ZOE Science & Nutrition - LIVE Q&A: Your gut health, dementia and weight loss questions answered by Prof Tim Spector, Prof Sarah Berry & Dr Federica Amati

Episode Date: June 25, 2026

How quickly can you improve your gut health? Can diet help lower your risk of dementia? And what should you know about food labels and healthy weight loss? In this special live Q&A, Prof Tim Spector, Prof Sarah Berry and Dr Federica Amati answer your biggest nutrition questions and share practical, evidence-based advice you can use today. Drawing on decades of research and data from hundreds of thousands of people, they explain how diet can influence the gut microbiome, brain health, hunger, energy levels and long-term health. They discuss dementia risk, healthy snacking, intermittent fasting, ultra-processed foods, plant diversity, breakfast, food labels and the latest science on weight loss. You’ll learn how quickly the gut microbiome may respond to dietary change, why some foods keep you fuller for longer, how to build a healthier breakfast, and simple ways to make better food choices. The team also explain why small dietary changes can have lasting benefits. If your daily food choices influence your gut health, brain health and future wellbeing, which change is worth making first? 🌱 Try our science-backed and tasty wholefood supplement Daily30 🌿Let your gut microbes snack on the ZOE Gut Health Bar Get our brand-new app and Gut Health Test designed by world-leading gut health and nutrition scientists to build healthy eating habits 👉 Join ZOE Follow ZOE on Instagram. Timecodes 00:00 Intro 01:56 The first ever live ZOE podcast 09:14 How long does it really take to improve your gut microbiome? 12:56 Can you feel healthier before your gut microbiome changes? 14:15 Which foods should you always buy organic? 16:33 Are oats actually healthy? 18:36 The overnight oats trick that may improve blood sugar 19:28 Resistant starch: the hidden nutrient most people miss 21:32 Always hungry at 3pm? Sarah’s evidence-backed fix 27:17 The food industry trick that makes you eat more 29:44 Why ultra-processed foods leave you hungry 30:50 Does chewing more food really help you lose weight? 33:23 What does gut health have to do with depression and anxiety? 37:45 Is your gut controlling your brain? 39:34 Are fermented foods the most underrated brain-health food? 41:46 Starting Ozempic or Wegovy? Do this first 42:40 What do GLP-1 drugs do to your gut microbiome? 45:20 Tim Spector’s plan to fix Britain’s health crisis 47:55 Why governments still aren’t acting on ultra-processed foods 50:50 Have US food guidelines changed—and is the UK falling behind? 53:08 Is intermittent fasting safe for women? 56:15 What’s the healthiest breakfast to break a fast? 58:20 The science breakthroughs that could change nutrition forever 📚Books by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati The Appetite Reset by Dr Federica Amati Food For Life by Prof. Tim Spector Ferment by Prof. Tim Spector Good Mood Food (preorder) by Prof. Tim Spector Free resources from ZOE The Smart Snacking Guide: How to feed your gut, fuel your day, and snack without guilt The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra Eating for Better Brain Health: Your brain-gut blueprint How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks  Better Breakfast Guide Mentioned in today's episode Daily Sampling Reveals Personalized Diet-Microbiome Associations in Humans, Cell Host & Microbe (2019) ZOE’s PREDICT studies: What we’ve learned ZOE snacking study: What should you do? The Big IF Study: What did we find? Diet and Dementia, Neurology (2024) Daily30: Does it work? Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.

Welcome to Zoe Science and Nutrition, where world-leading scientists explain how their research can improve your health. The room hums with anticipation. Conversations fade. Stage lights glow against a packed audience as hundreds of people settle into their seats. Some have travelled for hours. Others have brought notebooks full of questions. All of them have come for the same reason to get answers.

For the first time ever, are Zoe's Science and Nutrition podcast left the studio behind for a live recording. We brought together a live audience of Zoe investors and gave them the opportunity to ask their biggest questions about food, health and the latest science directly to the experts that they know so well. Professor Tim Spector, Professor Sarah Berry and Dr Federica Amati all joined me on stage. And for the first time, this episode isn't shaped by a script, a producer or even a guest. it's shaped by the burning questions that people brought with them.

The questions range from the deeply practical to some of the biggest debates in nutrition. How quickly can changing your diet improve your gut microbiome? Does eating 30 plants a week really make a difference? Are oats healthy? Is snacking helping or harming us? What should you do after a course of antibiotics? And how should we think about weight loss drugs,

dementia prevention, and the many nutrition claims competing for our attention every day. I was terrified before doing this, but actually it ended up being a lot of fun, a conversation between experts and audience, spontaneous, insightful, and sometimes surprising. With no retakes and no shortage of curiosity, this special episode captures the excitement of a landmark first for the podcast, our very first live Q&A. Welcome everybody to what is a bit of a milestone for the podcast. This is the first time we have ever done. done a live podcast recording. This is also the first time we've ever had all three of our Zoe spokespeople together in one show. So we're about to discover whether or not we should have done

this ages ago or this is like a disaster and too many opinions all in one room. So I know you're all really excited about the audience Q&A and ready to go, but I thought before we could kick it off, I was going to ask each of you just one question. Starting with you, Tim, what does Zoe mean to you. Is this a yes or no? No, no. You're even allowed more than a sentence, Tim. Well, Zoe means life in Greek, and it certainly changed my life from when I first met you nine years ago now, and it changed me from, you know, a dull academic to a dull entrepreneur and scientists. But it's really allowed me to do what I was doing. on a very small scale, talking about gut microbe, but just talking to small rooms of academics,

small amounts of people, reading my work to re-bring those messages to hundreds of thousands and millions of people in a way that wouldn't have been possible before. And as it's grown and the company has evolved, we're seeing this as a very long-term mission. It's very hard at the beginning of it to see anything long-term because you say, are we going to say, are we going to survive a year, you know, will I strangle Jonathan after the first few meetings? Because when academics and business people clash, then often there's there are fireworks. But we got through that honeymoon period and we can now see this, this really important future. And I see, you know, this really important role for myself now, through, you know, the media stuff I'm doing and the

stuff we're doing for Zoe. It's all coming together. as a real mission to change the way we all think about food and the importance of food and give us extended healthy life and that all brings it back to the mission of Zoe. So it's really now very close to my heart and that's for me what Zoe means. It's bringing the science to so many more people that couldn't have had it before. That's really lovely. Sarah. I would say for me it's about putting science into action.

