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Sigma Nutrition Radio
#612: Does Sweet Taste Exposure Actually Develop Preference? – Prof. Katherine Appleton
00:42:37
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- [00:00]
A
Hello and welcome to episode 612 of Sigma Nutrition Radio. My name is Danny Lennon. You are very welcome to the show. Today we're going to be taking a look at a really interesting and often misunderstood question. Does exposure to sweet taste actually make people prefer sweetness more and then go on and eat more sweet foods or struggle to move away from consuming them? Because this is an issue that comes up a lot in nutrition discussions, particularly when we're talking about sugar or low calorie sweeteners and their effects on diet quality. But many of those claims set on a number of assumptions that may not be necessarily as solid as we sometimes think. And so, for example, we've all heard conversations around the use of low calorie sweeteners or beverages that use non nutritive sweeteners. And the common claim is that, well, we shouldn't be using these because it accustoms people to consuming this sweet taste. They therefore build this preference and they won't be able to go and consume, let's say, normal drinks like water, or they won't be able to have meals that aren't really sweet because they've built this preference for sweetness and therefore their overall diet quality will suffer because they've been accustomed themselves to having this sweetness around? That's a very common belief. That may make some sense, but again, it's built on a number of different assumptions. There's some work that has looked to test these and see what do we actually know about preferences to sensory characteristics like sweetness, how does that connect with exposure to them and then more so how does that impact our overall intake? So to try and unpack the evidence in this area, I'm going to be talking to Professor Katherine Appleton from Bournemouth University in the uk. Professor Appleton is a psychology researcher whose work focuses in on healthy eating as a behavior, including food choice, taste preferences and then those factors that influence what we consume. So in this particular episode we're going to focus in on sweet taste exposure. Concepts like sweet liking, the role of low and no calorie sweeteners and how that fits into this picture. Concepts about sensory specific satiety. And then overall, what does the current evidence tell us? What does it not support? Where are some of those gaps? And then from that position, what pragmatically can we conclude around this exposure to sweet tastes? I think you're going to find this really, really interesting. There's some excellent work done in this area. I will link to some of that in the episode page which is linked in the description box where you are currently Listening so you can get more resources related to this topic there. Also, if you are a premium member, you will get a set of detailed study notes that covers everything that we discussed today with more detail, clarifications, explanations, diagrams, etc. That will be over on the episode page which is again linked in the description box or you can find it inside your members dashboard. For those of you listening on the free public feed of the podcast and are interested in getting more resources that help you really learn and retain more from the podcast listening that you're doing, then maybe consider becoming a Sigma Nutrition premium member where you get these detailed study notes, fully edited transcripts, as well as a premium exclusive episode each month. All of the information about that membership, how it can potentially help for you see if it might be a good fit for you. All of that will be linked in the description box where you're listening right now. Or you could just go to sigma nutrition.com and find out more there. And of course any of you that do consider becoming a member and joining us here, you are very much welcome and a big thank you because it is the direct way that supports the podcast helps us keep this going. And as we rely on our premium subscribers as opposed to external advertising etc. You really do keep this podcast going. So thank you. So with all that said, let's dive into this conversation between myself and Professor Kathy Katherine Appleton. Very big welcome to the podcast to Dr. Katherine Appleton. Thank you so much for taking the time to come and join me on the podcast today.
- [04:34]
B
No worries.
- [04:35]
A
I think as I've mentioned to you, I've been thoroughly impressed with some of the excellent work that you and your colleagues have done. And I think it's in an area where, as we will discuss, there is a lot of maybe confusion or at least some of the popular narratives or beliefs or assumptions people have in this area and I'm really looking forward to discussing the work that you've done. But before getting to any of those details, maybe just for people listening, could you give them some context to the work that you do, your research interests and anything else that might be useful for them to know.
