Nutrition Scientist: This is why you're confused about ultra processed food | Prof. Sarah Berry

27:28So there's no change in that example of what's in there. It's just the act of like breaking down these... I think about this like my school biology, like the cell walls and all this stuff being broken down into sort of this mush has suddenly completely changed the way my body's responded. And it sounds like in a very negative way, like the way you're describing it sounds like eating this as apple rather than the apple puree is much better for me. Absolutely. Because you're eating it more slowly, you're absorbing it lower down your gastrointestinal tract where you've got more fullness receptors.

28:01So you're feeling more full. you're allowing the time for the fullness of septic to say hey Jonathan you've had enough rather than this kind of like fast food so to say and I think if we bring it back to where we started this conversation around this dreaded term ultra-processed food there's some fascinating research that's just come out where they've looked at food texture which is what we've been talking about in relation to ultra-processed food and how that impacts our energy intake and our weight And what they found was that if you feed people ultra processed food, and this is according to that NOVA classification that we talked about, that soft, you eat loads of that, you eat excess calories from that, and you're more likely to put on weight.

28:49If you feed unprocessed, but soft food, you still eat that quite quickly. Could you give me an example? Oh, now you're putting me on the spot. it could be yogurt is a good example of an unprocessed soft food so you're still eating it very quickly because of the texture if you then have an ultra processed hard food you eat that more slowly and have less over consumption of calories even than the unprocessed soft food so it's a bit complicated but it's like this kind of if you think this step down where the worst in terms of the rapid rate of eating, the overconsumption is your soft ultra processed.

29:32Then the next step down is your soft unprocessed. Then the next step down is your hard ultra processed. Then the next step down is your hard unprocessed. So it is a little bit complicated. But what I'm trying to say is it's not all about whether it fits in this terminology of ultra processed food according to this NOVA classification. Actually, the overconsumption of the calories is more related to the texture which goes back to the food matrix rather than, oh, is it Nova 4, which means it's ultra-processed or not? I'm also struck that it took you a second to think about what was a soft, unprocessed food, which tells you that there's not that many of them in our natural environment, I guess.

30:16Yeah, I find this whole segregation of unprocessed and ultra-processed actually really hard. So I think, yes, it's partly that, partly because most foods in nature are quite hard. So I think you picked up on a really important point. But I would say if people ask me, oh, is this ultra-processed? Isn't this ultra-processed? I actually don't know. I've had 25 years training as a nutrition scientist. And I don't know. I'm so confused. And I shouldn't be confused. I should be able to tell you, oh, that's ultra-processed. That's bad for you. that's not. And it's because of the way that this classification system has been set up.

30:55And this is why we need to look at things differently. You've talked about added ingredients that can be bad and which maybe we weren't testing for in the right way up until now. So there's all these additives, some of which we just know are bad, and maybe we've allowed into our food for any reasons, but also things that maybe like sweeteners and things like this that we didn't know as much. But Jonathan, I think it's important to say, I wouldn't worry. No one should be worried that there are additives in there that are about to give them cancer. We just need to be more cautious that there's some that there's some evidence emerging that we should be trying to avoid.

31:30And there's others that we know are less problematic. And there's others that we know actually might even be beneficial. Okay. So we've got these additives and you're saying we shouldn't necessarily be like, oh, there's any additive that's immediately going to give me cancer. That's not the way to think about it. Then I think you said there is sort of the absence of healthy things. So this is like stripping out all of the nutrients that you would get from like a whole food that might be feeding my microbiome and my body in general, because I sort of ripped that out and then sort of doubling down on sugar and saturated fat and things that are bad.

32:08So that's the second part I think you talked about. And then you said, but hang on a minute, there's this whole thing to do with the structure of the food, which historically no one's really focused on. But we haven't been talking about it enough. Okay, this whole thing about structure and the difference between the food being turned into something soft versus something being hard, meaning that you're going to eat much more of it and you'll eat loads before you realize that you're full, but also that the grinding itself can destroy a lot of those nutrients. So it's not that in that case, they haven't necessarily been pulled out of the food, but actually just they've been smashed to pieces.

