Dr Rupy: Can we be addicted to food? This is quite a hot topic and one that is more relevant than ever. On the one hand, we've got food companies and respected scientists telling us that food addiction is a myth. We don't see people smashing windows or stealing money from loved ones to fund a hamburger habit. I mean, this whole concept of food addiction must be farcical. However, on the other hand, recent work on food use disorders has demonstrated that the same neurobiological pathways implicated in drug abuse also modulate food consumption. And if you consider obesity that costs the UK 47 billion a year and has the second largest impact on the economy of around 3% of GDP, this is after smoking, we should really be properly discussing whether food addiction is real and plays a role in this. I mean, there's a lot to lose. So on the podcast today, we've got the amazing obesity researcher, Dr Nick Fuller, who you may remember from a previous episode on obesity, and he brings together a diverse set of skills, having held positions in both the industry and academic sectors. His current position as commercial and industry program leader within the Charles Perkins Centre at the University of Sydney involves working with government and industry to identify and develop cost-effective treatments for the treatment and management of obesity and related physical and mental health disorders. He's also the author of three bestselling books on the interval weight loss program. And Nick's work has resulted in policy change in the field of obesity and metabolic disease, and his research has been published in the esteemed journals, The Lancet and JAMA. Now, if you remember from that podcast episode that I hope you listen to before you listen to this because it will give a bit of context and framing for our discussion, we talk about how the environment conspires against you and your body, particularly when you go on a diet, is again fighting against you and what your aspirations might be to lose weight. Your body is like, no, that's not what's going to happen here because you put it in in sort of a starvation mode, and so it will adapt, not only fuel partitioning, but also behaviours as well. So today, what we're going to be talking about is this whole concept of food addiction, what food addiction actually means, what addiction itself entails, how the brain shapes your food choice, and the body's regulation of food intake, which involves a complex set of both peripheral and central networks. So peripheral being your gut and how that modulates different hormones that can have an impact on your brain and how that works as well. And how, as Dr Nick talks about, you can rewire your brain to change behaviours that are suited and in line with your health goals. Also, how long that will practically take as well. So for how long those behaviours will have to be forced until it actually becomes habitual. We also talk a bit about the environment, stress and psychological state in food choice that I'm personally interested in. And I think we're probably going to need another podcast episode to talk about just the impact of the environment. If you are interested in that, I would highly recommend listening to a podcast that I did with Jack Bobo a couple of episodes before about how the food environment dictates what food choices we make. It's called Why Smart People Make Bad Food Choices. Remember, you can find all of this information and more at thedoctorskitchen.com and sign up for the newsletter where I share practical tips on what to eat, listen to, read or watch once a week to help you lead a healthier lifestyle. Onto the podcast. Nick, thank you so much for coming back on the podcast. It's a pleasure to have you back. We've had some really good feedback on that pod, as I hear that you have as well.
Dr Nick Fuller: Yeah, it's it's been fabulous. The response that I had from our initial chat, it was a great honour to be on your show. I'm very grateful to be back and it's it's good to be talking to you again from Sydney, Australia. So greetings, Dr Rupy.
Dr Rupy: We were just saying, so I'm meant to be in Sydney in literally like three or four days now, plus obviously the travel. And we were thinking about whether we could do this podcast in person. I really miss like sitting down opposite a colleague or a friend in this case and just having that one on one because there's only so much you can do via Zoom, but we'll deal with it for now. But I thought rather than risk it, because with everything going on right now with the variant and stuff, I thought we'd just get it in the can and then we can just go for a coffee if I do make it to Australia.
Dr Nick Fuller: Yeah, absolutely. And some Tim Tams, remember. Which is very relevant to today's chat being food addiction. Absolutely, yeah, it's a very good point. So why don't we provide a little bit of context to the listeners if they haven't listened to the initial podcast that we've done. So if you are listening to this for the first time, I would recommend you go back and listen to that episode, but if you can't be bothered, Nick, why don't you give us a brief overview of what we talked about with regards to weight loss and some of your research as well? Yeah, absolutely. So we delved into why it's so hard to struggle or why it's so hard to succeed long term with our weight loss, you know, attempt. And it does come down to a couple of different reasons, but we jumped into the physiological responses to weight loss. Basically, the minute you sign up to a diet or attempt to lose weight, unfortunately, your body's going to work against you and not with you. It's going to go into shutdown mode, and there will be this biological imperative to regain weight. So things like your metabolism lowering, your appetite hormones changing, telling you to eat more, your thyroid function being suppressed, your adrenal glands pumping out more cortisol. All these things work against you. Eventually, the weight loss will plateau, but then worse still, it will start to climb back and you will regain that weight you lost. And this is the very reason why we are struggling to succeed long term on our weight loss journey. We all talk about the short-term wins. There's no doubt that diets do help us with short-term weight loss, but what we're not addressing is that weight regain that we're experiencing. And that does happen sometimes within a few months, but definitely happens within a few years. And worse still, you might actually do more damage than good in that you could drive up your set point because your body gets very good at shutting down, preparing for that next bout of starvation and putting on a little bit of extra fat. And that's again, just because it's in order to survive. It's leftover from our time as hunter gatherers and it's that evolutionary propensity to regain weight we've lost. So I do encourage you go back and have a listen to that. Ties in nicely to today's one because when you look at the obesity epidemic, I mean, there are two main contributors. Obviously, the environment's hard. Food addiction and overcoming that addiction to our favourite foods, the processed and fast foods on every corner of every block. That's something that's a big struggle. Also, the fact that we use motor vehicles to get everywhere now from A to B, so we're not moving as much and we get poor sleep. So lifestyle's one, but then what happens is the waistline goes up and we have this reactionary response. And that is by diet, through dieting, signing up to the latest fad or the