- [05:04]
B
Thanks first of all Danny for inviting me. It's always nice to be able to tell people about what we're doing so they can appreciate it more fully. My name is Catherine Appleton. I'm currently based at Bournemouth University in the uk. I'm a psychologist by background. My interests are very much in healthy eating and essentially healthy eating as a behavior, so behavioral choice more so than nutrition or kind of the benefits of certain foods. I do have a little bit of nutrition background as well, so I kind of sit very clearly in the middle with a leaning towards behaviour and I'm
- [05:38]
A
sure that will come up with much of the work that we mentioned. And indeed I could have maybe asked you about a whole range of domains, because there's a range of different domains that we maybe don't have time to get to today that are particularly important and pertinent. But one that I wanted to start with has been some of the work you've done in around sweet taste, maybe sweet preference. And some of the work that I think has been really useful in at least testing some of the assumptions that I've found to be quite common, not only generally in the population, but even within nutrition professionals or academics. And in particular there is a maybe an assumption or a line of thinking that if we have exposure to some type of sweet taste, we're going to develop a strong preference for that said taste that in turn is then going to give us this reward when we have these foods is going to increase our intake. And so those types of arguments end up having this almost causal chain from exposure to sweetness to end up consuming more through that kind of sequence. Can you maybe talk about from your perspective and even from an overview, at least at first for you, in that type of chain I've laid out of this sweet exposure to having a sweet preference to then that impacting things like reward or intake. What do you feel are some of the maybe assumptions that are built into that may not be as solid or taken for granted as some people may initially assume.
- [07:03]
B
At least I think the idea that increased exposure to a certain taste and sweet taste here leads to an increased preference for that taste is a fundamental assumption that's not correct in the first place. I think that's going to be the biggest assumption. We have work now where we've looked at a number of studies, combined them together in a systematic review meta analysis to demonstrate that essentially your exposure to sweet taste doesn't change your generalized liking for sweet taste. So at the moment there is no causal link between sweet toast exposure and sweet toast preference. What's interesting though is, and this is where it can be confusing for certain flavors, there is possibly this causal link. So the more you experience a flavor, and there is a lot of work demonstrating, for example, that increased experience of vegetable flavors can lead to vegetable preferences for that vegetable flavor, there is some evidence there that exposure is important. So we need to be careful if we're talking about a flavor or A more generalized does this transfer to other flavors or other foods?
- [08:13]
A
And yeah, and there's a lot of really useful stuff within that. And certainly this will circle back to a topic I'll maybe bring up a bit later on when we talk about some things related to artificial sweeteners or zero or low calorie sweeteners. I think this is particularly pertinent. But from the initial opening, what you said, we're talking about in the context of sweetness and a preference or a liking for sweetness. One of the things that I noted in one of your publications, I think it was a 2024 paper, was being very explicit in trying to be clear on this terminology, which can sometimes get mixed up when people are talking about sweet liking versus maybe a phenotype of being a sweet liker and then sweet taste intensities. Can you maybe distinguish for us some of that different terminology where there's some confusion and what distinctions we need to make before we even enter into this conversation?
- [09:04]
B
There's a lot of different terminology that's largely based in sensory science. So yeah, not in psychology. And I'll say out front as well. I am not a sensory scientist, but you can ask people whether they like a taste or like a product and they can give you an answer. They might not. This is a slightly different issue, but they might not consistently give you the same answer. It's a question that you might have a little bit later. People, however, in general can say I like this product or I like this taste. Different individuals will have different preferences for that same product or that same taste. Preferences can change dependent on the intensity of the taste. So somebody can say I like the taste of this product X amount or I like the taste of the I like the amount of taste in this product X amount, if that makes sense. It's about the intensity of the taste. And certainly for sweet taste, we know some people like a really strong sweet taste. Some people like a less strong taste. They like the taste the same amount that the strength of the taste is lower. For some people it is an important distinction. There is also this issue of sensitivity. Some people of course, are just simply less sensitive. So they deck a certain amount of taste is in a product and it will taste more or less sweet to an individual because they just can't sense it.
- [10:26]
A
And that raises a really interesting point because you've outlined that that even within a liking for sweet taste, when we look at things like that intensity, that certain people may have this increasing liking for that as the intensity increases. Whereas if I'm picking up correctly. Other people don't see that kind of linear increase with intensity sweetness. It kind of maybe flattens out or even maybe a negative relationship at a certain point for you, when you see that type of variability in those findings, can we say that they are clear stable phenotypes? Is this something that can change or is this just measurement that could be playing into what we're finding here? That is to say, how clear is that variation that we're picking up?
