Inside Tim Spector’s weekly food shop: 6 grocery rules to lower your blood pressure, cholesterol, and heart disease risk with Prof. Tim Spector and Prof. Sarah Berry

Supermarket shelves are full of foods promising to be healthy: high-protein, low-fat, gluten-free, sugar-free. How do you know what's true?

Today, Professors Tim Spector and Sarah Berry, world-leading experts in nutrition and diet, share the six rules they use for their own weekly grocery shopping. They cover which food labels are worth trusting and which are just marketing scams, how to make snacking a part of a healthy diet, and why your daily staples, like bread, matter more than the occasional treat.

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Jonathan: Tim, is it true that some breads are healthier than others?

Tim: Definitely.

Jonathan: Are most kefirs and kombuchas in the supermarket healthy?

Tim: Probably not.

Jonathan: Sarah, do you buy many products that advertise themselves as sugar-free?

Sarah: No.

Jonathan: Do you use front-of-pack nutrition labels to guide your shopping choices?

Sarah: Partially.

Jonathan: Have you changed what you buy each week since joining ZOE?

Tim: Yes.

Sarah: Absolutely, yes.

Jonathan: And finally, Tim, what's the biggest thing that people get wrong when they're doing their weekly shop?

Tim: I think it's being fooled by those labels on the front with ridiculous health claims — high protein, low fat, low sugar, low calorie. They're the things most people get wrong, and they get attracted to them.

Jonathan: When I walk into my local grocery store when I'm going to do the shop, I can sometimes feel completely overwhelmed. I want to buy the best foods for my health and for my family's health, but there are so many options today. So for instance, if I want to go and buy yogurt, which I know from you two can be a healthy option, there are rows and rows and rows to choose from, and I can't read the ingredient list for all of them.

Today I'm hoping we can go behind the scenes and get a sneak peek into your shopping carts and understand what world-leading nutrition scientists actually do when they have to go and do the shop. Tim, why are there so many options in shops today? I feel like when I was young, it was nowhere near as bad as this.

Tim: Most big supermarkets have 30,000 or more items, some up to 50,000, which is just incredible. And I think it's quite important to put this into an evolutionary perspective. Just 100 years ago, or even 70 years ago, there was virtually no choice in what you ate. It was what there was in the house or what there was in the village.

There wasn't this concept of waking up every day and going to the shops and saying, "Which of these thousands of items am I going to eat today?" I think we're suddenly faced with ridiculous amounts of choice, and we tend to go for the unhealthy, sparkly, shiny things that marketing is telling us to buy.

I think this is where the manufacturers are doing such a marvelous job on marketing, and making us buy things that we wouldn't normally eat.

Jonathan: I feel we're all convinced that having more choice must be good. So isn't it just a good thing that there's now this enormous variety of different foods in the supermarket?

Sarah: I think it's actually a double-edged sword. I do think there are some benefits to it. The things that I'm now seeing on the shelves compared to when I was younger, 30 or 40 years ago, there's an enormous new variety that's exposing us to all different types of fibers, polyphenols, bioactives, and different tastes.

So that's one good aspect of it. Another benefit is that by having the variety that we have, we also have the opportunity to offer different price points according to people's budgets. The majority of people have very little expendable income left for food, so those choices are often based purely on budget.

And we know the heavily processed ones tend to be about 55% cheaper than the minimally processed ones. So yes, we're offering more variety, but I do think we're therefore offering a variety of foods that are often a lot less healthy than if we'd narrowed it down to the original types of foods. As an example, let's go back to when I was younger.

You had your full-fat yogurt, your natural kind of low-fat yogurt, maybe a fruit-sweetened yogurt. There wasn't the array that we have now. So yes, there are some healthier ones, but there's also a lot of incredibly unhealthy ones.