new diet. But what happens is, as I just discussed and as we discussed in detail on that previous podcast, there is that biological imperative to regain the weight. You're up against your body and it's very hard to overcome that. But we did give some practical tips on long-term weight loss success, talked about some of my science. But today's one, if you think about this obesity epidemic, the problem didn't really come about until the sort of 1970s, 1980s. We did a very good job at regulating our body weight and keeping within a normal healthy weight range. But then we did start to see this boom of the processed and fast foods. And I guess the regulation of our body weight is due to a very clever part of the brain called the hypothalamus. Now this part of the brain actually receives signals both centrally and peripherally from various organs and tissues like your brain, but also other tissues in the body like your pancreas, your adipose tissue, and your stomach. They release hormones which act on your brain telling you when and when you shouldn't eat. So for example, when you haven't eaten for a while, ghrelin will be released from your stomach, tells your brain to go and get some food. As you start to eat, other hormones are then released like PYY, GLP-1, telling you to terminate food consumption, to put down that food. So that clever wiring system between say, for example, our stomach and our brain worked perfectly well. Most of us stayed within a healthy weight range, but then we see this explosion of the modern day environment and the fast food on every corner. The problem is the hypothalamus also receives inputs from reward circuits. Now this is known as our hedonic pathway. It can actually override the homeostatic regulation of our body weight or the homeostatic system, and it's why we continue to eat even when our energy stores are full. And the very best example is the evening meal and dessert. So we've just finished our evening meal and out comes the dessert. And guess what? We can always manage to say yes, we can always fit it in even though our energy stores are full. So this is the hedonic pathway creeping in. It's making it very hard in the modern day environment to manage our weight because we keep saying yes to all of these favourite foods, which are often low in nutrition, high in calories. So this is what we're going to jump into in today's chat. And it's one of the big contributors to the obesity epidemic. We need to be able to overcome this addiction to food and retrain our brain back to nature's treats.
Dr Rupy: Yeah, absolutely. I mean, let's start off a couple of steps back actually, because I think the concept of food addiction for a lot of people hasn't really entered their understanding. They haven't really come across this before. And I think intuitively, people know that they have things like cravings, they have desires for certain foods. It might even be at certain times of the month or in reaction to certain elements as well. And also, aside from that, the concept of food addiction is almost quite controversial within the nutritional world. Some people believe in it, some people don't. I mean, I know which camp I'm in. But maybe we should talk about exactly what addiction means. So in the traditional sense, there are characterizations that we have using things like DSM criteria, ICD criteria, depending on which geographical location you are. And from my understanding, looking at substance abuse is a good sort of comparative marker to tell whether we actually are dealing with a true addiction. And so when I think about addiction, it's that compulsion to seek and consume said substance, whatever that substance might be. And in that compulsion, you lose that control, that sort of feedback mechanism, which would lead to overconsumption. And then in addition to that, you have physical and emotional symptoms when you remove said substance as well. I mean, those are just three elements of addiction. Those are the things that come to mind. I mean, there's a whole long list of criteria that meets addiction. Looking at that criteria, can we, do you think we can compare those maladaptive patterns of behaviour with specific elements of food, whether that be sugar, whether it be certain types of foods that you find in convenience environments and what's littered in our food environment? How do we frame that food addiction using that kind of context?
Dr Nick Fuller: Yeah, personally, absolutely. It's pleasure-based habits that are the hardest to break, because these are enjoyable behaviours. They prompt your brain to release dopamine. Now, whenever we're prompting our brain to release dopamine, this is where we get into this addictive conversation. And in this instance, addiction to certain foods. They release feel-good chemicals in the brain. Dopamine is that learning chemical, which basically means that next time we see that food, our brain goes, hey, that was delicious last time, go back for more. So in the context of food, yes, because it's a pleasure-based release that we're getting, we're getting dopamine release, and this is why it is so hard to overcome that that sort of addiction to all these processed and fast foods on every corner of every block. So it can be put in the same category as as, you know, as drugs and and alcohol and other forms of addiction.
Dr Rupy: Yeah, yeah. And one of the other elements which is particularly important, I guess, as this podcast is coming out in January, which is around the same time that you're going to see a flurry of diets and people trying to, you know, make up for the overconsumption over Christmas. One thing that really comes to mind is this the concept of relapse. So in a lot of substances of misuse, whether it be alcohol, whether it be cocaine, whether it be other hard illegal substances, you find some element of people trying to break the habit, and they might be able to fight against those neurobiological pathways that they've built up and strengthened over time. And that period where they experience withdrawal can be extended, you know, seven days, 14 days, but then they have relapse. And so relapse is a really, really important concept to get your head around, particularly around this time of year, because people sort of feel that if they can't stick with a diet, it's down to poor willpower, whereas actually what we're going to be talking about today is how we've hardwired our system and we also are fighting against evolutionary systems that push us in the direction of consuming certain types of foods. And some people are even more hardwired than others. We'll get into genetics a little bit later. Is that is that fair to say? Would you agree with that?
Dr Nick Fuller: Yeah, absolutely. Just as we have this evolutionary propensity to regain weight, it's the same with food. We sought out foods, you know, that were high in energy, best bang for buck. And that was in order again, in order to survive. So they were foods high in sugar and high in fat, but they were naturally occurring in the environment. Now, nowadays, it's the high in fat, high in sugar foods, but they're the added fats, the added sugars from the processed and fast foods. And you have them all the time, and eventually something's going to give. That is the waistline. But like you say, it's got nothing to do with that lack of willpower. We are up against our biology. And the way to to actually regain control of your health and weight is to work with your body, not against it. And just as the problem is evolutionary, so too is the solution.