- [11:09]
B
There is a terminology sweet like a phenotype, which certainly suggests this. It is a fixed stable characteristic. And yeah, some people. So the idea is that there are sweet likers and those individuals, as you say, they like the stronger their intensity of the sweet taste, the more they like it. There are sweet dislikers where the relationship goes the other way. So the less the intensity or the lower the intensity, the more they'll like it. And the majority of people are considered to be in the middle where they kind of have a U shape like sweet taste up to a point. And then at a certain point it becomes less liked. There is a suggestion that essentially everybody is a U shape, just that the shift, the peak shifts. So for some people it's really, really low and you tend to get this just the downward pattern. For some people it's really, really high and you just see the upward pattern. But in general, the thinking is that it's a stable characteristic. But in actual fact, there's increasing data coming recently suggesting that no, it isn't, this pattern can change. But you kind of picked up yourself, is this a measurement characteristic? Because the way we typically measure sweet liker status is very crude. Often these measures are taken using sweetened water or aqueous solutions, which isn't anything anybody usually drinks and there's value there because then of course their experiences or their previous experiences will have less of an impact if it's a food they don't usually consume. How generalizable that is that or how relevant is that to their actual food consumption is a very different question.
- [12:46]
A
And I guess even just from a research perspective that if people haven't thought about it, that is a really difficult research question to, to address, right? That when we see this variation in some of those outcomes in terms of liking in this particular case, being able to go from there and have real confidence that what we're seeing is a true variation in this response, this particular treatment is very difficult from based on just data points in a study that we're seeing variation, these outcomes might not necessarily mean that all of that has been causally dictated by these preferences. And so from the perspective of you guys doing this work, it's incredibly challenging to try and get to those types of conclusions. Right?
- [13:29]
B
Yeah, for sure. And that's. Yeah, I mean, particularly in relation to this exposure later preference, we've done a few studies on that now and they do you need to be doing randomized control trial type studies where you can more easily infer some level of causality. If you vary random or assign people to a certain level of exposure and look at their changing preference afterwards, you have more confidence. But as you say, so many things will be affecting not just their preference, but of course their perception in the first place.
- [14:06]
A
I think probably for those of us that come from more of a strict nutrition background, maybe there's an underappreciation sometimes of all the things that go into, into those food choices and preferences and so on that I think is really well captured in, in the work that you've done. So even when we're talking about something like a preference, we tend to maybe resort straight away to the actual characteristics of that food and how biologically a human might interact with that. But of course that's only one part of why someone may develop preferences or liking towards certain types of things. From that perspective, can you maybe give us an idea of the type of factors that can influence to see how wide this actually could be?
- [14:51]
B
There's a whole range of more psychological factors that can impact more how much people consume. So what you're really talking about is the difference in the real world or in a public health sense, why do people consume the foods that they do? It's not just because they like them. Of course not, but there are, interestingly, in the sweet taste world there are a lot of attitudes towards sugar will impact how much you consume. Attitudes potentially towards low calorie sweeteners, not just how much you like them, but also how hungry are you right now, what's available right now. There are so many different characteristics that can affect what you choose to consume. What you perceive may vary less, but what you perceive is also affected by a whole range of different characteristics as well.
- [15:42]
A
So far you've noted that we have this at least assumption that needs to be challenged around whether just exposure to something like sweet taste then leads to a true preference that again is going to influence our intake of that over time. And then when it comes to this concept of these various different phenotypes around being a sweet like, like or not, there's maybe still some open debate there of how much of that is set and how come it can be changed. I'm wondering here how this relates to some of the work done on other characteristics not to do with sweetness, where food preferences are developed and specifically how this differs maybe between that early developmental stage in children where maybe we learn a lot of preferences around food generally versus in adults. And so when it comes to sweetness, do we see a distinction here in that literature of how this plays out between children or adults that already have a set preference for sweetness, let's say, or liking, and how that might be changed or not? How do we untangle this type of distinction?