Tim: Yeah, I think psychologists tell us that if you have nearly infinite choice, you make the wrong choices. You're overwhelmed by it, and you tend to go back to the same trolley. I was filming a TV series where we were going into people's supermarket trolleys and asking them why they'd bought that, and they'd just say, "Well, I always buy it." We're all guilty of it. We've all done it. But it's really good to highlight that there's generally always a healthier option than the one you have in your trolley.

Jonathan: And has this explosion of variety meant that now there's vastly more healthy choices available than in the past?

Sarah: I think it depends on the food category. We're seeing a real explosion in pulses, for example — beans, lentils — that we just didn't have in the past. I think that's fantastic. But then we're seeing an explosion in other food categories where I think you're having a lot of doctored foods that I certainly think are less healthy.

Tim: I don't think proportionally it's changed. Yes, if you're going there specifically to find a healthy food, a great example is that in ten years the whole range of fermented foods has changed dramatically. But it hasn't changed proportionally, because there are more ultra-processed foods and low-fat, high-protein variants of other foods as well.

Jonathan: So I'd love to come back to one of the quickfire questions, Sarah, where I asked about looking at food packaging — the label that's on the packaging. When you're going shopping and deciding what to buy, do you use those claims on the food packaging to judge how healthy a food is? Let's run through a couple. Imagine you're in the shop and you see a whole row of products, and some say in big letters "low fat," another says "no fat," and another says "full fat." Will you always buy the one that says low fat?

Sarah: It would totally depend on what type of food it was, because not all fat is equal. If it was yogurt, for example, I know that the type of fat in yogurt — even though it's saturated fat, because it's fermented fat — is not unhealthy for us.

Take extra virgin olive oil, or nuts and seeds — their front-of-pack traffic light would show a big red for total fat. If, however, it was something like minced meat, I would opt for the lower-fat version, so you can get 5% or 2% minced meat, because I know the saturated fat within minced meat is not good for us.

So it's very nuanced, and that's why I do think "low fat" or "no fat" isn't helpful. Also, based on the evidence out there, many people are selecting low fat not necessarily for health reasons — i.e., low fat means less saturated fat means less cardiovascular disease, which is what I think of as a nutrition scientist — but because they think it's going to help with weight loss. The evidence from randomised controlled trials is really clear that selecting low-fat foods over full-fat foods does not result in weight reduction.

Tim: The latest US guidelines have changed their view of fats. They're basically saying there's no advantage to low-fat foods in general, and that it's all about the ratios — which is where the UK and the rest of Europe should really go, and they're not. So we're terribly behind, and that's reflected in the labels. No nutrition scientist really believes that fat itself is bad for you, and yet that's all over our labels and our foods.

I think there are some rare exceptions, but in general, personally, I ignore anything that says "low fat."

Sarah: And there's also the issue of: by taking the fat out, what are they replacing it with? Particularly if it's a processed food — it's actually the fat that carries the flavor of food.

Jonathan: For the two of you, when you're in the supermarket, almost the only time you'd care about a label saying "lower fat" is with meat — minced meat, red meat — and in all the classic places I'd think about, like cheese and dairy. Actually, if it said "low fat" or "no fat," not only wouldn't it make you choose it more often, you might well be going in the opposite direction.

Sarah: Absolutely. But I believe fat has an incredibly important role to play in our diet — if you have the right type of fat, you're actually increasing the healthfulness of your food. Often, by saying a product is low fat, except for our mince example, you're stripping out healthy fats — your mono- and polyunsaturated fats, which we know are so important for our health.

Tim: And you're replacing them with starches and sugars. That's usually what they're doing, which aren't great for your blood sugar levels, and just make the whole thing sweeter.

Jonathan: So I can already throw away half the products in the supermarket because they've got a massive label saying "low fat" or "no fat." Can I come onto the next really big one — sugar-free, which I also see all the time. Are you more likely to pick that versus the product next to it that doesn't say sugar-free?