So I've been like Tim and academic scientists for over 25 years. I've run more than 30 randomized controlled trials. And yes, I'd spend years doing these studies, years applying for the funding, years recruiting people, years analyzing the samples, years writing it up, getting it into a manuscript. Did it make a difference? Well, I'm sure none of you have ever read any of those manuscripts. So I think what's really exciting is that we rarely as academics ever have the opportunity,

to communicate our research at the scale that we've been able to through the podcast, but also put into action research findings in the way that we do at Zeri from the own research that we do at Zeri in these hundreds of thousands of people at the scale, depth, breadth and precision that we could never, ever do in an academic setting. But also to be able to have all of the incredible resources that we have at Zeri that turn scientific information, scientific findings, into actionable advice that actually really makes a difference. And I've had the most exciting eight and a half years of my life.

It's just been so fun. I don't consider it work, my Zoe journey. I get up and I'm just so excited because the opportunities that we have is just so fun as a scientist. So I love all of that, but I am tempted to ask you to share your initial experience when we first tried to get you involved with Zoe.

Do you want the censored or unsensored version? I think they want the unsensored version. Okay, so I got an email from the esteemed professor, Tim Specter, who actually works in a different department for me. I'm in nutritional sciences. He was in genetic epidemiology. Even though he had already published world selling nutrition books, he was still just dabbling in nutrition,

because God forbid he's not in our department and dares to call himself a nutrition scientist. Sorry, Tim. She was one of the nicer ones. Yeah, so imagine what the others were like. That's quite true. Anyway, I had an email from Tim to ask me, would I come to talk to him about my muffins?

This is true. Everyone likes Sarah's muffins. So, what he did realize is that I had a lot more to offer than just my muffin recipe. And so he asked for me to come back and meet you and George, the other founder. And I remember meeting both of you and going back to one of my colleagues after saying, oh my God, I just met these two crazy guys. They think they can pull off a thousand people post-pranical study in nine months. Bearing of mind the kind of trials we did, we would have probably 20 people over three months doing this.

But you know what they say? There's a thin line between genius and madness. And what you did prove to me is that actually it's pure genius, no madness. and that Tim, you have learned to be a lot less rude, actually. And I do love working with you. And Federica, what does Zoe mean to you? So I think for me, I came from sort of the other side of it. So I was a public health scientist by training,

but I was a clinical nutritionist. So I was working one and one with people trying to really make an impact on their lives individually. And when I was introduced to Tim before I met Zoe, I was asked if I could help Tim with his Bible, also known as Food for Life, the first one, the big tone. And I was so excited to work on that because it was an opportunity to write a book that thousands of people would read

and it had so much information in it. And it was so applicable. And so when Tim said, I'm working on this project, it's called Zoe, I think you'd enjoy it, the potential impact that I thought I could help to bring to this company to Zoe in reaching millions of people with evidence-based advice that could change their lives at such scale just was so exciting to me. For me, Zoe's impact. That's what it represents. All right, we're going to move to audience Q&A here. So I've got a question here from

Faye Katstick. How quickly can I make beneficial changes to my gut microbiome by following Zoe's advice? And maybe I get Tim to start with this. There was a small study about 10 years ago that looked at a small number of people and sampled their stool sample every day and they were also looking at what they were eating every day and they were shifting their diets in certain directions and they could see changes on a daily basis in the gut microbiome. They were just looking at normal variation. They didn't try and just make it super healthy. So we have to extrapolate from that to our own studies where we've been doing projects where we clearly see changes within a month. And so it's somewhere between a few days and a month, depending on what you're looking at.

But I think generally it's really rapid in some microbes and in others it's going to take longer. I've got a second question from Sophie Pelker. How long does it take for your gut microbiome to change once you've introduced 30 different. types of plants a week. Well, again, we know that it depends where you start from. The worse your gut microbiome, the faster and the bigger the changes. If you're already at a really high point in your diet, you're having lots of fiber and ferments and everything else, it's going to be harder to see that difference.

These are really tough questions because all of you guys have really different gut microbiomes. You only share 20% with each other. So everyone's going to have a slightly personalized response to this. But in general, you'll see changes certainly within three months, even if you're at quite a high level, and probably six weeks. Would that then be the end of the change, or would you expect that to continue to change at three months, six months, 12 months?

I expect to keep going up, but everyone's going to have a different trajectory. And I think we do see this and people telling me their results. You know, they often see a sort of up and down trajectory, but generally creeping up, but you might have periods where it is a plateau and it is hard to get. And you've been on that journey yourself, Jonathan, with your fight against the antibiotics, where you've done all you can,

and there's a six-month period, and absolutely nothing's happened, and you feel a bit upset. But, you know, then six months later, it does start to climb again, and we don't totally understand why. that happens, maybe it's the seasons or other factors, or there's some other stress. You know, diet isn't the only thing affecting. I think what for me really is evidence for how, you know, increasing your plant diversity, getting to the 30 plants comes from our own randomized control trial that we did of daily 30.

And so we put our daily 30 to the test. We gave participants either daily 30 or two other controls. And then we looked after four weeks at how that changed the gut microbiome. and I was even surprised myself how people having two scoops of daily 30 a day had after four weeks profound changes in their gut microbiome. But I think what was even more exciting is how quickly you can feel different. So whilst you might not see changes in your microbiome for a week or two and these big changes after a month,

we know that people from changing their diet have improvements in mood, energy, hunger, alertness, even within two to three days. and I think that should always be a real motivator of how quickly changing your diet can improve how you feel now as long as your long-term, as well as your long-term health. Yes, your brain might be better at picking up the healthy gut than actually the microbiome test because we've got this high evolutionary system

that is really good at detecting what's going on. So listen to your energy levels and your mood. I've got a question here from Rachel Dixon. Is eating 30 different types of fruit and veg a week enough for good gut health, or does it need to be the right mix just for me? Also, is eating the same 30 types of plants each week bad, or is it okay? When we think of 30 plants a week, we want to introduce variety at every opportunity. So actually, rather not be the same 30 every week, try to change it with the seasons, try to experiment with new ingredients. 30 plants a week

is where the data has taken us so far. But There is a world in which 35, 40, 45 holds even more promise. Certainly that's what we see with fiber intake, that 30 grams a day is great. But when you get to 40, 50, 60, even 90 grams a day on one of our podcast guests, right, can still have benefits. So with plants, more is truly more. It's clear that it is one of the key ways to improve your gut health. As Tim said, there are other factors at play. But increasing your plant diversity is an amazing way to improve gut health overall.