- [16:47]
B
This is a very interesting question. The work that I've done has been all in adults. Well, in relation to sweet taste, anyway, I know there is work that's been done in children. And again, this would suggest that exposure has very little impact on preferences. You're right. Logically there ought to be more room for a change in children whilst they're developing. There is the possibility that there might be sensitive or critical periods during development where taste preferences change very, very early. And then at the stage where humans are learning to eat solid foods, there's room there. Then again, there's a possibility, while there's some suggestions that preferences may change with hormonal fluctuations around puberty, but yeah, there's, to be honest, very little work. There's very little work in all of these age groups, to be honest, including adults. The issue though is always the same. Essentially, if you're looking for causality, how long do you need to study people for? What's the time period over which these changes might occur? And also there were questions about does it matter? Is it frequency of consumption of a food or taste that's important? Is it the total amount of consumption? There's all sorts of. Yeah, all sorts of kind of nuances in the. More the exposure side that can also have impacts in the work. Typically, I know the vegetable work better than any other, but yeah, in the vegetable work there are suggestions that yes, you can encourage children to like the flavour of a vegetable and consumer more that vegetable, but these are effects found in very controlled studies under very controlled exposure scenarios. And also they don't tend to last, so they'll last for six months, a year, but beyond that. So there is a question about kind of duration, duration of exposure, duration of effect, but then also potentially it's not just about duration, but something else, some other developmental characteristic goes on in your window and that could have an impact as well.
- [18:55]
A
I did want to pull back to something you mentioned and maybe we can clarify a bit more terminology for people because I think this is important when we're thinking about a number of terms that oftentimes loosely get related to food reward. But there are maybe distinct concepts under that umbrella. And so, for example, sometimes people are talking about pleasantness of a food in a true sensory aspect. Right, the sensory characteristics of this food. But as you've alluded to, there's a number of these characteristics that are more on that psychological aspect. Right. So where we come into something like wanting in a motivational sense, this motivational wanting, can you maybe distinguish between those? So when we're thinking about things like the pleasantness of something versus someone's actual desire or motivation to eat something, how in a research setting at least, we typically would classify those.
- [19:46]
B
You're right, they are very different concepts. Unfortunately, the terminology used to refer to them isn't universal, but they do broadly fall into two characteristics or two classes. You've got, yeah, liking pleasantness, essentially a characteristic of the food. And then you've got more a motivational desire reward type idea. I think the way to think of them as two different things or the easiest way is to think if you consume any food, if you, yeah, think of any food product and you can say, I, I personally like food, I like chocolate, but if I think about, if I'm extremely full at the end of a meal, I might still like the taste of chocolate, but I don't want it. I don't want to consume it there and then. So I think that's kind of the distinction for a lot of the time in the real world, we like foods and we want them kind of at the same time. When you're hungry, you can imagine you pretty much want any food, but you could still probably say, oh, you know, I want to eat something, but I don't really like this food, it wouldn't be my choice. So there is a distinction. I think people can make it in themselves if you ask them and if you say to them, do you actually like it? Do you actually want it? And then people can start recognizing the distinction. But yeah, it's a general. Unless you sit there and think about it.
- [21:09]
A
One of the things I wanted to ask you about, and this I suppose from a research methodology perspective is really interesting, is that when it comes to the measurement of some of this in this area, we can have there's a whole variety of different study designs and maybe they're answering different research questions, but it's not uncommon to see work that maybe preferences or has a preference for using let's say a sucrose solution, because we have this kind of really clear sensory stimulus that we can measure quite precisely. Then there's other work, and I've noted some of the really excellent work your group has done of attempting to look at actual, maybe real foods and real meals that people might be consuming, because we have something that's much more ecologically valid. And so when it comes to this, can you maybe talk about the, the weighing up of what we can take from each one of those? And for you, where what might be more informative for the types of research questions that we ultimately care about?
- [22:06]
B
With this question, the advantage of the more controlled stimuli, like the sugary water. It's not something people experience on an everyday basis. So you're avoiding any effects that might be due to expectations or familiarity or previous history. Whereas by using any novel food in actual fact, you get rid of all those potential effects. And people do do studies not just with sugary water, but they're called model foods. They're foods that are not real and have been created purely for the purposes of a study. At the other end of the scale, you've got foods that are publicly available, commercially available, and you're looking at how much of these foods do people consume, how much do they like them, how much do they choose to consume from a personal point of view? The second is by far the more informative. All of the work that we do at the end of the day is trying to improve health, and health will only be affected by the things you actually consume. If you have, you might like something and never consume it, and it's never going to affect your health. So the disadvantage of the real faints, though, as you say, there's 101 things that might also be impacting whether you choose to consume that food, but there's 101 things that might also affect whether you like it.