32:46So you're no longer getting the benefit of them. Yeah. So spot on, apart from the last bit, it's not so much that the grinding destroys the nutrients but it destroys kind of the properties of the nutrients so most fiber very simply put is plant cell warm material so has a really important structural role and so it has a structural role in essentially kind of slowing down the food so when it's intact it slows down the rate it's absorbed it changes where it's absorbed hence why fiber can also add this satiating this fullness effect to food if you grind the food basically you're breaking the fiber up so The fiber is still there, but it's not intact and it's not performing that magical role that it performs in that structural way.

33:28Got it. So it's still in there, but it's sort of like the, again, I'm thinking back to like my little school cell wall picture. It's like keeping everything safe inside and delivering it slowly, almost like a little pill, I guess, like when I take medicine, right? Like takes it, keeps it intact for longer. And you're saying I've broken all of those cells, everything is just open and my body digests it sort of instantly. and then my blood sugar goes through the roof and all of these sorts of things? Totally. Like imagine a water balloon, for example. And so you've got the rubber, you know, keeping the water safe inside.

33:59So that's just like the fiber is like the rubber keeping all the nutrients inside. And then you break that and everything comes out. It's like being hit by water balloons. I like this. So you took us up to this point. Is it all so complex that we're sort of doomed and it's impossible to sort of differentiate between any of this? So I think it is really complex. And I think it's a really, really difficult challenge to be able to differentiate between a good processed food, a really bad processed food and an ugly processed food. But this is what we've been working on with the team at Zuri over the last year and working on really hard, building on all of the science that we already know that's been going on over the last 20 years or so and using the fantastic database as well that we have at Zoe that kind of gives us that ability to be able to do science in a slightly different way than I would be able to do in my traditional academic setting.

34:56So we have this kind of goldmine of data that we can leverage in order for us to develop this kind of understanding and put it into something that's translatable for individuals. And so we've been working on trying to pull together the different features that you and I have just been talking about that we know processing impacts to negatively impact our health and trying to do that in such a way that we can then advise people on what foods are really bad and what foods aren't really bad. And these features include everything that we've just talked about. So it includes things like the additives, the emulsifiers, there's the colorants, but it grades them.

35:34A food could have 10 additives, but they could be all low risk. They could even have an additive like inulin, for example, which is fiber, which is classed as an additive, but actually it's healthy. Or you could have a food that just has one additive, but we know it's one that the evidence is starting to emerge that is negative for our health, negatively impacts our gut microbe. Yes, it won't give us cancer, but still we feel that it's not something that we should be having regularly. And so we wanted to create a system where firstly, we looked at these additives, these emulsifiers, these colorants, but graded them according to their predicted impacts on health, where you've got some baddies, you've got some in the middle, kind of medium risk, and then you've got some that are neutral.

36:18Then what we wanted to add in is something to be able to look at how that food matrix, that structure, the processing also impacts our health. So we've added in a measure called energy intake rate. And it's very much like a surrogate. So it's a way of looking at how the structure has changed. And basically, energy intake rate is a measure of telling you how fast you're eating your calories. So is that like your apples versus your apple juice and your puree? Exactly. So it's exactly like the apples and the apple puree, they would have entirely different energy intake rate your apples would have a very low energy intake rate your apple puree would have a really high energy intake rate which means you're going to over consume it which means you're going to consume excess calories and that is the biggest problem that we have we're dealing with a problem for the most of the us and most of the uk not everyone but internationally over consumption of calories for many people is a problem and so that's what we need to tackle with these processed foods where it is a problem.

37:19So we have the feature of energy intake rate and it's the surrogate at the moment for food matrix because it's not possible to tell exactly has every cell been broken down. This is a really good measure for us to use instead. And then we brought in a third measure and the third measure is something called the hyperpalatability index. What is hyperpalatability? So hyperpalatability is basically a term to describe it being too yummy, too good to be true. And so what we know is that in many processed foods, there's kind of like this magic mix of nutrients of, for example, salt and fat or sugar and fat that wouldn't typically be found in nature.

38:03But when it's added in particular ratios, makes that food so yummy that it bypasses these kind of sensory specific areas of the brain that would normally say, well, hold on, you've had enough. And so if you think of, I don't know, what's your favorite ultra processed food? Pringles. Okay. If you think of Pringles, they're salty. They've got lots of like really refined carbohydrates. So you can just eat and eat them. Like it isn't their advert. You can't. Once you pop, you just can't stop. I used to really like them. And now you ruined this for me over the last few years. But is that an example?