All right, I've got another one here from Alan Murray. Bine or fruits and vegetables, organic, can be expensive. Which fruits and vegetables are most likely to have a high pesticide residue and are worth the extra cost for organic? And on the other hand, are there ones which usually have low pesticide residue? Pesticides and herbicides, I think we use those terms interchangeably, but a lot of it is herbicides to stop weeds growing rather than bugs. and the main one is glyphosate is used extensively on wet crops like oats and rye,

used both to stop weeds growing, but it's also then used to dry the crops out. And so I would say, you know, oat products have the highest levels of these pesticides. So that's the first thing you should always try and get organically because excessive levels in some of these breakfast cereals if they're not organic. Berries are particularly prone to problems and they also rot, and so they get sprayed a lot with chemicals. Strawberries in particular always seem to come up in the high lists in both the US and the UK, and most other berries as well.

Now, I know you shouldn't always put things like raspberries and things under the tap because it rather ruins them. But there's always that weighing up the pros and cons of doing that. And there's many fruits and veg you don't have to worry about. Those with thick skin, oranges, you don't have to worry about, avocados, you don't have to worry about, anything of the really thick skin should be fine. Things with thin skin, the chemicals can get inside.

And if you just have it occasionally, I wouldn't worry at all. But if it's part of your regular diet, then do make an extra effort to pay the extra money to get it organic. That would be my view. I think it's also worth remembering most of us aren't eating enough plants full stop. So get your amounts of plants up first. Organic frozen berries are actually much more affordable than organic fresh berries and obviously last longer. So that's a good tip. And pick the ones that you can afford organic, but remember the benefits of eating them, whether organic or not, is better than not eating them. Oh, there's one about oats. So that's a fantastic transition from Daniel Bellion here.

I see a lot of debate about oats in the morning. Is it a healthy solution? Let's say three times a week. And I think we definitely need to go to Sarah on this one. Well, we have an entire podcast on this. So go check that out. Absolutely. I think oats are a fantastic option. I would caveat that, though, saying the most unprocessed oats, so you're still-cut oats that take longer to cook are the best oats to have. The ones that you get in these sachets that have all sorts of additives, emulsifiers, sugars, fecal, goodness knows what added. No, I wouldn't consider them healthy. You know, it's just kind of the old-fashioned traditional oats. Look at the back of pack labeling. It will just say oats. And the reason that they're good for you is because they have lots of

nutrients, lots of micronutrients. They're very high in different micronutrients. They're also one of the few that are also high, cereals are also relatively high in protein, but they're also high in a particular fibre called beta-glucan. And beta-glucan, we know once you get to a certain dose, which you can if you're having porridge regularly, can significantly reduce your cholesterol levels, but particularly reduce your LDL cholesterol, which is your bad cholesterol. So I would consider them a hot healthy breakfast as well as healthy because of the other micronutrients fiber that's in them. Now, I would say I'm someone who doesn't have very good blood sugar control and I've worn one of these continuous glucose monitors quite a few times eating oats,

including on that podcast, Sarah. And my experience is I've yet to find oats that are cooked over the hob that don't spike me. But I know Federica, you told me that there is a tip for people who are like, you know, would maybe like to have oats, but for whom honestly you know, even the ones you're, you know, pretty much everything that you buy standard that you can find in the supermarket still leading to this really big spike and collapse. Federica, what did you tell me?

Soaking your oats overnight is a really fantastic way to have them. It doesn't make the starches more readily available in the same way cooking does. It also increases the availability of some of the micronutrients that Sarah described. And so overnight oats is a really fantastic way to consume oats. And it means your breakfast is ready in the morning and you'd have to think about it,

which is really good. I think as well, Jonathan, we can consider it as a foundation of the breakfast rather than the standalone breakfast. If you can add in other sources of healthy fats and healthy protein, you're going to balance out your blood sugar, even if you typically get a spike from it. It'll keep you full of for longer. You won't be on that roller coaster. So add nut butters to it or add nuts, seeds, you know, these kind of toppings. And then you're really kind of boosting a foundation that's very good with added plants and diversity as well. Federico, you just mentioned resistant starch, which conjures up this image of like the starch that's really unwilling to be where it is. What does it mean? So resistant starch is a type of

pseudo-fiber, it's a type of fiber that basically reaches the furthest part of your colon. It's a slower fermentable fiber and our guts are starving for this type of fiber. They're also in things like green bananas and other whole grains. And they're especially good to feed our gut microbiome. And the gut microbes that produce these helpful metabolites called short-chain fatty acids. And these are incredibly important for ascertainty signaling. So Sarah just mentioned, porridge is one of these foods that helps to keep you full for quite a long time, especially when it's cooked well, balanced well. And one of the reasons is because the resistant starch fermentation resulting in short-chain

fatty acid production stimulates the nutrient-sensing cells in our gut that release hormones like GLP1 and PYY. And that happens quite a few hours after you eat because it's in the distal part of your colon. So it's a real good way to help you feeling satiated for longer and to feed your gut microbes what they love. A tip to get extra resistant starch is, you know, after you've made your potatoes or your, as Federica prefers, pasta, you put it in the fridge overnight, reheat it, and it's got about 40% more resistant starch in it. So actually it will have more fiber the next day and it'll fill you up more and it's more nutritious. So it's really weird that, you know, leftovers can be healthier than the fresh.

So does that mean that you get less of the blood sugar spike as a result of turning it from like the normal? From sugar to fiber, essentially. That's what it's doing. It's transforming the starch into a form that can't be digested in the early part of the colon and it can only be digested by the microbes further on. So always make more pasta and stick it in the fridge. Tim's tip is absolutely right. Cooling your starches increases resistant starch. All right, this is definitely one for you, Sarah.