Dr Rupy: Yeah, yeah. Let's dive into some of the stuff that you were talking about earlier actually, in terms of that neurobiology. So the the reward centers and maybe we can also partition that out into the endocrinology that's going on. So the hormone base of how we stimulate those reward centers that can lead to overconsumption and food addiction. So what's going on in our brain? When I when I eat a lovely croissant with chocolate through it and cardamom and cinnamon, you can tell I'm pretty hungry. I haven't had breakfast yet. What is what is going on? And how can we compare that sort of one incidence of me consuming that croissant with perhaps, you know, a consistent eating of that nature that can drive an addictive behaviour?
Dr Nick Fuller: Yeah, okay. So I might try and address this in two different sections. I guess firstly, it's it's delving a little bit more into our ancestral history. So remember, during our time as hunter gatherers, as you just alluded to, food was hard to come by. Calories were scarce. This is what people really need to understand because this is all about why it's so hard to succeed long term. We are up against our biology. So we therefore learned to seek out foods that gave us best bang for buck. They were the foods high in energy, the ones that were palatable. And this was as mentioned, in order to or needed in order to survive. Now, during our ancestors' time, these were foods that were found naturally in the environment. They were foods high in sugar, such as the fruits and the honey, but they're also foods that are high in fat, such as the meat and the nuts. So these foods also gave us pleasure. This is the important thing to note. They would release those feel-good chemicals in the brain when we ate them, and they subsequently shaped our modern-day food choices. But you fast forward a few thousand years and to the modern-day environment, I mean, now the story is very different. Of course, you know, we're still seeking out these pleasure-seeking foods, but now we get those highs from fast food, the confectioneries, the pizzas, the soft drinks. And it's a far cry from those nature's treats we once sought. So we haven't evolved from these ancient survival circuits in the brain. And it's what we refer to as this evolutionary mismatch, meaning that the evolved traits that were once advantageous become harmful when placed in the modern-day environment. So, you know, with food, we have these calorie-seeking brains. They were this useful trait, but when that was when food was hard to come by, but now food is everywhere. We're submerged in this modern-day environment saturated with fast food, and we just can't control ourselves. Now, with respect to the physiology of the brain, I mean, the brain is an incredibly complex organ, and it is responsible for shaping our food choices. And a particular part of the brain called the prefrontal cortex. So the best way to visualize all of this in terms of what's going on is to think of it as a wiring system. So this wiring system within the brain. Now, the human brain actually contains neurons, and it contains approximately 100 billion of them. So loads of them. And each neuron in the brain actually has a long cable several times thinner than a human hair called an axon. Now, this is where you actually get signals sent from one neuron travelling along to be received by other neurons. Now, these neurons also have synaptic connections. They have up to 100,000 of these connections, which are formed from other neurons. So you've got this sort of complex connectivity in the brain. Now, these connections allow one neuron to communicate to another. And this is effectively referred to as the wiring of the brain. Now, this is important to know because the good news is that this hardwiring of the brain is in fact softwiring, and it can be retrained. And this is how you can overcome that addiction to all of those fast and processed foods. Now, we refer to this as neuroplasticity of the brain. And what I'm saying by that is you can change the wiring of the brain. It does respond to new environments, new situations, and new lifestyles. So I guess that's sort of putting into context, you know, we've got these ancient survival circuits. Let's work with them. We've sort of wired ourselves or hardwired ourselves to to processed and fast foods, but that hardwiring is in fact softwiring. We can retrain our brain back to nature's treats, which is what our ancestors used to seek out. So it's positive. You can do it. And you have to think of this complex wiring system as something that you can change over time.
Dr Rupy: Yeah, absolutely. It's interesting you say that about music and things like sex and all the sort of other pleasures. And that is a really good way, I think, to conceptualize this, at least in my brain anyway. So on one side of the spectrum, you have these highly, highly addictive substances that not only release the dopamine and they impact all those other reward centers, but they they try and reinforce that behaviour as much as possible because there is such a significant impact. On the other end of the spectrum, you have things like maybe music or going to the gym, very good behaviours, and they will light up those pleasure centers, but they have less impact that would lead to a spiralling negative impact on behaviour needing to overconsumption within reason. And then I think somewhere along that spectrum, probably more towards substances of misuse, looking at data over the last 10 years, you have food in that category and particularly food that is overly processed and high in sugar that we know that impacts those reward centers. And so that that sort of positive reinforcement via dopamine appears to be just one of those driving forces. But I want to bring it slightly towards the sort of the endocrinological aspect of this because we've been talking a lot about the brain, but as you know from your research, a lot of this rewarding behaviour also is impacted by what goes on in your intestines and your stomach and those hormones that are released. So you've got ghrelin and leptin, those are the two classic hormones, but also PYY and insulin to an extent as well. How do those impact the brain? How what what happens there when I eat something in response to ghrelin being produced? Maybe we could talk a bit about what ghrelin and leptin are as a refresher for people and then how that might impact overconsumption as well, particularly when it comes to processed food and sugars.