38:44So you're saying it's not just because it's soft. So it's not just that it's soft. So we're assessing the softness in a surrogate way with the energy intake rate. What we're doing here is we're looking at how yummy that food is in such a way that it's kind of tricking our brain to overeat it. so there's some research that's been done by external researchers over the years that's looked at a particular mixture of different nutrients that wouldn't be typically found in nature that we know seems to be associated with over consumption of a food so for example and i don't remember the exact proportions for example a particular cut off of salt alongside refined carbohydrate or a particular cut off of fat alongside a particular amount of sugar, for example.

39:34And when you say refined carbohydrate? So your Pringles is refined. So carbohydrate where the structure has been destroyed. So refined carbohydrate like white bread, for example. Oh, so this is where it's a carbohydrate, but once I eat it, it gets turned into sugar almost immediately. So really what I call a quick carbohydrate. I've heard this term bliss point mentioned before as like nutrition scientists creating this sort of bliss point between sugar and fat and salt. Is that the same thing? Yeah, so it's sort of the same. There's this idea that it activates these reward centers in your brain, that it gives you this kind of dopamine hit.

40:12It is, I need to caveat, as I always do, a new area of research. There are some skeptics out there about where the hyperpalatomy index is, you know, is there yet enough science to support it? But I think what science is out there to date is quite supportive of the fact that there does seem to be something going on that activates these reward centers that just means that you go on wanting more. There's very few people, I think, after having an apple that are left thinking, oh, my God, I just want another apple. I would say there's far more people that eat those Pringles of yours and say, oh, I would like a few more of those.

40:47I was thinking about, you know, potato chips or crisps as a great example. So I do really like those as I think about like one of the things. And I'm quite careful about trying to choose a healthier one. So it might just say like potato and some sort of oil and salt. So only three ingredients. But what's interesting is I can eat a really big bag. I wouldn't eat that many potatoes. I certainly wouldn't drink oil. And if it's salt on its own, it'd be disgusting. So it's something about the combination in just the right proportions that is making me just want to keep on taking it. And I do, right?

41:20You eat it really fast and it's delicious and you want more and more and more. Is that this hyper palatability? Yeah. So it's having exactly that, the combinations in just the right amount that hits those reward centers in your brain that leaves you wanting more. Let's say regular potato chips or crisps for those in the UK that quite often might just have potatoes, might just have oil and just a bit of salt. That's a great example. You've just got three ingredients, which individually are fine. But when you put them together, it becomes so delicious that they surpass your normal kind of fullness signals, that they hit those bliss points, as you call it, that leave you just wanting more and more.

41:59I think it's really interesting because I know that there's been a lot of stuff in the media from big food manufacturers, but also certain nutrition scientists pushing back on the idea that there is anything different about processed food beyond the fact that it just happens to be like junk food, as I was told as a kid, which means it's like it's got sugar in it, it's got saturated fat. So in other words, there's no difference between that and anything that was like a treat in the past. And I think what you're saying is it's not just the ingredients. It's not just whether or not it has sugar in it or that it's got sort of saturated fats in it.

42:42Actually, if you can design the product just right, you get this sort of combination of these ingredients that sort of overrides my natural tendency to say, oh, I've had enough. I'm a bit bored. I'm not going to eat that anymore. Yes. I think that's just one component. I think it's less important personally than the texture and the energy intake rate and less important than the macronutrient composition. So I think we shouldn't be too obsessive about this hyper palliative index, particularly given that we're still waiting to see more research about this. but I think certainly it's something that we need to pay attention to.

43:20So it's like one component in the overall understanding. Yeah, absolutely. So what do you tell all these scientists after all of that? We've developed this new score that we've been working on as a science team that takes into account all of these factors and it weighs these different features in such a way that it can categorize processed food into those good, the bad and the ugly. And I think for me what's most empowering about this, and this is a scientist that has hated the term ultra-processed food, hates the demonization of processed food, is that through the score that we've developed, we've been able to see in the US and the UK, it's not 65 % of processed food that we should be worried about.