Sarah: It depends. We have to think of sugar as two different types. There's sugar in its natural context — fruit that has sugar contained within the structure of the fruit, for example. We call that intrinsic sugar. And then there's added sugar, separately. In the US, the label actually shows how much added sugar there is versus intrinsic sugar. If I were in the US, I'd look at the back-of-pack labeling for that.

But in the UK, we can't do that — we just know how much total sugar there is. If it says "no added sugar," then yes, I think that's a healthier option. If it says "reduced sugar" or "low sugar," does it still have a lot of added sugar in it? I won't know.

Tim: But for me, Sarah, I'd be really suspicious that it was just full of artificial sweeteners that they've replaced the sugar with, and that's why they're using the claim.

Sarah: Good point. Let's take full-sugar Coke versus no-sugar Coke. If you remove the sugar from full-sugar Coke, you're saving about 130 calories. But what's in that no-sugar Coke? Depending on the country, different sweeteners — ace-K, aspartame, saccharin, sucralose. So you're replacing it with something else. Again, which is better?

Tim: Yeah, I think the Coke example isn't fooling anybody — it's pretty obvious what you're drinking. I think it's things like yogurts, desserts, sports drinks, or other juices where we're being fooled, because they're keeping that sweetness level up and adding chemicals that we know may have a detrimental effect on our gut microbes. So for me, it's a bit of a red flag.

Jonathan: And it's a red flag for you because sugar-free probably means they've put in a whole bunch of sweeteners and other artificial things, but they're not being honest about it. Is that what you're saying?

Tim: Using Sarah's caveat, it depends, because there might be some fruits that give enough natural sweetness. But in general, it's a sign that they've probably added other stuff that's really hard to find — you have to use a magnifying glass on the back of pack to see all those sweeteners and additives.

Sarah: To pick up on Tim's point — if something's had an ingredient taken out, you really have to think about what's been put back in to maintain its texture, structure, taste, and functionality. That's why we need to be a little cautious. Sometimes the fat or sugar is taken out and something even healthier is put in, like certain fibres, but that's rare. Typically, it's swapped with something that isn't going to be healthier for you.

Jonathan: Let's move on and talk about some of the other labels I see all the time. Maybe we start with gluten-free. I think a lot of people see a gluten-free option and think, "This is healthier." Tim, how do you respond to seeing that sticker on a product?

Tim: Generally, I'd avoid it, because it means it's gone through extra levels of processing to make sure there's absolutely no wheat in it, or anything else that could trigger a problem for someone with celiac disease.

Although I have seen gluten-free water, so it's used in some countries to ridiculous levels. When gluten was at its height about five years ago, it seemed to have slightly died down now, this gluten-free trend. It was mainly used as a marketing thing — obviously 1% of the population has a real problem with gluten, possibly another 1% are intolerant of it. But for most people, it's a marketing tool, and they've created foods — usually highly processed foods — to exploit exactly that. The only exceptions are things like pastas. Rather than having wheat pasta, a traditional durum wheat one, you have a whole range of gluten-free ones made with lentils or chickpeas or other variants, which are fine for celiacs to consume, and are generally fine.

Jonathan: So you would eat those?

Tim: Yes. In most cases, they're not highly processed.

Jonathan: But gluten-free bread?

Tim: I've tried it, and it's pretty horrible. Sorry to anyone with celiac disease who has to have it, but unless you really need to, I'd generally avoid it.

Jonathan: We've got to talk about protein now. I don't think I saw any stickers about protein ten years ago in the supermarket. I was on holiday in Portugal this summer, and the supermarket there was full of stickers talking about high protein.

Tim: Wow.

Jonathan: So if you see a high-protein sticker, is that a sign that something is healthy?

Tim: Absolutely not, no. They've done surveys — and we've done some ZOE studies to show that if there's a protein sticker on that food, around 70% of people will regard it as healthy, whatever else is in it. It's like a super-sign saying, "Buy me." People have been driven by this huge tsunami of information telling them how amazing protein is — how it's going to give you big muscles, help you age better, prevent all kinds of problems, reduce disease — and this is just hype. 90% of people are not protein deficient.