I have a question here from Jen. I find it really hard to not snack in the afternoon. What can I do to get me through to dinner time, which pretty much describes me every day. What can you tell us, Sarah? Snacking itself is not bad for you. It's about what you snack on. We know in the UK, in the US, in many countries,

we get between 20 to 25%, so a quarter of our calories from snacks, that's huge. And I think rather than demonising snacking, we should be embracing it if we are a snacker as a really simple, single dietary strategy to improve our help. I've run a randomised control trial where the only thing I changed in individuals was their snacks. I said, keep everything else the same. After just six weeks, people improved their blood lipids, so their cholesterol, their blood vessel function to such an extent it equated to a 30% reduction in cardiovascular disease risk just from changing their snacks. And that shows the power of snacking. The problem is, is in the UK, many of us

snack on the wrong foods. We know again from our own Zoro-Predict research that about 40% of people that put in loads of effort over their main meals undo it all by eating really poor quality snacks. And we do have a problem that there aren't enough pre-packaged snacks out there. But But something I'm incredibly excited about is that we at Zoe will be launching our own snack bar that we have all created. That is, I think, the answer to snacking in the UK. And what's really exciting is we've really taken a different approach to snacking. Why no one else has done this before, I do not know.

It's a snack bar that's packed full of healthy protein. It's quite high in healthy protein. is packed full of fibre. It's got a whopping 8 grams of fibre. So if you're snacking two times a day, having two bars a day, which is what's typical in the UK, two snacks a day,

you're going to be getting nearly 20 grams of fibre. And it's a diversity fibre because each bar has 12 to 13 different types of plants. The other thing that's really exciting about this snack bar is that we've created it to make sure that the matrix of the structure of the plants that are in it are intact. And we know that's important,

because we know it impacts how quickly you digest it, where you digest it, and what's left over for your gut microbes to absorb. And then lastly, the icing on the cake is we've made the texture be quite chewy. So it's hard to guzzle it down. You know, we live in this broken food landscape where so much of the food is soft texture, so you eat it so, so fast.

And you'll have eaten two snack bars before you've even registered that something's got to your tummy. And so intentionally, we've produced a bar, that is hard in texture, that you slow down how much you eat. And we know, again, from our own Zoe, predict research, that this means that you have better metabolic health. You consume less calories later in the day. So it's just the perfect, perfect food, snack.

Bar. I'd like to let you into a little secret. I'm a big snacker. Most days, I eat a big healthy breakfast and lunch, and I still crave a snack, especially mid-afternoon. If I'm at home, I can usually find something I feel good about eating. But when I'm out and about, this is usually impossible. And honestly, sometimes I just don't want to eat yet another bag of nuts.

So I end up in a shop looking at a huge variety of snack bars. And they all seem great until I turn them over to look at the food label. And then I get really frustrated. There's this long list of unrecognizable ingredients, plus a ton of added sugar. If I'm feeling a strong-willed, I resist. But let's be honest, I'm hungry and I'm tired, so often I eat it anyway. But once my hunger has subsided, it leaves me feeling furious with the big food companies that sell these products, with all their fake health claims and offering nothing that's actually good for me.

I complained about this to the team at Zoe frequently. So imagine my surprise when our chief scientist, Sarah Berry, said she thought we could solve this and create a snack bar that was actually good for my gut health. There have to be some benefits to being a CEO, So rather selfishly, I said, yes, as long as you can do a dark chocolate flavor. And today, I have some incredibly exciting news. We've created the Zoe Gut Health Bar, a snack that's designed to taste great and support your gut health. The gut health bar is filled with plants, carefully selected by Sarah and our team of gut health scientists.

It's delicious and satisfying to eat, and it contains a huge diversity of plants with their cell walls preserved, which we talk about so often on this podcast, and is designed to feed your gut microbes. It's got 7 grams of plant protein, a huge 8 grams of fiber, and 12 to 13 plants in each bar, depending on the flavour. My favourite is a 70% dark chocolate bar, but my co-founder Tim Spector prefers the raspberry and goji berry flavor. Perhaps I'm biased, but I think our gut health bar is delicious, and I love the fact that it takes time to chew, instead of being hyper palatable and stuff full of artificial additives.

Ever since I got the first samples, I never leave the house without a couple of these in my bag. I can't wait for you to try them for yourself, and let me know what you think. Head to zoe.com slash snack bar and try it for yourself. That's zoe.com slash snack bar. Your gut will thank you. A lot of food that we eat is designed to be predigested or pre-chewed.

Maybe Tim, could you talk from a minute about? like why is that? Yeah, it's the way the food industry has been designing food, you know, since about the late 1960s, 70s has been slowly building up this portfolio of foods, and they've realized that it's much easier to work with foods if you strip them of the outside shell of the plant. So you get rid of the kernel, the fiberous bits that contain nutrition, because they're hard to manipulate, and they also make. it more like it's going to go off. So that's the reason white rice is there because white rice doesn't go off, whereas brown rice will go rotten if left in a mill. So that's where our ancestors

worked out. Same with flour. And brown flour and white flour, you clean it out of all the other stuff, and then it will last much longer. And also, they're able to manipulate all these plants, just taking the inside bits of it out, getting rid of anything hard. And so they can heat it up, pressurize it, they can, you know, make it look like a potato in a Pringles or a Dorito, you know, even if it's made of rice. And they also realize that some people just like eating baby food all their life. You know, we're evolutionary ideas that, you know, it goes from mother's milk, and there's a little bit of weaning and a bit of squash banana, and some people stay in that state for 60 years. Many people aren't chewing at all, anything. And, you know,

that's why you go to fast food places and those burgers, buns are incredibly soft. You know, you don't really need teeth to eat them. And we're in this state. So it's partly that they've adapted to this very sort of infantile way of eating, but also it's incredibly cost effective for these industries to make foods like this. And they also know that the softer it is, the faster you can eat it, the more you overcome your normal fullness. you'll keep eating much more of it and they'll sell more of this stuff and they don't mind you just

get fat. You know, that's all good for business. So the pre-chude basically means you're just going to sort of wolf it down. You won't even realize you're full and you're sort of onto the second bar before your brain has even realized the first one is. You know, the big bag of potato chips or whatever is and you just don't even notice you're eating it. I think critically, by stripping out the fibers that Tim's talking about, we aren't activating these satiety signals as well. So you're you're eating quite a lot of energy. These are energy-dense foods, quite a lot of calories in them. You might get a little bit of satiety from the stretch receptors in your stomach.