- [23:21]
A
With that in mind, I did want to return to what we mentioned at the start, the issue around low or no calorie sweeteners, because this is where, or at least one of the examples where I most commonly see these types of assumptions built in. Sometimes people state it with much more confidence and sometimes it's more of a hypothesis. But nevertheless, the narrative is pretty similar when they're trying to maybe discourage people from using artificial sweeteners on the basis of being exposed to a sweet taste. And so the line goes that, well, if someone is now consuming artificial sweeteners in terms of like a diet drink, like a Diet Coke, or is having products that are artificially sweetened but don't have sugar or have much less calories. What we're still doing is we're getting this person to like the sweet taste and they'll never be able to then choose foods that don't have the sweet taste. And so we're going to be negatively impacting their overall diet quality. And I think this is a widely had belief enough that require some discussion. So I'm wondering from the work that we actually have in this area and some of the data that can maybe speak to this, what do we know about this potential question of something like a low or no calorie sweetener being something that just maintains this sweet preference that someone can get away from and what might be the most accurate or evidence based way to think about what is actually going on?
- [24:47]
B
This is a great question. It is very much a current public health debate. The majority of the work that's looked at exposure has not distinguished between whether that exposure is a result of sugar or low calorie sweetness, as you say, or fruit as well. Also a source of sweetness, of course. And all of the work, regardless of where the source of sweet toast is coming from, is really suggesting that this exposure isn't impacting on subsequent preferences. So there's no reason to really suggest that low calorie sweetened products will specifically cause that effect. Yeah, there's. I don't know off the top of my head, I don't know any studies that have looked specifically at does exposure to low calorie sweetened foods in a controlled sense or in a kind of randomized study impact preferences? The effects are not there for sweet taste in general. If sweet taste comes from all sorts of sweet foods. So sugars as well as. Yeah, low calorie sweeteners. An interesting question and I will have a look and see if I can find that. Actually it's an interesting question at the moment. This idea though, that low calorie sweeteners might have a similar impact on preferences as sugar. There are many countries now around the world where they're restricting low calorie sweetened beverages or taxing low calorie sweetened beverages in the same way that sugar and beverages are being taxed to try and reduce consumption and preferences, but really don't have the evidence for those policies at the moment anyway.
- [26:23]
A
Yeah, and this is why it becomes such an interesting debate because on a purely research side, as a research question, it's really interesting for anyone to consider because we would like to have a bit more data to answer some of these specific questions. But from a public health perspective, this becomes really important because as you've noted, we're starting to see policies now being introduced that aren't actually based on solid evidence. Now maybe we'll find something, but as of right now, they're not based on solid evidence. And not only that, it's that there could be a relatively significant downside given the fact that we could make the case that by using some of these types of products, we're at least giving some people a tool to move from sugar containing drinks and products to these now sugar free versions, which we would certainly hypothesize would have a benefit. And now so if we end up taxing these and having the same effect on removing them, maybe we're taking away an otherwise useful tool to reduce overall sugar consumption. So we have this interesting debate that's playing out within public health. But the problem, as you've alluded to, is that we don't really have evidence to base some of these policies on.
- [27:35]
B
No, we don't have that evidence at the moment for low calorie sweeteners. I think it is coming, to be honest. I'm aware of some trials underway, but yes, we're currently doing some work as well to look at essentially do low calorie sweeteners have this value that you're suggesting that essentially they allow people to maintain the sweet taste of their diet if that's their preference, if that's what they want, without necessarily consuming sugar. So we certainly have a trial going on at the moment and we're doing a systematic review where we're looking at essentially does low calorie sweeteners versus an unsweetened product in a trial. So low calorie sweetened beverages, for example, versus water, does that change dropout rates, acceptability of the diet, dietary profiles in general? Because there is some work as well that suggests low calorie sweetener consumers tend to have healthier diets.
- [28:28]
A
There's two directions to look at this as well, right? The situation of someone who maybe currently consumes quite a significant amount of added sugars within their diet and maybe is replacing some of that with now some low calorie or no calorie sweeteners is reducing that, but is maintaining some of that sweetness for palatability purposes. Then we have the other where maybe there is people get worried that someone who has maybe typically consumed water or non sweet products and drinks and then warning them, don't start consuming something that has artificial sweeteners because you will just get used to Consumers having sweetness. And maybe there we have a bit more to say because that might relate to what we let off this conversation on around just being exposed to that sweetness doesn't necessarily therefore follow. Someone will develop a true liking or preference for that.