But nevertheless, manufacturers will carry on. If it sells products, people will keep putting it in there. There's generally nothing too wrong with protein itself — it's about what else it's replacing on your plate, and what else is in there. A lot of the time, when they've added protein to ultra-processed foods, they're often increasing the processing, which is generally not good. So I try to ignore those protein messages. Doesn't mean they're all bad, but some of them are. What do you think, Sarah?

Sarah: I have a 14-year-old son who's just joined a gym a couple of months ago and has never looked at food labels or shown any interest in food, and now regularly comes home with these snack bars — all different types. He's like, "Mum, I've got a really healthy snack bar." I ask why, and he says, "It says it's high in protein." This is a 14-year-old being brainwashed, I don't know by what — TikTok, obviously — into thinking that as long as something has protein on it, it's healthy.

Jonathan: And when he picks out products and says, "This is healthy," how often is he right?

Sarah: Oh, rarely. Often these snack bars, when you look at the ingredient list on the back, have all sorts of ingredients — lots I haven't heard of. That doesn't necessarily mean it's bad, but in this case, many of his snack bars have so many synthetic ingredients, and very little whole food, healthy fats, healthy protein, or fibre. Not always, but in the case of what he's picking.

Tim: Most of these high-protein claims come on high-risk ultra-processed foods, and it's so easy to add — you just add a bit of whey protein, which is a waste product from the dairy industry. It costs nothing. They pour it in, and suddenly they can double their sales. It's a scam, basically.

Jonathan: What about when I see it on my tin of beans? I've noticed for the first time that my tinned beans have started to say "high in protein." Should I be worried about that?

Sarah: Assuming it's just a tin of beans, absolutely not. The protein in pulses and beans is an incredibly healthy protein. You're also getting fibre and other micronutrients with it — it's part of the original plant. I'm assuming these are beans without some sort of sauce added.

Jonathan: No, just in a jar or a can — kidney beans, lentils, any sort of beans. I have noticed they've started to have a sign on them saying "high in protein," and I didn't see that a few years ago.

Sarah: I think that's fabulous, because lots of whole foods that are high in fibre and protein wouldn't typically put that on their label, and yet that's an incredibly healthy source of protein, fibre, and micronutrients.

Tim: I think any manufacturer now is daft not to put protein on the label, and what we're seeing is some healthy foods finally getting round to it, so people can see that rather than eating unhealthy meats, whey protein, or processed snacks, you can have a can of beans.

Sarah: But I do think we're being a little bit down on labels. If you use them in the right way, in most instances you can make a reasonable call on the healthiest version — not necessarily from the front-of-pack labeling we've talked about. If you were to look at two crisps, say Kettle Chips versus—

Tim: Monster Munch.

Sarah: Monster Munch, great example. Nutritionally they'd be quite similar. If you looked at the back of pack, you'd first get the nutritional profile — calories, fat, fibre, protein, salt, sugar. But the ingredient list is slightly different. For Kettle Chips, very simply, you'd see potatoes, sunflower or rapeseed oil, and salt. For Monster Munch, I don't know off the top of my head, but I'd imagine there are all sorts of reconstituted starches.

Tim: Most Pringles varieties have over 30 ingredients.

Sarah: So in that case, the label can be useful and helpful for people.

Jonathan: So Sarah, I think you're now pulling us onto the second part of the podcast, which I'm really excited about. You've said, "Here are all these labels you both ignore," but you've also brought six rules to help us navigate the grocery aisle, and I'd like to go through them each in turn. I know the first one, rule one, you both agreed on: check for hidden ingredients. Sarah, could you help us understand what that means and how you do it?

Sarah: What that means is that the majority of our food is now processed and has added ingredients — some healthy, many unhealthy. You won't necessarily know that from the front of pack, so it's a case of taking it off the shelf, turning it around, and looking at the back-of-pack label. There you have two different labels: the nutrient profile — calories, sugar, fat, protein, fibre, and so on, slightly different in the UK and US but broadly similar — and the ingredient list, which lists ingredients with the biggest at the top and smallest at the bottom.