They sense something is there. But because it's smushy, it's absorbed so quickly in the small intestine so high up, that then there's nothing happening after that to say that there's still food going through and it's nutritious. So by making it so nutrient-lacking and low in fibre, you can eat quite quickly, eat a lot of it, but actually still feel hungry half an hour later, this is excellent for profit.

Because to Tim's point, we have this enormous amount of food available in terms of calories per person, it's about 4,000 calories a day per person available in the food system. But they're not satiating calories. So it means that we're buying more and they're able to market more products, and we still continue to eat more and more.

But it's not helping us in terms of satiety or nutritional status or fibre. I think Sarah did have studied about chewing. the lovely spit studies. Yeah. Oh, my chewing spit studies. Yeah, so we've done studies where we've looked at feeding people identical foods, where you just change the structure of the food,

so you just change the texture in the way that Tim's talking about how the food industry change the texture, but where you'll give people, for example, large porridge versus finely ground porridge. Back-upack labelling's the same, nutrients are the same. All you've done is change both the texture and the structure of the food. it changes obviously how much you chew it but it changes actually how your body metabolises and processes it it changes to Federica's point where you absorb it

the larger more intact plants are absorbed lower down your gastrointestinal tract that are packed full of these gLP1 fullness receptors when the food industry are finally grinding breaking up everything softer texture is all absorbed higher up you don't therefore like federica said get that kind of fullness we also know that how much you chew your food also determines how full you feel as well and if the food is already mush you're not chewing it

both you and federica got very excited about the idea that the bar was something you had to chew is this why that was such a big deal for you both yeah so by chewing it that itself will feed back some sort of satiety fullness signal but more importantly we'll slow down how fast you eat the food by having that harder texture. And that's really important because we know if you look at two foods, one that could be minimally processed and one that is processed, even if they're similar foods,

you get about a 50% difference in the rate at which you eat it. That results in at least a 50% difference in how full you feel from the food, but also a difference in how many calories you go on to consume after. There's a wonderful phrase that one of my colleagues who works in food texture, his entire career is about few texture that he often says, which is very practical based, put the crunch back into your lunch.

It's a simple strategy, and there's studies to show you could have a soft burger, soft patty, soft bun, soft lettuce, or you could just crisp it all up. Just by putting the crisp, the crunch back into it

means you're chewing it more, means you're slowing down, and what the study shows you'll consume less of that food and you'll have a better metabolic response. Is this what you like, like crisp sandwiches. I love my crisp sandwiches.

All right, I'm going to move us on before there's any fighting in that corner of the couch. So we are going to talk about brain health and mental health because we've had lots of questions around this. And I know that, Tim, this is something that you've been very excited about over the last year and we have some exciting upcoming books. So let me start with the first question from Andrea Frida's. What evidence supports the link between gut health and mental health. And how strong is the current research on this? I think it's a really serious topic

because every person with a brain disorder, I prefer to call them brain disorders, then separate mental health from degenerative brain health. It's all the same organ. And really, there isn't really separation between mind and body. It's just another organ that's going wrong. In every condition studied, there's an abnormality. There's an abnormality. in the gut microbiome when you compare cases with the disease and controls without it. So everything that goes from dementia, Alzheimer's, Parkinson's disease, all the way through to autism, to schizophrenia, to depression, anxiety, PTSD, obsessional disorders, everything. Something's going on in the gut microbiome. Now that's association. It doesn't necessarily mean

it's causation. And it's quite hard to do this. because you'd have to test someone and then wait 10 years in a cohort to do that, and the field is too young. So we have to rely on mouse studies to really show us what's going on. I don't do mouse experiments, but I have to read about them. And these mouse studies are really good at showing mechanisms are possible. Obviously, humans are not mice, but really clever experiments have taken transplants from one mouse to another, you take an anxious mouse, you take their poo, you transplant it into a germ-free, sterile mouse,

you can make that mouse anxious. And by using antibiotics and things, you can reverse that process. There are also some experiments where they've put stool samples from humans with depression or anxiety, and they've transplanted sterile mice with them, and they've reproduced those symptoms. And they've also done that for other mental health disorders like psychosis. and schizophrenia. So there really is pretty good evidence that there is a link between the two.

There are also really interesting links in brain diseases like Parkinson's, which is a shaking palsy, but it's associated with dementia, and that's really increasing at the moment. And when they look back at their history, they find that 10 years before, the majority of people who developed these brain symptoms had really bad constipation and gut problems.

And they're finding that the gut microbiome in those people was abnormal 10 years before and had proteins that were being formed because there was inflammation in the gut microbiome. And we think the link is not the microbes themselves, but it's actually this whole concept of inflammation. because microbes are controlling our immune system, something goes wrong, the immune system goes out of control, you get extra inflammation, and that's why this applies to all brain diseases, not just one or two.

This is very much a holistic problem, and that's why we're facing this epidemic in this country. For you, it's really clear. The links between gut health and brain health are really strong, and there's a lot of increasing data that shows that from, you know, experiments with mice on one end, but these examples you're talking about people developing constipation and gut problems, like 10 years before they develop a brain disease. And the second thing I heard you say, which is really striking, is that this divide between

mental health problems like depression and anxiety, and what I guess I would have thought of as brain health problems like dementia, for you isn't really real. These are all just one group of things that are going wrong with your brain. And the inflammation for you is maybe this key explanation for the link between like the food and your gut health and what is happening in your brain. Yeah, that's right. You know, psychiatrists have divided the brain disorders into 360 different conditions and all of them have no diagnostic test. They're just a group of symptoms that every, you know, five or ten years, psychiatrists agree this goes together with this. But they all overlap. They all have the same risk factors. They,

all end up having multiple symptoms overlapping by, you know, after a period of 20 years. And the genes, I used to be big into genetics, the genes from risk of these are all the same. There's no big difference. It looks like it's just one disease that's just presenting differently at different times in life, maybe, you know, at different exposures. So I think we need to step back and take a much more holistic view of mental health and realize that the one thing we've been overlooking and psychiatrists have never really talk about is how important the gut is and how important our diet is.

And why we've got the biggest nerve in our body runs from our gut to our brain and 80% of the traffic is from the intestine to the brain, not the other way around. Whereas the rest of the body, the nerves all run most of the signals from the brain to the rest of the body, whereas the gut is the opposite. The gut could be, seem to be, directing the brain. So I think once you sort of change this paradigm, we can start to really get to grips with it. And people see the link between mood and food.