- [29:18]
B
No, I think that's right. And yeah, there's. I also think it's relatively unlikely, to be honest, that there's going to be, or certainly there's going to be a large proportion of the population who currently drink water because presumably they prefer water and we'll suddenly switch on to low calorie sweetened beverages. I don't think anybody's suggesting it will have benefits other than its sweet taste.
- [29:41]
A
One thing that I did want to ask about is another concept that sometimes comes up when we talk about some sensory characteristics of food that maybe relate to the food reward, et cetera, that might play a role here. And that's around sensory specific satiety. So this concept that not only do we have this kind of satiety in general, but that could be related to the specific sensory component we're talking about. So someone might have, as they continue consume a meal, let's say they are less motivated to continue consuming that as they. They do. But then if we switched that from their typical a dinner meal and now suddenly dessert comes out because the sensory component is so different now, it's almost like a reset on their satiety. To very much oversimplify this explanation, but the reason I bring it up is I'm wondering from your perspective, does this relate to this discussion around sweetness and particularly this assumption that, this flawed assumption that you've outlined that just having exposure to sweetness is going to prime someone for future sweet intake. Because essentially the sensory specific satiety would be saying, well, if we're consuming one type of thing like something that's very sweet, then changing to another, at least in that meal or in that moment, would be the thing that would drive more intake, not more sweetness?
- [31:00]
B
Yeah, very limited work that suggests sensory specific satiety is not as strong for sweet taste as for some other tastes. But the majority of work will suggest exactly the same. So if you consume sweet products, then you'll, and then you're offered a whole range of different products or different tasting products you're much more likely to consume than non sweet ones. Having just consumed sweet products. There is actually a really nice study where individuals were asked to consume for 24 hours either a sweet diet to everything sweet, or a non sweet diet or a mixed diet. And then the 24 hours run from Lunchtime to lunchtime, they were given the choice of whatever they wished to consume for the lunch afterwards. And exactly as you would suggest from sensory specific satiety, those who'd been on a sweet diet for 24 hours didn't want the sweet foods at the lunch and vice versa. So those who are on the non sweet diet were the ones who were choosing the sweet foods at lunchtime.
- [32:02]
A
Before I ask a bit about some of the practical and clinical applications of this from purely a research perspective, and you've alluded to some of these already. What for you are the most pertinent open research questions that hopefully we can get some answers to in the coming years. With research to follow. What are those key yet to be answered research questions that you would like
- [32:24]
B
to see answers to from a practical point? First of all, I think we really need a lot more evidence on low calorie sweeteners. As you say, people are making policies without the evidence there. So we do need the evidence. What are the harms? What are the benefits? Proper open studies where we really are open to the possibility that there are benefits as well as harms, they do need, or instead of homs, they do need to be randomized trials where people are asked to consume the product. So it's not about who's choosing to consume the products of their own accord for long enough periods as well. Where we can actually see changes. From a theoretical point of view, what I personally think is really interesting and where we, again we don't have the evidence yet, is essentially where or how taste preferences really develop in the first place. Where do they come from? If there is such a thing as a phenotype, where some people like more intense sweetness and other people like less intense sweetness, where does this come from? There is some work on this looking at genetics, but the suggestion is that preferences and perceptions potentially are maybe about 40% genetically determined. And we know there are genetic bases for some tastes, bitter taste, particularly hostage genetic background. But yeah, where these, if they don't come from as a result of exposure or yeah, where do they come from? Or in reality it's going to be a lot more nuanced. So yeah, from a theoretical point I think that would be so interesting but exceptionally difficult to do. And I think this is the problem.
- [34:00]
A
Having some of that data would allow us to be more clear in essentially helping people. Because right now there's a lot of times we're trying to do this on some of those flawed assumptions we mentioned earlier that are based on, let's say exposure is the issue. So let's reduce exposure and we could be just completely wasting our time until we work out what those actual mechanisms are. And so with that in mind, and again, I'm very wary that as you've outlined that you are coming from a psychology background, you are working at academia and you are not maybe for good for you that you don't have to deal with this as a dietitian maybe would, but there's certainly many dietitians or nutrition professionals listening that are in a kind of dilemma when it comes to this that they have. That example we gave earlier of someone who maybe needs to reduce their overall sugar consumption is doing that with the help of a nutrition professional. And then the professional maybe has a couple of avenues we can go down and there's different people will have different preferences. One will say, well I want to make sure this person can preserve the palatability of their diet so it's easier to adhere to whilst at the same time reducing these added sugars. So I'm going to be more in line with keeping that palatability and sweetness the same and maybe using things like products that contain non nutritive sweeteners. The other person might say, well I've heard about the sweetness being maintaining this person's preference, it could negatively impact their overall diet. So I'm going to aim to reduce that sweetness by advising them not to consume things that are sweet. From your perspective, what would be some of the things that they should consider that we can actually take from the current evidence base that might be useful in that decision making?