Dr Nick Fuller: Yeah, this is a good point. Ghrelin's a good one. A lot of us are familiar with ghrelin. I mean, when you get those hunger pangs, ghrelin levels are going to be increased. They're going to be released from your stomach. They're acting on your brain, that clever part of the brain, remember called the hypothalamus, telling you to eat more. So you go and reach for food. Now, unfortunately, we tend to be reaching for more of those processed and packaged foods. But as we tend to eat, as we start to eat the food, remember, we do have a cascade of other hormones being released from various organs and tissues, like the PYY, the GLP-1, the leptin, telling you to terminate food consumption. So this clever wiring system that does exist to hopefully keep us within a healthy weight range, but that hedonic pathway keeps creeping in, it keeps overriding the homeostatic regulation of our body weight, and we continue to eat even though our energy stores are full. So it's like what we're doing is suppressing and nullifying this clever wiring system. It doesn't, it's not working properly because these foods that are sort of cleverly engineered and manufactured in the modern-day environment, they just they keep yelling out to us and dopamine is released and we keep going back for more and more and more and we have a very hard time saying no. So you're sort of suppressing that very clever wiring system that does exist between the organs and tissues and your brain telling you when and when you shouldn't eat. So that's a big part of the problem. And also, you know, some of these hormones stop working as efficiently. We know when you when you increase your adipose tissue, leptin stops working as efficiently, even though it's produced in fat tissue, adipose tissue, it's not working as efficiently as it was when you're in a normal or healthy weight range. So there's a couple of different things going on there. And then the other thing is, which we've talked about previously too, is when you start to lose weight, this wiring system goes completely bananas. I mean, ghrelin levels go through the roof. Ghrelin levels go up telling you to eat more so that you regain that weight, and they tell you to keep, they stay elevated even after you've regained the weight so that you put on a little bit of extra weight. So you've got to sort of, yeah, a myriad of different things going on. It's it's definitely making it very hard to to say no because it's you're suppressing it, and then you react, you sign up to a diet, and then it stops working efficiently or works in the other way in that it tells you to continue to eat even though you're trying to lose weight.
Dr Rupy: Yeah, and I just want to anchor the listener as well. Like it sounds really doom and gloom with what we're talking about here. Like we're all destined to to continue overeat and and uh and uh, you know, we lose control of our impulses. But we are going to get to some practical solutions a little bit later on in the show, just to remind people. So to just to sort of clarify, so we have ghrelin that's released from the stomach and that has a positive impact on food seeking behaviour. A lot of people don't realize that even though that is being released from the stomach and it leads to a whole cascade of hormones, it's having that direct impact on dopamine and dopamine bodies in parts of the brain as well. And the same thing can be said of leptin. Leptin being released from fat cells and you've got PYY being released from the intestines. These cascade again to inhibit dopamine. So they inhibit dopamine and thus reduce food seeking behaviour. And what can go out of whack is when you are on that diet, when you are overweight and you have like an imbalance of that system. So you can see already, you know, we have addictive properties of the food itself. You have the impact of excess weight gain. You have the impact of dieting as well. So if you're doing a crash diet, your your body is going to be fighting against you, very similar to what we discussed last time on the pod as well. And so you can already see this pattern of why you lose, quote unquote, willpower. So if anyone's listening to this and it's, you know, January, you've been on a diet, hopefully this is giving you a bit more context as to why it's not, it's not your fault. It's the fault of your body and the fault of your food environment. And I think the food environment has a lot to play in this as well.
Dr Nick Fuller: Yeah, definitely. And even with the ghrelin, as you just alluded to, as we make those unhealthy food choices, you know, we're suppressing this clever wiring system, but we're also changing the prefrontal cortex, that part of the brain that's responsible for our lifestyle choices. So it's made up of the grey and the white matter, but you're actually reducing the grey matter in that part of the brain as you continue to reach for the croissant, the can of Coke, the pizza, whatever it might be. But if you can retrain your brain to reach for more of the healthier food choices, you can increase that grey matter and it does make it easier over time. So it's definitely not all doom and gloom and remember, it does come back to this neuroplasticity of the brain. That softwiring exists, you can retrain it, and you can regain control of your food choices, your lifestyle choices, your health and your weight.
Dr Rupy: Yeah, yeah. You can tell I'm really interested in this because I looked at a couple of studies where they examined dopamine receptors in addicted patients as well as in obese patients as well. And they found that the receptors for dopamine are found to be lower in addiction imaging studies. So what that means, just for the listener, is that if you have less receptors, you need more dopamine hits to have the same desired effect. And what they found in obese subjects is the same pattern. So you actually have a downgrading of dopamine receptors such that you need to have more of whatever substance it is that you are consuming for the dopamine hit to have the same effect, which again can just give a little bit more understanding as to why we have these overconsuming behaviours. Is this something you've come across in in perhaps your clinic or in practical examples?
Dr Nick Fuller: Yeah, definitely. So remember what you're doing is you're actually suppressing this clever wiring system. You're stopping it from working efficiently. You have that hard time saying no to your favourite foods, and over time, it stops working as efficiently. And as you just mentioned, it's harder to get that high. What's also fascinating is these research studies where we sit down participants to different types of food and we use an imaging technique called fMRI, functional magnetic resonance imaging. We can measure the blood flow within the brain. Now, when we put these participants down in front of the processed and packaged foods, you know, we see the heightened activity of the dopamine in the brain and all those feel-good chemicals, specifically in the prefrontal cortex. But interestingly, when we sit them down in front of the nature's treats and their favourite nature's treats, we also get that same response and heightened response in the brain. So we're also seeing the dopamine release, which is what we're after. And remember, it's all about retraining our brain back to those foods that we used to seek and get pleasure from.
Dr Rupy: No way. So you're saying that we can, we can have that positive reinforcement, that dopamine release in response to natural products. And I'm assuming it's things like, I don't know, apples or barley or greens, that kind of stuff. Is that, am I getting that wrong?