What you often find is that ingredients added in tiny amounts, but still significant for health — additives, sweeteners, colorants — are at the bottom. I think the most helpful things to look at on the nutrient profile are how much fibre and how much added sugar are in there. From the ingredient list, I'd look at how many whole, healthy foods are near the top.

If I was buying peanut butter, I'd expect peanuts at the top of the list. Some peanut butters are just peanuts, salt, and a pinch of sugar. Others have other oils, like palm oil, coming higher up the list, with peanuts second — showing that peanuts isn't really the main ingredient.

Jonathan: Do you check for hidden ingredients for every single thing you choose in the supermarket, or particular products? This sounds like a lot of work.

Sarah: I actually rarely look at back-of-pack labeling, because I take the view that if you can see the food through the packaging, and it resembles the original food it came from — take crisps, for example, if they look similar to a potato that's just been sliced — then I'd assume it's reasonably healthy. I'm making big assumptions here. If it's a crisp like Wotsits, cheese puffs, that's where I'd start to look at the back-of-pack label.

Jonathan: And Tim, what products do you worry about when checking for hidden ingredients?

Tim: Especially when I'm abroad, finding a healthy yogurt can be difficult. In the US, for example, it's really hard to find a full-fat yogurt without sweetener or vanilla in it, and you can't always tell from the front. In Spain, what seems like a normal yogurt often has a bit of sugar or sweetener, and you have to look at the back.

You can buy tomato sauces with added sugar, whereas I just want tomatoes, oil, and maybe some salt. Often it's these additions of sugars and salts to things you wouldn't expect, or sweeteners, that particularly worry me — it tells me I'm not getting a high-quality product. I just want the more natural one.

Sarah: I think breakfast cereals are another great example. Drinks, smoothies too. You go to the breakfast cereal aisle, and it now dominates nearly a whole aisle — a great example of huge choice, but the variability in cost and healthfulness is enormous. In the granola aisle, you can get an incredibly healthy granola, and then some others that are—

Tim: Everything's fake in them.

Jonathan: Could you help us understand? I can see this is a real thing for Sarah. What are you worrying about when trying to find the right granola?

Sarah: I'm looking for one with minimal whole-food ingredients — chopped nuts, seeds, dried fruit, oats. You can make a really good granola with just those ingredients — I make one at home. Other granolas have lots and lots of ingredients. That's not necessarily bad, because it can increase plant diversity, but they also often have lots of additives we don't yet know the impact of on our gut microbiome and health — emulsifiers, some of which we know aren't so healthy, or modified starches added for texture and taste.

Tim: And often salt and artificial sweeteners too.

Jonathan: I remember being blown away a few years ago that a cereal I thought was super healthy, because of wonderful branding about coming from some farm and looking really pretty, had loads of added sugar in it. I'd never even looked at the back of the pack — ingredient number three was about 20% added sugar. Is that unusual in a breakfast cereal?

Sarah: No, absolutely not. The ones marketed towards children are where we also have a big problem — many have lovely, fun cartoon characters. My kids are in their teens now, but when I took them to the supermarket when they were younger, the cereal I ended up leaving with wasn't the healthiest — it was the one where I lost the will to live and gave in.

Tim: Which are around 30% sugar, sometimes more.

Jonathan: 30% sugar.

Tim: What I've found recently, talking to other people at the supermarket, is that middle-aged people are still eating the breakfast cereal they had as kids. We form these unhealthy habits and never question why we're eating a cereal that's 30% sugar — it's just habit. I think it's a really important point.

Jonathan: I'd love to move to rule two now: don't fear fats. Sarah already talked about how low-fat products can often be less healthy than the full-fat version. What fatty products do you go for when doing the supermarket shop?