And that's what we saw in these trials. In all the Zoe studies we do, whether it's of daily 30, of the method study, fermented foods, first thing that changes is the brain symptoms. I've got a question here from Dr. Saz Gus Scott. the fermented foods data on inflammation is striking. Given how tightly we now link inflammation to depression, do you think that fermented foods are one of the more underrated mental health interventions?

Would either of you like to take that? Well, short answer is yes. Fremented foods probably work in a different method by different mechanisms. So they're acting synergistically together. So just because you're having fermented foods alone, you know, will help particularly, inflammation, but we don't know, but it's highly likely that adding 30 plants on top of that is also going to help, and no one's yet done that study.

Amanda Howell says, my family doesn't believe me when I suggest that nutrition and lifestyle changes can significantly impact their future risk of dementia. Am I right? And what would you say to convince them in no more than two sentences? Tough one, Tim. there's a whole wealth of information. There isn't one blockbuster study that does it, but there's clear data showing that all things associated with poor diet are associated with increased risk of dementia.

We know that mouse brains don't develop without a healthy gut microbiome. So we know there's a link between the brain function and this. We know that bad foods are associated with it, and there's unlimited observational epidemiology studies making this link. There's also one of the biggest risk factors for dementia is type 2 diabetes. The main risk factor for type 2 diabetes is poor diet and poor gut microbiome. So, you know, I would just say, ask any epidemiologist, and so they'll say there's overwhelming evidence. 80% of dementia is preventable with lifestyle and nutrition intervention.

80%. Amanda, hopefully that's good enough for your family. Good luck. We covered a lot of ground in this episode. If you have a friend

who isn't an expert on nutrition but is showing signs that they'd like to make some changes to improve their health, then this episode could be the perfect introduction. The chances are one person in the room

at our live Q&A asks the exact question that they're struggling with. From what to do after taking antibiotics to advice for the family member who's starting GLP1 drugs, send them this episode and help them on their journey. All right, I'd like to switch topic here.

We had a number of questions here about weight loss drugs from Dominic H. What would your number one piece of advice to people starting out on weight loss drugs be? And I think that's definitely for you, Federica. Great question. My number one piece of advice would be to actually start the dietary change before you start the drugs. the most common side effects of these drugs are gastrointestinal side effects, diarrhea, nausea, constipation, reflux. If you set your gut up for success before you start these drugs, the likelihood of suffering these side effects is lower, and the likelihood that you'll have

efficacy at a lower dose is higher. So prepare before you start, and then during treatment, nutrient density, every bite of food counts. And I've got a follow-up question also about GLP-1s from Claire Lane. What effect do GLP-1 agonists have on the gut microbiome? Does it make it less diverse as people taking them are tending to eat less well whilst taking them? We don't have loads of data on this. It'd be good to have more, but the data we do have shows that there are gut microbiome changes

with GLP-1 medication. They're associated with the slowing of the gut transit. So gut motility slows right down. and that in itself changes the environment that gut microbes are reproducing and living in. Diet absolutely changes as well. So depending on how your diet changes in this time, you can either see an improvement in the gut microbiome

or if you're just eating bad food but less of it, then obviously we see negative changes. These drugs absolutely interact with the gut microbiome. We're just starting to understand how we can preserve gut microbiome health, gut health, but also how the actions of the gut microbes you have can actually amplify and better the effects of the drug. And that's, I think, where the really exciting science is coming out on that,

how we can help our gut microbiome make these drugs more effective and more tolerable. Is it possible to use these GLP-1 drugs and actually improve your diet, or actually is that sort of an illusion? These drugs offer an opportunity to improve your diet in a way that will improve your gut microbiome composition, improve your health. If you are able to prepare for the drugs and improve your diet significantly during treatment, the long-term effects and the beneficial effects on your gut microbiome are real. But if you don't do anything, if you just take the drugs and think this is a silver bullet, then the likelihood is it will go the opposite way and you'll be squandering an opportunity to improve your health. I'd go even further. I'd say it's a real disgrace that the government who is saying they're trying to roll this out to people are spending taxpayers' money on this really expensive drug without giving people clear mechanisms to change their food behavior. This is an incredible opportunity that the NHS is squandering. So that's where most people will take the drug, they'll lose weight, they'll stop taking the drug,

They'll put the weight back on. They'll go back to their old ways. And it really is a national disgrace if we can't use this long-term and we need tools like the Zoe app, which cost a trivial fraction of the cost of a drug to be given in conjunction with them. I've got a question here from Becky Tucker. Tim, if you were given responsibility

for improving the country's health over the next 10 years, what are the three biggest changes you would make to the food environment rather than to individuals' behaviour? Great question, and there's a reason I'm not a politician. The first one would be to have strict rules about what food should be served in government-run institutions. Something's very easy to do.

You just say in schools, in universities, in public places, hospitals, that we don't want any of the, you know, medium and high-risk ultra-processed foods. That would be number one. Very easy to do. We've got the, you know, got our new Zoe classification, makes it really clear. That would cut out 25% of the foods that are causing the most damage to our population. I would ban at the same time, you know, vending machines and things like this

that are also making our health staff really unhealthy. My second one would be to pass a rule saying that any clearly unhealthy ultra-processed food is not allowed to have health claims on the packet to fool consumers, particularly parents of children that are being targeted with these high in protein, low calorie, low fat, high in vitamins, all this nonsense for really unhealthy rubbish. And Tim, is that a big issue? It's a huge issue. most people are completely fooled when they go into supermarkets about what to buy.