Dr Nick Fuller: Absolutely, definitely. So remember, we want to rewire the brain back to healthy foods. We always sought these foods out. They gave us the pleasure and they were the ones our ancestors sought out. Now, foods that are naturally high in sugar and or fat give us the same high as the processed and packaged foods. This is what people really need to understand and appreciate because once you get that understanding, it's so much easier to retrain your brain back to those foods because think about it, the ones that are naturally high in sugar, the fruit, your favourite fruits, you know, the ones that are high in fats, natural added fats, not the added fats, the natural fats like your avocado, nuts and seeds, they make us feel good. But we just don't go to them as the default because we keep going back to the vending machine or the drive-through or the convenience store. If you surround yourself with those foods and you remember how good they're going to make you feel, it goes a long way to retraining your brain. So yes, you're exactly right. Those foods that are naturally high in sugar, the papaya, the berries, the nuts and the seeds and the avocados, well, they are high in sugar, they're high in fat, and they give us that same high, the same dopamine hit in the brain that we get from processed and packaged foods.
Dr Rupy: Oh, that's epic. I mean, you can tell like it's summer where you are because you're talking about the exotic fruits and stuff that we have. And it's like in the middle of winter here, which I haven't seen a papaya for months. So, but just taking it a step back because I do want to talk about the practical applications of this knowledge and how you can form new habits and why habit forming is hard in itself. But let's just talk a little bit about the environment at large because from my understanding, the reason why people fall into substance misuse, if we bring it back down to to cocaine and other illicit substances, it's not just a product of the of the substance itself and its addictive properties, but it's also the environment in which we take said substances. So the impact of stress, the impact of depression, the impact of environment, the lack of social cohesion. These are all things that compound that problem of substance misuse. We see it in America with the the current epidemic with with opioids. We see it with people in the UK as well who are more likely to be in vulnerable circumstances that fall into that pattern of substance misuse. And you can draw a parallel with processed foods, unhealthy foods in the same type of context as well. Is this something that you feel and you see compounds that problem and what do you think the impact of stress is at a neurobiological level?
Dr Nick Fuller: Um, yeah, look, I guess it also ties into the difficulty sticking to goals. I mean, it's highly influenced by others, isn't it? Um, you know, as a tribal society, people are made uncomfortable by those breaking the mold. Um, and even though your decision to decline, for example, that that wine and cheese at the afternoon gathering, it's going to be difficult. It's the decision you need to make and you need to be able to learn to say no so that you can see that retraining of the brain back towards nature's treats and and see the healthier food choices become easier with time. So, I think that's a big part of it. I mean, people that our our company forms a big part, our environment forms a big part, as you mentioned, into the food choices and the lifestyle choices we make. So it does come down to some of that identity accountability, being accountable for your actions, and putting yourself in new environments to make it easier to make those healthier food choices and lifestyle choices.
Dr Rupy: Yeah, absolutely. I see certainly from a clinical perspective, the impact of stress and overeating and the other sort of collection of psychological insults that can lead to someone having a negative relationship with food. And if you look at that in the context of the food environment that a lot of people in financially underprivileged areas will find themselves in, those convenience, hyper-palatable foods are abundant. And it's, you know, it's it's so hard to break out of that pattern, right? So that's definitely got to be contributing to the addictive properties of food itself.
Dr Nick Fuller: Yeah, remember your brain likes habits. They're efficient. And when you automate common, you know, actions, you free up mental resources for other tasks. And when that's what people need to understand because this is all about why it's so hard to succeed long term. We are up against our biology. So we therefore learned to seek out foods that gave us best bang for buck. They were the foods high in energy, the ones that were palatable. And this was as mentioned, in order to or needed in order to survive. Now, during our ancestors' time, these were foods that were found naturally in the environment. They were foods high in sugar, such as the fruits and the honey, but they're also foods that are high in fat, such as the meat and the nuts. So these foods also gave us pleasure. This is the important thing to note. They would release those feel-good chemicals in the brain when we ate them, and they subsequently shaped our modern-day food choices. But you fast forward a few thousand years and to the modern-day environment, I mean, now the story is very different. Of course, you know, we're still seeking out these pleasure-seeking foods, but now we get those highs from fast food, the confectioneries, the pizzas, the soft drinks. And it's a far cry from those nature's treats we once sought. So we haven't evolved from these ancient survival circuits in the brain. And it's what we refer to as this evolutionary mismatch, meaning that the evolved traits that were once advantageous become harmful when placed in the modern-day environment. So, you know, with food, we have these calorie-seeking brains. They were this useful trait, but when that was when food was hard to come by, but now food is everywhere. We're submerged in this modern-day environment saturated with fast food, and we just can't control ourselves. Now, with respect to the physiology of the brain, I mean, the brain is an incredibly complex organ, and it is responsible for shaping our food choices. And a particular part of the brain called the prefrontal cortex. So the best way to visualize all of this in terms of what's going on is to think of it as a wiring system. So this wiring system within the brain. Now, the human brain actually contains neurons, and it contains approximately 100 billion of them. So loads of them. And each neuron in the brain actually has a long cable several times thinner than a human hair called an axon. Now, this is where you actually get signals sent from one neuron travelling along to be received by other neurons. Now, these neurons also have synaptic connections. They have up to 100,000 of these connections, which are formed from other neurons. So you've got this sort of complex connectivity in the brain. Now, these connections allow one neuron to communicate to another. And this is effectively referred to as the wiring of the brain. Now, this is important to know because the good news is that this hardwiring of the brain is in fact softwiring, and it can be retrained. And this is how you can overcome that addiction to all of those fast and processed foods. Now, we refer to this as neuroplasticity of the brain. And what I'm saying by that is you can change the wiring of the brain. It does respond to new environments, new situations, and new lifestyles. So I guess that's sort of putting into context, you know, we've got these ancient survival circuits. Let's work with them. We've sort of wired ourselves or hardwired ourselves to to processed and fast foods, but that hardwiring is in fact softwiring. We can retrain our brain back to nature's treats, which is what our ancestors used to seek out. So it's positive. You can do it. And you have to think of this complex wiring system as something that you can change over time.