44:04It's actually only about 20 to 25 % of the food that's on the supermarket shelves in the US, in the UK, that is actually processed in such a way that it's quite bad for our health. I'm guessing that in your science thing, you don't call it ugly processed food. How does this end up being categorised? So we've generated a scale and this scale goes from being high risk to medium risk, to low risk, to no risk. And so what we have is this incredible food database where we've got millions of foods that are in our food database that are at brand level. And if you remember when I talked about peanut butter, it's really important to think of the brand level, i.e.

44:44the Reese's peanut butter versus the Sun Pat versus the Pippa nut. And are they all the same processed food risk? Absolutely not. So the Reese's would come in at high risk. The Sun Pat comes in at medium risk and the Pippa nut at no risk. And so we have millions of foods that we're funneling through this pipeline that we first categorize them according to, okay, what additives emulsifies, colorants are in them are they fine are they ones we should be a little bit more concerned about then we look at what's their hyper palatability index then we look at what's their energy intake rate is that surrogate of that matrix and then these foods fall across this classification system across being whether it's high medium low or no and i think the best thing that's come out of this is the fact that we're not demonizing every packaged food out there and that also we're enabling people to make choices that are informed based on the predicted health effects across food groups.

45:43So for example, someone could go into a supermarket and could look at breakfast cereals and they could say, okay, my kid likes Coco Pops and that would, I assume, would come up at high risk. But I could scan and look at other kind of chocolate covered cereals and it might be that There's ones that are very similar, but actually coming up at low risk because they have different additives or they have different energy intake rate. And so I think having this kind of tool is really empowering for people to make healthy choices. But for me as a scientist, it's really exciting because also now we can move forward this science on how food processing impacts our health.

46:21Is someone you know trying to make healthier food choices, but potentially getting confused by misleading food labels? Perhaps they're struggling to know what's truly healthy when they're surrounded by food that makes claims that it is, even when it isn't. If so, why not share this episode with them right now to help them understand what healthy food really looks like from a world-leading nutrition scientist? What is the response that you're getting from all the scientists as you're describing this? Because it sounds like you're saying, in general, none of them like this idea of the word ultra processed, how are they responding to this idea that there is really an issue around processed food, but it's more complex?

47:02So this is what scientists love to hear, that it's more complex. And so if it's a scientist, we're agreeing with other scientists that it's more complex. Absolutely. And I think that it's the oversimplification. It's using a classification that's based on the extent rather than the impact on health of processing has been the real problem. And I think it's also the fact that we're not demonizing all the food because the pushback there is in the nutrition community as well around the term ultra processed food, in addition to the fact it's using a classification system in the past that is pretty rubbish or not for the purposes of looking at the healthfulness of the food, is the fact that we have to recognize that many processed foods out there are significantly cheaper.

47:46And there's been modelling work showing on average they're 50 % cheaper than the unprocessed equivalent within the same food group. So if you take an ultra-processed bread, for example, versus an unprocessed bread, that there's about a 50 % price differential. And that's really important to acknowledge that because many people therefore don't have the budget to make the healthiest choice. And that's what I think is really empowering about having a tool that's not demonising everything, that we're saying, OK, there's a particular problem with this 20%. See if you can avoid it. if you can't having it now and then isn't going to be a major issue but try to make sure that the majority of your diet is not heavily dependent on that and I think it's also recognizing as well there are some things that are added into food for a reason we need to keep our food stable we need to keep our food safe there are additives that are added in to keep our food safe or stable we don't want to all be going and getting E.

48:42coli or some other kind of illness. And so there's some things that are put in food for a reason beyond just to make that food more tasty. And so we need to recognize that and not demonize all of that as well. I feel that on the one hand, you're saying don't demonize everything that's been viewed as sort of highly processed or ultra processed. On the other hand, I think you're saying that 20 to 25 % of the food that we're eating is high risk processed food. So if I look at it on that side, it seems like at the end of this research, you're also saying there is a real issue. Yeah, I think that I hope that very few nutrition scientists would ever say there is not an issue with the food that people are eating or the majority of people eating, the food that's on our supermarket shelves.

