is an assumption that comes from a belief that individuals are always responsible for their own outcomes. The term that I've heard applied to that is a “neoliberal healthism”.

Dr Susan Carland: What does that mean?

Dr Hilary Offman: Well, what that means is that the society is very invested in people believing how one is, and in this case fat, is up to the individual to determine.

And that means that if they're fat, it's their fault, because they could choose not to be fat. But what that does is, it takes society off having any responsibility for it.

Things like poverty, and education, and lack of privilege, and knowledge, and genetics, all of those things are diminished, such that the blame becomes that of the individual. And I think that perpetuates all the other things that go along with being fat that nobody really wants to own.

I mean, in our Instagram world, people want to look how they want people to see them, not necessarily how they are. And so, we see all these instances of Photoshopping that is absolutely absurd. Nobody wants to be real, because there's something wrong, somehow, with having vulnerabilities in general, especially ones that people can see.

And I think, from a societal point of view, there's a lot invested in a multi-billion-dollar industry that people pay for to be thinner. To buy the Peloton, not go for a walk. To buy the fancy makeup, to get the plastic surgery, the fancy cars, whatever it is.

There is a lot of reason why, in a capitalist society, people don't want to give it up, because there's a lot of money to be made at people's lack of confidence and belief that they're not good enough. So, those are a couple of reasons. And I think part, there's also the issue of there's just a lack of knowledge.

Dr Susan Carland: Here's Dr Michael Cowley again.

Dr Michael Cowley: I think humans have a capacity to single out people that are different on a variety of levels, and I think it's probably an evolutionary basis of tribalism there, from the beginning. I think there remains an underlying virtuosity in lean athleticism. And I think there's probably, again, a good evolutionary basis for that, and we idolise the Spartans for their vigour and leanness. And I think from that flows the capacity to stigmatise people who don't hold up such lofty physical ideals. Dr Susan Carland: What do you think the average Australian misunderstands about obesity?

Dr Michael Cowley: I think there's a fundamental misconception that it's just about willpower. And there's a fundamental misconception that obesity is caused by sloth and gluttony.

Dr Susan Carland: Yep.

Dr Michael Cowley: And all three are untrue.

Dr Susan Carland: So, if it's not just about willpower, how does science explain the link between weight and genetics? Here's Ahmad Aly again. There has been a real change in the way the scientific community has understood weight loss in the last couple of decades, particularly the link between weight and genetics. Can you tell us about that?

Dr Ahmad Aly: Yeah, Susan, that's right. I think particularly the last 10 years or so, there's been a lot of research in this area. And it was really stimulated by observations nearly 30, even 40 years ago, of identical twins.

Now, identical twin studies, where the twins are actually raised in separate households, for whatever reason – they've been separated at birth, and they're raised in separate households. And these twins have actually contributed a lot to medical science. They've been studied in many ways.

But one of the observations that was made was that within very close parameters, within a couple of kilograms, the identical twins tended to have identical weight, regardless of the family, social circumstances, et cetera, that they were raised in. And that's, if you like, was initial evidence to say, maybe there's a genetic component to weight here that we're not paying attention to.

Everyone understands weight is related to what you eat, and how you eat, and what energy you burn up, so what exercise you do. And yet, here were some observations that were saying, well, maybe it's not quite that simple.

And I think that's what the science of the last 10 years has demonstrated. There've really been extensive studies into, why is it particularly that people that have excess weight, that suffer with excess weight, why is it they find it so hard to lose that weight and to keep it off?

Dr Susan Carland: So far, we've heard that only one in five people who try to lose weight are successful at keeping it off, and that weight loss may simply be out of our control, and come down to our genetics or our environment. Which makes me wonder, is there any hope at all if we want to keep it off? Here's Dr Michael Cowley again.

I imagine for people listening to this, the 80 per cent who lose weight and put it back on, this would actually be quite a demoralising conversation. Because they would think, so, what? It's hopeless? I will never be able to keep the weight off that I want to lose?

Dr Michael Cowley: Yeah. I would hate to give that impression. Any weight loss is beneficial for your health, and it's possible to lose weight. It is harder than people think. And there's lots of approaches that work to help people lose weight, from diet plans, to formulised meals, to surgery and drugs where I work. All those things can help.