Dr Rupy: Yeah, absolutely. It's interesting you say that about music and things like sex and all the sort of other pleasures. And that is a really good way, I think, to conceptualize this, at least in my brain anyway. So on one side of the spectrum, you have these highly, highly addictive substances that not only release the dopamine and they impact all those other reward centers, but they they try and reinforce that behaviour as much as possible because there is such a significant impact. On the other end of the spectrum, you have things like maybe music or going to the gym, very good behaviours, and they will light up those pleasure centers, but they have less impact that would lead to a spiralling negative impact on behaviour needing to overconsumption within reason. And then I think somewhere along that spectrum, probably more towards substances of misuse, looking at data over the last 10 years, you have food in that category and particularly food that is overly processed and high in sugar that we know that impacts those reward centers. And so that that sort of positive reinforcement via dopamine appears to be just one of those driving forces. But I want to bring it slightly towards the sort of the endocrinological aspect of this because we've been talking a lot about the brain, but as you know from your research, a lot of this rewarding behaviour also is impacted by what goes on in your intestines and your stomach and those hormones that are released. So you've got ghrelin and leptin, those are the two classic hormones, but also PYY and insulin to an extent as well. How do those impact the brain? How what what happens there when I eat something in response to ghrelin being produced? Maybe we could talk a bit about what ghrelin and leptin are as a refresher for people and then how that might impact overconsumption as well, particularly when it comes to processed food and sugars.
Dr Nick Fuller: Yeah, this is a good point. Ghrelin's a good one. A lot of us are familiar with ghrelin. I mean, when you get those hunger pangs, ghrelin levels are going to be increased. They're going to be released from your stomach. They're acting on your brain, that clever part of the brain, remember called the hypothalamus, telling you to eat more. So you go and reach for food. Now, unfortunately, we tend to be reaching for more of those processed and packaged foods. But as we tend to eat, as we start to eat the food, remember, we do have a cascade of other hormones being released from various organs and tissues, like the PYY, the GLP-1, the leptin, telling you to terminate food consumption. So this clever wiring system that does exist to hopefully keep us within a healthy weight range, but that hedonic pathway keeps creeping in, it keeps overriding the homeostatic regulation of our body weight, and we continue to eat even though our energy stores are full. So it's like what we're doing is suppressing and nullifying this clever wiring system. It doesn't, it's not working properly because these foods that are sort of cleverly engineered and manufactured in the modern-day environment, they just they keep yelling out to us and dopamine is released and we keep going back for more and more and more and we have a very hard time saying no. So you're sort of suppressing that very clever wiring system that does exist between the organs and tissues and your brain telling you when and when you shouldn't eat. So that's a big part of the problem. And also, you know, some of these hormones stop working as efficiently. We know when you when you increase your adipose tissue, leptin stops working as efficiently, even though it's produced in fat tissue, adipose tissue, it's not working as efficiently as it was when you're in a normal or healthy weight range. So there's a couple of different things going on there. And then the other thing is, which we've talked about previously too, is when you start to lose weight, this wiring system goes completely bananas. I mean, ghrelin levels go through the roof. Ghrelin levels go up telling you to eat more so that you regain that weight, and they tell you to keep, they stay elevated even after you've regained the weight so that you put on a little bit of extra weight. So you've got to sort of, yeah, a myriad of different things going on. It's it's definitely making it very hard to to say no because it's you're suppressing it, and then you react, you sign up to a diet, and then it stops working efficiently or works in the other way in that it tells you to continue to eat even though you're trying to lose weight.
Dr Rupy: Yeah, and I just want to anchor the listener as well. Like it sounds really doom and gloom with what we're talking about here. Like we're all destined to to continue overeat and and uh and uh, you know, we lose control of our impulses. But we are going to get to some practical solutions a little bit later on in the show, just to remind people. So to just to sort of clarify, so we have ghrelin that's released from the stomach and that has a positive impact on food seeking behaviour. A lot of people don't realize that even though that is being released from the stomach and it leads to a whole cascade of hormones, it's having that direct impact on dopamine and dopamine bodies in parts of the brain as well. And the same thing can be said of leptin. Leptin being released from fat cells and you've got PYY being released from the intestines. These cascade again to inhibit dopamine. So they inhibit dopamine and thus reduce food seeking behaviour. And what can go out of whack is when you are on that diet, when you are overweight and you have like an imbalance of that system. So you can see already, you know, we have addictive properties of the food itself. You have the impact of excess weight gain. You have the impact of dieting as well. So if you're doing a crash diet, your your body is going to be fighting against you, very similar to what we discussed last time on the pod as well. And so you can already see this pattern of why you lose, quote unquote, willpower. So if anyone's listening to this and it's, you know, January, you've been on a diet, hopefully this is giving you a bit more context as to why it's not, it's not your fault. It's the fault of your body and the fault of your food environment. And I think the food environment has a lot to play in this as well.
Dr Nick Fuller: Yeah, definitely. And even with the ghrelin, as you just alluded to, as we make those unhealthy food choices, you know, we're suppressing this clever wiring system, but we're also changing the prefrontal cortex, that part of the brain that's responsible for our lifestyle choices. So it's made up of the grey and the white matter, but you're actually reducing the grey matter in that part of the brain as you continue to reach for the croissant, the can of Coke, the pizza, whatever it might be. But if you can retrain your brain to reach for more of the healthier food choices, you can increase that grey matter and it does make it easier over time. So it's definitely not all doom and gloom and remember, it does come back to this neuroplasticity of the brain. That softwiring exists, you can retrain it, and you can regain control of your food choices, your lifestyle choices, your health and your weight.