- [35:42]
B
Something that I need to clarify actually Demi, that their health implications are due to added sugars, not sugars in general. And I think this is something we really need to be clear about. It's very easy to slip into talking about sugars instead of added sugars or free sugars. The health implications are all about added sugars and free sugars, not sugars in general. So I do think there's a massive space here for fruit and seems to be getting sidelined a little bit. Some consumers particularly get confused about whether fruit counts as a sugar or a non sugar diet. Can I consume fruit? Can I not consume fruit? And yet there's a lot of health benefits to consuming fruit. For your two kind of people who want to reduce their free sugar intake. One wants the sweet taste and one doesn't really mind the one who does want the sweet taste. We have no evidence for recommending it against sweet tasting foods for preferences. So if that individual wants to consume their low calorie sweeteners, that will be absolutely fine. That will have no impact on their preferences. Whether there are other issues to do with low calorie sweetener consumption is a different question. But as far as preferences go, no issue. And you see, this is the point that we've already made about palatability. If by consuming low calorie sweeteners, they stick to a more healthy diet or stick to a diet that's lower in fruit sugars, that's going to benefit their health. For the individual who's not too sure or doesn't mind low calorie sweeteners versus not at the moment, we have no evidence to suggest a difference between low calorie sweeteners and unsweetened foods or beverages for preferences. So, yeah, they can choose to consume as they wish.
- [37:23]
A
Excellent. So a number of times we've talked about this maybe misconception that there is out there, that simply having exposure to sweet taste, therefore, is going to lead to a preference for sweet taste, and then some of the consequences of that. Beyond that, when we're talking about this general area around taste preferences, food reward, or even with sweetness in particular, are there any other maybe misconceptions that you've seen or that tend to be relatively common within nutrition discourse that if you could correct or at least have people be more wary of the nuances of the terminology, what was some of those misconceptions where we need to be a bit more careful?
- [38:06]
B
I can make myself really unpopular here, Danny. There is no evidence that sugar is addictive. There is no evidence for cravings for sugar, not in a scientific sense. It will be something that some people don't want to hear, that there's no evidence, and I think there's something there as well, that's very valuable, particularly for professionals to understand. If people are coming in and saying they have an addiction, I don't disbelieve for a second that people have strong preferences or strong urges. But yeah, there is nothing to suggest that sugar will be addictive and certainly not sweet foods either.
- [38:41]
A
An excellent and important clarification, I think, for many people. So, Dr. Appleton, before we get to the very final question, for people who maybe want to maybe look at some of the work that you and your colleagues have done or keep up to date with what your group is doing, is there any places on the Internet you would send their attention towards or anything you would point them to if they are interested in doing so?
- [39:04]
B
I am on research gates, so all my work will be on research gates. In normal academic databases I'm there on Google Scholar.
- [39:12]
A
I'll make sure to put a list of your work that most directly relates to our discussion today. And then people can go from there in, like you say, research gate or PubMed and find more of your more broader work. So with that, Dr. Appleton, we get to the final question that I always end the podcast on, which can be something completely outside of what we've discussed today. So apologies for putting you on the spot with what is quite a broad, open question, but it's simply, if you could advise people to do one thing each day that might have a positive impact on any aspect of their life, what might that one thing be?
- [39:46]
B
Oh, I'll get outside the box and say, do more exercise. Despite working your food, I think exercise has a stronger impact on people's health or activity.
- [39:56]
A
Certainly not going to disagree with that. An excellent recommendation and an excellent way to round this out with that, Dr. Katherine Appleton, thank you so much, first of all, for giving up your time. Second, for the great information you've shared, and then more importantly, your excellent contributions to the field. They're very much appreciated. So thank you for coming and doing this.
- [40:14]
B
Thank you. Well, thank you for your interest and if any of your listeners want to contact us, please use my email. Always happy to hear from people.
- [40:35]
A
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