And I think we haven't explored the changes we can make to our environment to help facilitate better weight control. But obviously, if you need to drive everywhere, then your chance to incorporate daily activities that'll help you control weight is lower. And so, there's lots of changes we can make, and those will help that 80 per cent.

Dr Susan Carland: Is that people who have engaged only in their own diet and exercise programme, or does that include things like bariatric surgery, medication? I guess I'm wondering, are some things more effective than others?

Dr Michael Cowley: So, the one in five that I'm referring to are people who make lifestyle changes. So, that's changes in diet, and changes in the way they engage with their environment. Activity, really. The rest isn't included in that analysis.

And that data comes from something called the long-term weight control registry, run by an academic called Rena Wing in the US, and she tracks people who successfully lose weight and keep it off for a long time. And there are particular characteristics that are associated with long-term weight loss and long-term weight maintenance that we can explore if you want to.

Dr Susan Carland: I would love to explore. What are they?

Dr Michael Cowley: So, if it was any other condition, you'd probably call it obsessive-compulsive behaviour. They have quite detailed plans for their days, apparently, like detailed meal plans, and very bland meal plans. And I guess the rationale there is if it's lettuce for lunch and lettuce for dinner and lunch again tomorrow, you're not going to say, "Oh, ripper, I love lettuce. I'll have some more." You have no incentive to eat more because it's a novelty, and we know humans love novelty. We'll always eat more at the buffet than you will if you just make one plate.

So, the detailed meal planning, boring meals, calorie-controlled meals, and very high levels of activity. Because as they've lost weight, their bodies become more energy efficient, and so to replace that lost involuntary effect, they have to voluntarily exercise more. And so, it's an hour or more of aerobic exercise a day for most of those people.

Dr Susan Carland: Right. So, not only is it incredibly disciplined, but the mentality of someone who does that is quite specific. Most people couldn't be happy to live for the rest of their lives on very regimented, bland food.

Dr Michael Cowley: Absolutely. I agree. Yeah. And so, that's why it's better to educate the population about not getting to be overweight and obese, rather than trying to help them lose weight.

Dr Susan Carland: Is that something of a losing battle though? Like you said, if it's epigenetics, if it's the environment that we're in, we'll just switch on the genes for some people and make it harder for that person to resist the high-calorie environment they're in, as opposed to someone else. How much can education protect that person?

Dr Michael Cowley: It's the best we've got, I guess. Clearly, some people don't become overweight now. 30 per cent or 40 per cent don't. But it's much harder to roll things backwards. And the argument the public health people use is about putting an ambulance at the bottom of the cliff and trying to throw people back up. No, no. I mean, obviously that's not a solution to anything. So, we need to intervene to help people understand good choices. We need to intervene to help people interact with their environment in a more healthy manner to help them not become overweight, because it's very hard to unroll that once it happens. And the body makes changes that are apparently irreversible.

Dr Susan Carland: That's quite terrifying, I have to say, as I'm sitting here.

Dr Michael Cowley: It is. And the other, I guess, disturbing part of it is it becomes harder as we get older. So, as we age after 30 or 35, we start to lose muscle mass, and we replace that with fat. Muscle burns much more energy at rest than fat does, and so for every year after 35 or so, you need to either be more active, or eat less, to stay weight stable.

Now, you can counteract that by a training regime that helps you build muscles, and to maintain that muscle mass. And that's really healthy because exercise is terrific for you anyway. And those kind of training regimes that maintain muscle mass also maintain bone strength, so that's really good as well.

But we're not paying much attention to this yet, and I think this is the next horizon of healthy ageing, and we have to intervene. Not at 65 when people are getting aged, but at 35 when they can make changes that will set them up for a better ageing.

Dr Susan Carland: It seems like losing weight is harder than we think, particularly because of the high chance we'll put it back on. However, it is possible. When you join up on our next episode, I'll seek the best advice from our experts on some of the ways weight loss can be achieved. We'll also continue our discussion on the way we talk about weight.

Thank you to our guests today, Dr Michael Cowley, Dr Ahmad Aly, Dr Hilary Offman and Michelle Bridges. Visit our show notes to learn more about their work.

Thank you also to the Monash University Performing Art Centre's David Lee Sound Gallery, where a portion of this season was recorded.

If you're enjoying What Happens Next?, don't forget to give us a five-star rating on Apple podcast or Spotify, and share the show with your friends. Thanks for joining us. See you next week.