Dr Rupy: Yeah, yeah. You can tell I'm really interested in this because I looked at a couple of studies where they examined dopamine receptors in addicted patients as well as in obese patients as well. And they found that the receptors for dopamine are found to be lower in addiction imaging studies. So what that means, just for the listener, is that if you have less receptors, you need more dopamine hits to have the same desired effect. And what they found in obese subjects is the same pattern. So you actually have a downgrading of dopamine receptors such that you need to have more of whatever substance it is that you are consuming for the dopamine hit to have the same effect, which again can just give a little bit more understanding as to why we have these overconsuming behaviours. Is this something you've come across in in perhaps your clinic or in practical examples?
Dr Nick Fuller: Yeah, definitely. So remember what you're doing is you're actually suppressing this clever wiring system. You're stopping it from working efficiently. You have that hard time saying no to your favourite foods, and over time, it stops working as efficiently. And as you just mentioned, it's harder to get that high. What's also fascinating is these research studies where we sit down participants to different types of food and we use an imaging technique called fMRI, functional magnetic resonance imaging. We can measure the blood flow within the brain. Now, when we put these participants down in front of the processed and packaged foods, you know, we see the heightened activity of the dopamine in the brain and all those feel-good chemicals, specifically in the prefrontal cortex. But interestingly, when we sit them down in front of the nature's treats and their favourite nature's treats, we also get that same response and heightened response in the brain. So we're also seeing the dopamine release, which is what we're after. And remember, it's all about retraining our brain back to those foods that we used to seek and get pleasure from.
Dr Rupy: No way. So you're saying that we can, we can have that positive reinforcement, that dopamine release in response to natural products. And I'm assuming it's things like, I don't know, apples or barley or greens, that kind of stuff. Is that, am I getting that wrong?
Dr Nick Fuller: Absolutely, definitely. So remember, we want to rewire the brain back to healthy foods. We always sought these foods out. They gave us the pleasure and they were the ones our ancestors sought out. Now, foods that are naturally high in sugar and or fat give us the same high as the processed and packaged foods. This is what people really need to understand and appreciate because once you get that understanding, it's so much easier to retrain your brain back to those foods because think about it, the ones that are naturally high in sugar, the fruit, your favourite fruits, you know, the ones that are high in fats, natural added fats, not the added fats, the natural fats like your avocado, nuts and seeds, they make us feel good. But we just don't go to them as the default because we keep going back to the vending machine or the drive-through or the convenience store. If you surround yourself with those foods and you remember how good they're going to make you feel, it goes a long way to retraining your brain. So yes, you're exactly right. Those foods that are naturally high in sugar, the papaya, the berries, the nuts and the seeds and the avocados, well, they are high in sugar, they're high in fat, and they give us that same high, the same dopamine hit in the brain that we get from processed and packaged foods.
Dr Rupy: Oh, that's epic. I mean, you can tell like it's summer where you are because you're talking about the exotic fruits and stuff that we have. And it's like in the middle of winter here, which I haven't seen a papaya for months. So, but just taking it a step back because I do want to talk about the practical applications of this knowledge and how you can form new habits and why habit forming is hard in itself. But let's just talk a little bit about the environment at large because from my understanding, the reason why people fall into substance misuse, if we bring it back down to to cocaine and other illicit substances, it's not just a product of the of the substance itself and its addictive properties, but it's also the environment in which we take said substances. So the impact of stress, the impact of depression, the impact of environment, the lack of social cohesion. These are all things that compound that problem of substance misuse. We see it in America with the the current epidemic with with opioids. We see it with people in the UK as well who are more likely to be in vulnerable circumstances that fall into that pattern of substance misuse. And you can draw a parallel with processed foods, unhealthy foods in the same type of context as well. Is this something that you feel and you see compounds that problem and what do you think the impact of stress is at a neurobiological level?
Dr Nick Fuller: Um, yeah, look, I guess it also ties into the difficulty sticking to goals. I mean, it's highly influenced by others, isn't it? Um, you know, as a tribal society, people are made uncomfortable by those breaking the mold. Um, and even though your decision to decline, for example, that that wine and cheese at the afternoon gathering, it's going to be difficult. It's the decision you need to make and you need to be able to learn to say no so that you can see that retraining of the brain back towards nature's treats and and see the healthier food choices become easier with time. So, I think that's a big part of it. I mean, people that our our company forms a big part, our environment forms a big part, as you mentioned, into the food choices and the lifestyle choices we make. So it does come down to some of that identity accountability, being accountable for your actions, and putting yourself in new environments to make it easier to make those healthier food choices and lifestyle choices.
Dr Rupy: Yeah, absolutely. I see certainly from a clinical perspective, the impact of stress and overeating and the other sort of collection of psychological insults that can lead to someone having a negative relationship with food. And if you look at that in the context of the food environment that a lot of people in financially underprivileged areas will find themselves in, those convenience, hyper-palatable foods are abundant. And it's, you know, it's it's so hard to break out of that pattern, right? So that's definitely got to be contributing to the addictive properties of food itself.