And they're trying to do the best for their family. They think they're doing it because they see nice pretty pictures or cartoons or people of happy, you know, farmers getting these products. And it's all a lie. And other countries have taken these steps. So there will be the first two things I would do. well third would be to teach about food and health at school and we've dropped that now it should be taught as a primary subject just like reading and writing everyone needs to know how to cook a few simple

meals and understand food if you don't understand it it's going to be a meal loss for the rest of your life and many people are not being told how to cook only to microwave I've got to question here from Michael Burnham. The team's visibility across the media is impressive. The message around the negative impact on UPF is cutting through. However, there seems to be very little evidence that the UK government is moving to address this issue. What else can be done? And I think it'd be interesting also to talk about the situation, not just here in the UK, but more broadly. Let's start with Sarah. I think that absolutely enough is not being done. do believe that there are efforts that are being made to use processing in a way that can improve

health rather than damage health, but I think it's too little too late in the journey. And I think we're in disastrous times when it comes to the food that we have because it's not just about what's on our shelves. It's about what we have become accustomed to. So we have become accustomed to cooking foods that take two minutes in a microwave. And, you know, this feeds into what Tim said is his third point. We're bringing up children that aren't educated to be able to cook. And I think that it's not just about, therefore, you know, putting taxes on all UPF foods. We have to think of the bigger picture. And there is a big problem as well, Jonathan, that ultra-processed foods are 50% cheaper than an equivalent minimally processed food. And so there's a very

difficult task that the government has that we don't widen disparities. And so because of that we're stalling. And I think the other thing that's a big problem is in the scientific community as well, there's a lot of discourse around ultraprose food. What is it about it that's bad for us? And because of that, again, we're stalling. We're never going to know exactly what additive emulsifier cocktail mix is bad for us. We need to embrace the fact that there is too much heavily processed unhealthy food and we need to act fast, but there's too many excuses happening. internationally it's important to recognize that at least 12 and probably maybe double that number of countries have now produced national guidelines to say that ultra-processed food however they define it is unhealthy and should be avoided and the UK is not one of them and the UK has resisted this through its nutrition committee which sits supposedly independent and says there is just isn't enough evidence to say that ultra-processed food is bad for us, but all these other countries disagree and are moving forward with legislation to do it.

It's worse than that. The government recently announced that they might lower the price of biscuits and other ultra-processed foods to help families. I think we need to really think about subsidising healthy food and making whole foods much cheaper than these ultra-processed foods so that they become the obvious choice. That's what got to be one of the levers that we have to look at. Great transition to my next question, which is from Karen Boyd. The American food guidelines have changed recently, so the pyramid is now the other way up. Will the UK follow suit? United States Department of Agriculture have these guidelines that they change every 10 years.

And most countries follow their guidelines because they're thought to be the ones that so lead the world in this. And 10 years ago, they're actually quite similar to the current UK guidelines. and that they mainly demonise fats, you know, they're sort of favouring starchy foods. They do say don't have lots of sugary drinks. They say eat more fruits and vegetables, have a bit of fish, and they were sort of bit on the fence on protein and whatever. They didn't mention ultra-processed food at all, didn't mention gut health at all. Now, the new guidelines, they mention,

fermented foods being good. They mention that the microbiome is really important for the first time ever. They mentioned that ultra-processed foods are bad and shouldn't be given to children including

any sugary drinks under the age of four or even artificial sweeteners under the age of four, which is something the UK says is fine. And where they went a bit weird is they then said, but you should have even more meat and butter.

Already the average American has twice as much meat as the average European, and they're saying, no, that's not enough. You need to have these protein levels that are right up here, but you've also got to do this other stuff and have a ton of vegetables. Do you think they should be eating more red meat? No. They don't need to be twice as much as the Europeans, let alone four times as much.

At that level, particularly when most of it is, processed and poor quality, it's going to increase the cancer rates, it's going to increase heart disease rates. And the more meat you've got on the plate, how can you squeeze your 30 plants? It's very hard. There's no room. It's basically those big American steaks. By the time you finish that, even your salad seems very hard work.

Actually, I think there's a great transition to the next question from Sonia Castro, because it's about intermittent fasting, which is definitely new science. is intermittent fasting suitable for women, especially those who are post-menopausal? This question comes up a lot because I think on social media, women are singled out and said, this is highly dangerous,

and it's not safe for women, it's only safe for men, and there's big disparity. When you look at the studies that have been done, they're virtually all in men, and they're virtually all in young men. One exception to that is the Zoe, Big If study, 150,000 or so people did, and I think 65, 70% were women.

So it's the largest group of women doing intermittent fasting. And we found that actually, you know, two-thirds of people, regardless of being May or female, really benefited from it. They got better mood, better energy. they had less bloating and they enjoyed. A third didn't. It is personalised, but there's absolutely no evidence that's harmful as long as it's not extreme.

And I think what we're talking about is really quite modest ones of 12 to 14 hours without eating, which is not the same as going three days without eating. I would say it really depends. A lot of women who do try intermittent fasting sometimes take it to the extremes, as Tim said, and actually what we do know is that because women are often subjected to diet culture, a further way to restrict your diet is probably not going to help you. And overnight fast makes sense physiologically, so just not eating at night time is a good idea. But don't make this into another rule where it leads to further restriction,

because I think that's where harm can happen. Or anxiety or stress or mental, you know, angst. Can I actually add something to this, you know, given that as though we have run one of the world's largest studies, in peri and postmenopausal women. And what we know is that peri and postmenopausal women metabolize their food differently. We know that they have different perceptions of hunger. And so I think from a very practical point of view, in terms of the question that's been asked around intermittent fasting,

is that actually it's not so much probably the duration of the fast that matters here. It's about the timing of the fast. What we know is that if you consume calories later in the evening, you wake up more hungry the next day, you have worse metabolic responses the next day. And given that our own research shows that postmenopausal women already have more exaggerated responses, already are more hungry or ready more prone to put weight on in the wrong places, maybe focus not so much on thinking, oh my God, have I eaten in a 10-hour window?

But think about focusing on, okay, let's try and not eat off to 8 o'clock tonight or 10 o'clock tonight. All right. I think we've got time for one final question from the audience. And Sarah Rodriguez asked, in a perfect world, what is the best food to eat to break your fast? So I'd like to use myself as an example. Before I started my journey with Zoe, despite being a nutrition scientist for 20 years by then, I did start my breakfast with pan of chocolates, croissons. And boy, I'd be hungry and hungry a few hours later.

and then having met Tim and heard all about his breakfast and gave it a go. And I tell you what, I feel full for four hours, which for me is perfect, but the quality of the foods I'm getting are fantastic. And most of you will probably, if you followed Tim, will know what his breakfast is. So it's a mix of khefis. You've got all those wonderful happy bugs dancing around in your bowl. Greek yogurt. So you've got a whacking amount of healthy protein as well.

and then whatever mixture of nuts, seeds, berries, etc, you want to put in, I add a bit of nut butter as well. It keeps me full. I'm getting plant diversity. Obviously, I add my daily 30 scoop on top as well. It's nice to have like a favourite breakfast, but I actually change it. So in the winter, I love a porridge. But in the summer, I absolutely love overnight oats, avocado on toast.