49:30I think that what nearly every nutrition scientist would agree with is that we're not eating enough fiber, we're not eating enough bioactives like polyphenols. We're eating too much salt. We're eating too much saturated fat. We're eating too much sugar. I think that also most nutrition scientists would agree that there are many processed foods that are processed in such a way that are not good for us in addition to how that composition is affected. And this is what the score that we've created is trying to capture. If we're putting something out there as scientists, putting something out there that people are going to use, it has to be right.

50:09So one thing that I am really proud about in relation to this ProSixal score is it's part of a bigger score, it's part of a bigger food score and it's part of a bigger picture of how we need to look at the healthiness of food. So we've created an overall food score that considers multiple features of what shapes the healthiness of that food. How much fiber is in there? How much healthy fat is in there? How diverse the plant-based ingredients are, how little salt is in there, how little sugar is in there. So all the kind of features that we know are really important. Some of the very traditional features, some of the more novel features like the quality of the fat rather than the type of fat.

50:46And the processing score is one feature of this overall food score. So when someone looks at the healthiness of something in the supermarket, for example, so like the peanut butter or any food, Firstly, they're getting an oval picture, not just of the processing, because the processing tells us only a small part of that story. So if we take beef tallow or butter or lard as an example, they're not classed as processed foods. But hopefully everyone listening will know they are bad for you. They're packed with saturated fat. They're not good for you. And so we need a score that captures not just the processing, but also the overall healthfulness of a score.

51:24so we have the score that captures the overall healthfulness of the score using all of the science from the last you know couple of hundred years plus one feature of that is our processing score and that's what gives me confidence as a scientist in this and that's what gives me the confidence that I've actually started using it myself as well because sometimes again even though I've been a nutrition scientist for 25 years it's so confusing now to work out oh is this healthy for me? Isn't this healthy for me? Beyond the fact that yes, I know plant-based foods in their original format, nuts, seeds, et cetera, are going to be healthy.

51:59But when I'm trying to grab something on my way home, it's six o 'clock, I'm shattered. I've been working all day. I need to feed the kids. I want something quick and easy. I'm not going to start cooking from scratch. That's why I think it's really helpful for me because I'm going to go for a packaged pre-made meal in that situation is the unfortunate reality. I was thinking that one of the things that's been eye-opening for me over the last eight years at Zoe is realizing how different two foods might be that look the same. And before Zoe, I would never have turned a package over on the back and looked at the ingredients.

52:36And I just looked at it and be like, oh, that seems fine. I'm going to get one of those. So I think I am still sometimes a bit amazed that, for example, you could be looking at the bread in the supermarket and you could be walking along and there could be one bread with like a couple of ingredients and another one with 20 ingredients and they don't necessarily really look different, right? Yeah, totally. And I think what's important about the score that I've been working on is that it's not about the number of ingredients either. It's not about the number of additives because there's now some retailers that are bringing out these single ingredient foods as a way of trying to say, oh, this food is good for you because anything that's got loads of ingredients is obviously going to be bad for you.

53:17You could have some food that's got 20 ingredients in it, but they might be all of these wonderful nuts and seeds and bioactives. And so I think that's what I like is there's all of these tricks that are being used now to try and capitalize as well on people's fear of ultra-processed food. And that's what we've got to stop the fear of it. Is there anything in this presentation that I've missed as we've been chatting about it? So I do also like to talk about the good of the auto-processed food and some work that I've been involved with where we can actually harness food processing techniques to make the food even better.

53:57And we often call this health by stealth in nutrition. Health by stealth? Yes. There's a body of work that I've been involved with for many years which has been trying to generate a healthier bread. So we have created this bread that basically is a lot healthier for you than a typical bread, but tastes the same. And this is because we've been really clever with how we use food processing techniques. So what we've done is we've taken some chickpeas, we finely ground them, but we've ground them in such a way that the cellular structure is intact. So remember those cell walls, the cell walls or the water balloon?

54:34Yep. So you've got thousands of intact water balloons where they have not been burst yet. Amazing. And you put it into the bread. So firstly, you've got a chickpea flour that's slightly higher in protein than a typical wheat flour. You've got a flour where all the cell walls are intact, all the water balloons are intact. And when you put it into the bread and you feed these to participants, which is what we've done in our studies, you get about a 50 % lower post-meal glucose or blood sugar response. you get nearly 100 % difference in the feeling of fullness. So when you add it into the bread versus not having it in the bread, and remember I've said we've done all this sensory tasting, they taste the same, you have 100 % difference in how full you feel.