Dr Nick Fuller: Yeah, remember your brain likes habits. They're efficient. And when you automate common, you know, actions, you free up mental resources for other tasks. And and like you said, if sometimes we're just in the habit of going to that fast food outlet. It's it's a cheap, it's a quick option and it's going to satisfy that need that we're looking for and that's that dopamine hit. So it's about breaking your usual routine and replacing an old habit with a new habit. And remember these pleasure-based habits are the hardest to break because enjoyable behaviours prompt your brain to release dopamine. So, look, you do need to be able to take accountability for your actions. You need to put yourself in new environments, you need to break old habits to do that. You need to form new or replace an old habit with a new habit. So instead of driving that same way home via the fast food, you know, you do go a different way. Instead of breaking up your afternoon work day with a walk to the vending machine, you know, you encourage yourself to do something different, whether it's an exercise workout or or just walking on a different route. But yes, it's about breaking down those those daily routines because we are creatures of habit. It's easy, frees up that mental space to allow us to focus on other things. Um, but we can still seek out that dopamine hit. Remember, it's easy to get that high. We want to get that high. We're not saying, you know, that's something we're going to we're going to neglect. We're going to satisfy that need, but we're going to do it with nature's treats. So you've got to surround yourself with those healthier foods. And over time, it does become an easier and easier decision to make.
Dr Rupy: Yeah, absolutely. And not to derail us totally here, but I'm really interested if there are any gender differences in food behaviour. I mean, certainly a lot of my colleagues have talked to me about carb craving, about the impact of menstrual cycles, the the detrimental impact of fasting actually. I've found a lot of of my colleagues have said that they've tried fasting, whether it be 5:2 or less than 500 a day for an extended period and had negative impacts. I mean, is that something that you've looked into yourself, those gender differences?
Dr Nick Fuller: Yeah, well, I guess when we're looking at the science, I mean, look, food that gives us pleasure is tasty, it's hard, therefore hard to resist. It's just like the high we get from having sex or listening to good music, we get that high from food. You know, we've talked about we need to seek that food out. We're going to do it, and we evolved to do so. And specifically food that's high in fat and sugar. Now, when we register a pleasure, endorphins are released simultaneously with dopamine into the brain's pleasure center called the nucleus accumbens. I think I pronounced that right. Look, the brain then remembers this sense of satisfaction next time you see it and it triggers a response. It's almost as if your brain's been hijacked. But that pleasure that was once derived from the fruits and the veggies, the honey, the nuts and the seeds, the nature's treats, well, it's it's it's no longer the case. We're getting that pleasure from the added sugar and and yes, it is just as as, I guess, as potent and as addictive as many of these other addictions that we have. We're getting that same release in the brain. This is why, remember, these habits are so so hard to to break and overcome because we're releasing and we're dealing with dopamine. This is that learning chemical that triggers a response every time you see that food. Instead of being wired to those foods that used to occur or do occur naturally, we're just being relied or we're relying on the heavily processed ones. As mentioned, they're low in nutrition, high in calories. They cause cravings when we see them. And as a result, they result in overconsumption due to a loss of control when we eat them. And that's when you can go and sit down, have the dessert even though you've had the dinner, or you walk past the bakery store, you can smell, see and taste that food from last time, and you want to go and buy something. So that added fat, sugar, and salt in those foods, they do trigger addictive-like eating behaviours. And that's what we see in that modern-day obsession with so many foods, cakes, the bakery treats, the pastries, the chocolates, the pizza, the hamburgers. We all have our favourites. So, so yes, it's it's it's releasing dopamine and this is why it is such a huge problem in the modern-day environment and why it's contributing to the obesity epidemic. It's a conversation that we need to have. People need to understand how our brain works so we can actually retrain our brain and go back to nature's treats. Then we can regain control of our health and weight. And it's a key principle of of that IWL plan that we've talked about before when you're trying to lose weight long term.
Dr Rupy: Yeah, absolutely. I mean, we didn't get on to talk about the the intrauterine environment and how that significantly impacts a child's risk and propensity toward obesity, diabetes and high cholesterol. So we'll probably have to park that for another time. I'm always getting asked about pediatric nutrition and, you know, what things can you do for kids and creating a healthier generation for the future. So we'll definitely have to chat about that some other point. But Nick, this has been super, super fascinating and I think it's going to be super impactful for a lot of people. What are you up to going forward? I mean, you've still got the program that's going really well. What do you see is on the horizon for weight loss and weight maintenance according to the research that you're doing and what you see on the horizon?
Dr Nick Fuller: Yeah, a lot of our work is is improving the technology of the online program so that we can help people form these habits. Remember, food addiction is one part of the puzzle. You've also got the sleep, the types of food we should be eating, how to incorporate exercise. Yes, so it's improving that so it's a scalable product that people can follow in the palm of their hand from all over the globe. But also being able to educate our next generation. So a lot of our work now is is working with parents, educating them on the principles of the IWL plan and setting themselves up so that they are surrounding their kids in these healthy lifestyle environments because this is what it's all about, making sure that our next generation are empowered so that they have control over their health and weight. Because otherwise, yeah, it's it's not looking good. I mean, the obesity epidemic is unfortunately only getting worse in a lot of developed and developing countries. So, yeah, a lot of my work now is is on about educating parents and instilling that education into our next generation, everything from, you know, the toddlers, children, adolescents, teenagers and later years.
Dr Rupy: Yeah, absolutely. I mean, that would be a great chat. Yeah, no, I think so. And hopefully, if we're, you know, I am meant to be leaving for Australia in like three days. So hopefully we do get to have that Tim Tam and coffee over a walk. I'm looking forward to it. Yeah, that would be really fun. I'm really looking forward to that. But thank you once again for your time and I wish you success with the program and I'm sure we'll connect again on the podcast or in person.
Dr Nick Fuller: Yeah, thanks, Rupy. I really very much appreciate you having me on. Keep up the great work. I'll continue to follow, yeah, everything that you do. So thank you.