I love crispy eggs, extra veg and olive oil, make it hot, then crisp them. Delicious. They're so good. my girls love them too. So it's nice to change your breakfast up, but what Sarah's described there is a really good combination of healthy fats, healthy proteins, a variety of fibres and plants, flavor and enough food to keep you satiated. Because we actually also know from our own research that having a really satiating and nutritious meal, whenever you break a fast, if you're Tim, it might be 1112, if your meat or Sarah might be earlier in the day, it helps you to sustain energy levels

and have better nutritional choices later in the day. So begin with breakfast is one of our principles because if you have a very good breakfast, it actually does set you up well for the rest of the day. We don't have time for any more Q&A from the audience, but just to wrap up, I'd like to get one quick answer from each of you, if that's all right, about what you're most excited about for the next 12 months.

And we had a number of questions from our audience around this. and maybe let me start with you, Federica. Okay. So I'm really excited about what we're learning of how we can better understand the messages that happen within our bodies. So whether these are the appetite regulating hormones that are so popular now,

but also what Tim described, how the vagus nerve communicates with our brain. So there's some really exciting science emerging on how things like vagus nerve stimulation and mitigating our stress can actually impact our nutrition. health because our body is one and how stressed we are, how well we modify these things actually affects how we absorb nutrients from our food. So I'm really excited about that from a science

point of view, as well as really excited to see how the gut microbiome science that we've been able to contribute to is helping to shape the future of medicine, whether it's through colorectal cancer, early colorectal cancer research that Sarah's involved in, and some of the type two diabetes research that we've been able to unpick. So those two for me, as a scientist and as a clinician, I'm like, this is so exciting. Sarah? I am most excited about the gut health bar coming out and about the fact that we,

staying true to Zeri values, are going to put it to the test. And so my science team, our science team, are going to be running a randomized control trial, which will be publicly available for everyone to see the results.

So we're taking a big chance, but actually I don't believe we are. My hypothesis is that we will see people consuming our gut health bar versus a standard breakfast bar, we will see significant improvements in how people feel their gut health, their microbiome, etc. And I'm willing to bet something on it.

You name it or better. Dinner on you, Sarah. Dinner on me. If we don't see these improvements, and this is how confident I am, I will take you all out for dinner. Wow. Not to McDonald's, though.

But what time carriages are coming. Last but not least, Tim. Well, it's probably not a big surprise. I think the next year is going to be the year of the brain and how we can tell more and more people about the gut-brain connection, how people outside this room who aren't aficionados can start to see the links themselves between the terrible food environment

and their poor mental health and the rise in dementia. And, you know, I think all our studies are now really gearing up to be looking at these factors much more. Every time we do a Zoe study, we're going to be looking at mood and energy and all these brain things first. I'm told these in the app like we used to in the COVID studies when people are looking at their mood so people can track their mental health, just like they track their blood pressure and everything else.

And I think people will see these changes, and hopefully this will lead to a real revolution in how we see food. This is the real antidote to the epidemic of brain diseases that we're having at the moment. And we can start to spread the word. And the microbiome stuff hopefully will also give us clues because we've now got this database of over a third of a million people, of which a fifth have got some depression. We can actually highlight microbes that we can target in the future with prebartics and probiotics.

So, yeah, I'm super excited that, you know, we can tackle the hardest problem of all, which is, you know, getting our brains healthier, and we all need them. Jonathan, you're always the host, so you never get asked the questions. But I think it would be great to hear from you your Zoe journey or what you're most excited about the next 12 months. Oh, that was mean. I wasn't expecting that.

I actually think it came up in one of the audience questions. I think the thing that I'm most excited about is that we are, finally starting to have an impact on the conversation about the central role of gut health. And on the other hand, how we're really fighting this ultra-process food and that it is just so bad for us. And when I first got involved in Zoe, you know, we were talking about personalising advice. We're definitely talking about gut health. We didn't talk about the ultra-process food at all. And I think I was very excited by the ability to use all of this data, a very large scale. That was my background to give this personalized advice.

And over time, I think, and I think Tim has felt the same way. I've just got angrier and angrier as I understand the reality of the food that's around us and just how terrible it is. And you can't even know, right? It has these labels that tell you this stuff is great for you. It's high in protein. It's good for your family. And then you realize, like, I've been feeding my children terrible stuff. I've been feeding myself terrible stuff.

I optimistically believe that we are starting to change that conversation. So I am really hopeful that in a year, we will have more positive things to say about how actually industry is being forced to make changes because of the demands from not just people in this room, but people are listening to their podcast, people involved with Zoe all over the world, and that that actually can have this really amazing impact on people's health. So I think that is what I am most optimistically hoping for in an environment

where there seems like loads of terrifying things like AI and wars and all the rest of it. This excites me. Well, thank you for turning it back on me, which you're not supposed to do, Sarah. That brings us to the end of our first ever live podcast. I thought it was a lot of fun. It was brilliant to have the audience actually reacting. Thank you so much for supporting Zoe, many of you from the very early days. Thank you for being in the audience and listening to us.

And that brings us to the end. Thank you very much. Professor Sarah Berry here. We've all experienced that familiar 3pm slum, that moment where your energy dips and you find yourself aimlessly rummaging through the kitchen for a quick fix. Biologically, that typically happens because highly refined soft textured processed foods can call rapid sharp peaks and subsequent drops in circulating blood sugar.

Our data shows that these kind of sharp drops can actually leave you seeking out more energy, forcing you to ride a metabolic roller coaster that can drive people to consume an average of 300 extra calories later. in the day. To address this challenge, the team developed the Zoe Gut Health Bar. It's a snack bar built with over 10 distinct plants formulated by our scientists to offer high plant diversity. When making this bar, our primary objective was to break the roller coaster cycle. We prioritise the food matrix, leaving as many of the natural plant structures as intact as possible. Because the structure isn't broken down by heavy processing, the nutrients enter your system at a much more measured, predictable pace, supporting a steady release of energy.

And we topped it with real dark chocolate or raspberries and goji berries, proving that prioritising your gut health can also hit the exact right note you're looking for in a snack. Find out more about the gut health bar at zoe.com forward slash snack bar.