55:18You have more than 100 % difference in gut hormones. It's like this wonder bread, and that's because we've harnessed the power of processing to our benefit. And there's a whole other body of research that I've been involved with at King's, which is looking at how you can process wheat. you grind it in such a way that it releases the iron iron deficiency anemia is a huge problem in the uk in the us so many people about 30 of the population have insufficient iron stores it's really difficult to get iron from plant-based foods from wheat because generally it's within a really rigid structure within wheat what we call the allerone layer we've generated this kind of micro milling technique that basically releases the iron so that when you have the bread whether it's whole grain or white, you're actually getting that iron in a more accessible form.

56:07So that's two great examples of how processing can help us. Amazing. This explosion in obesity and diabetes and all these other lifestyle diseases, inflammation and negative impact on quality of life. People are actually dying younger now than a few years ago. To what extent is this linked to this rise in the high risk processed food that you're talking about today? So I think that the rise in obesity, the rise in chronic diseases that are underpinned by diet are due to lots of factors. They're due to the fact that we have a most evidentiary lifestyle. They're due to the fact we're not sleeping like we used to.

56:52They're due to the fact that we're more stressed than we were, but they're also a huge part due to the food that we're eating. Now, it's not just the fact that we're eating food that is processed with unhealthy additives and, you know, devoid of certain nutrients and has extra additional nutrients. I think that overall, the quality of the food has changed. But absolutely, yes, the way that the food is processed now compared to 100 years ago absolutely is responsible for some of this increase in obesity, some of this increase in chronic diseases. So if I just swap from like this high risk processed food to low risk processed food, do I significantly reduce my personal risks, both about health and also about sort of managing to keep control of my weight?

57:42I believe, based on the score that we've created, based on very strong science, if you swap from the high risk to even the medium risk, you'll reduce your risk. If you swap to the low risk, I believe you'll reduce it more. We're currently doing some quite intensive validation work within our cohorts where we can actually answer this question more clearly. And the initial analysis is really promising. But it's really important to reiterate that the processing score is just one aspect of the healthfulness of a food that we must also consider overall the healthfulness of the food, like the fibre, like the salt, like the sugar, for example, as well.

58:24But yes, I believe when you are thinking about what to feed your child that evening, what you want for your lunch that day, if you're looking at foods within a food group that are broadly similar, like sandwiches, for example, that might have broadly similar nutrient composition, that if you were to choose ones that are lower risk in terms of the processing versus higher risk, that absolutely over time, day after day, that will improve your overall health. The final question I have is coming back to this current explosion in the use of GLP-1s. Is it possible that this high risk processed food is part of what's causing the damage to our brains around hunger that these GLP-1 drugs then sort of fix?

59:13Yeah, so I think there's some evidence to show that they are overriding our fullness signals, partly through the speed at which you eat them, but partly through how they might interact or cause feedback to our fullness, our hunger centers in our brain. It's an emerging area of research. There's some evidence around food addiction. Some scientists say it's not a real thing. Some scientists say that actually if you see the dopamine response that goes on, particularly with these processed foods that have this kind of magic mixture of nutrients, it's causing this dopamine hit. It's overriding your natural fullness signals.

59:50I think it's emerging science. I think it would be wrong to say for sure, actually, yes, this process or this additive or this technique is definitely a problem and kind of mucking up our brain's natural way of thinking about food. But I think there's new research going on in this area at the moment. And so I think we'll have answers in the next five to 10 years. As you can imagine, hosting this podcast, running Zoe, juggling family life, it all keeps me pretty busy. So I try as best I can to stay energized and show up well in all those parts my life, by fueling my body with the right food, by exercising, and by adding a scoop of Daily 30 to my meals every day.

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1:01:12By the way, whenever we talk about Daily 30 as a good source of fiber, we're required to say that it contains four grams of total fat per serving. Obviously, that's all amazing healthy fats from plants. So order yours today at zoe.com slash daily 30. Thanks for listening and see you next time.