Tim: I spend a long time in the cheese aisle — we all know that's very fatty, and there are still a lot of misconceptions. A lot of family doctors tell people to avoid cheese because it's bad for your heart, but all the epidemiology evidence suggests that's not the case — whether it's the fermentation or something else, it's not harmful, and possibly beneficial.

So all the dairy products I generally go for are full fat. I also go for the nut aisle, the seed aisle, and of course my staple go-to is olive oil, which is fat and about 13% saturated fat — but we know that's incredibly healthy. So all this old-fashioned advice about avoiding fat is basically wrong. We need lots of fat in our body, and the key is swapping out unhealthy fats — which have been used in ultra-processed food for decades — for healthy ones.

Jonathan: Anything you'd add, Sarah? Is there a lot of fat making its way into your basket?

Sarah: Yeah, absolutely. I love fat, and I see including healthy fats as a great way to improve the healthfulness of my food. We have to move beyond the perception that high-fat foods are fattening for the body, or bad for our health in terms of cardiovascular disease and cholesterol. We have to take a more nuanced approach. We know the type of fat matters, and it's even more complicated than that — it's the type of food it's in. Saturated fat in cheese, like Tim said, doesn't have that negative impact. Saturated fat in butter or red meat does.

But the vast majority of packaged foods on our shelves actually have quite healthy fat sources — typically made with rapeseed or canola oil, or, in the US, soybean oil. These are very high in mono- and polyunsaturated fats, with a similar composition to olive oil — not as healthy, just a caveat — but it means that often, removing that fat removes a potentially healthy component of the food.

Jonathan: Can I ask specifically, Sarah, what you put into your basket? You've mentioned cooking oil — what do you cook with at home?

Sarah: I get different oils for different purposes. I buy extra virgin olive oil to drizzle on salad or on top of food, like pasta when I've finished cooking it — it's got heart-healthy fats but also lots of polyphenols, which are really good for our health. Extra virgin olive oil is very different from normal olive oil — they have the same fat composition, the same saturated/mono/polyunsaturated fat, but extra virgin retains all the wonderful bioactives like polyphenols.

For cooking, I typically buy rapeseed oil — canola oil in the US — or a bog-standard vegetable oil, usually mainly rapeseed or canola, sometimes with a bit of sunflower or soybean oil. It's very high in polyunsaturated fats, which are really good for heart health and cholesterol, and has a decent amount of monounsaturated fats too. It's a bit more stable for cooking than extra virgin olive oil, and has a neutral taste. If you like the taste, go for extra virgin olive oil — but remember, heating at high temperatures destroys some of those polyphenols. Extra virgin olive oil is also expensive, so for people who may not have the budget to use it for all their cooking, rapeseed or canola oil is a really good alternative.

Jonathan: Let's move to rule three: snacks are not the enemy. Sarah, I know you're an avid snacker — so am I. But I've always felt that snacking was unhealthy. What does the science say, and do you buy snacks in the supermarket?

Sarah: I absolutely buy snacks, and the science shows that snacking isn't unhealthy, depending on what you snack on. In the UK, the US, and many countries, about 20–25% of our energy comes from snacks. For people who do snack, I believe it's one of the simplest dietary strategies to improve health. As proof of this, I conducted a trial at King's some years ago where we asked people to consume 20% of their calories from either nuts or typical UK/US snacks. We monitored them for six weeks. At the end, the improvement in intermediary cardiovascular risk measures — blood cholesterol, blood vessel function — in those consuming nuts versus typical snacks equated to a 30% reduction in cardiovascular disease risk. That's huge. It really shows the power snacking can have.

Jonathan: And Sarah, what do you put in the basket?

Sarah: I don't actually get my snacks from the supermarket anymore — and this is going to sound like a sales pitch, which it absolutely isn't, but it's true to what I do now at home. I have ZOE snack bars delivered, which I purchase from ZOE. These are snack bars that Tim, myself, and the incredible team at ZOE created, based on our knowledge of what constitutes a healthy snack. So now I know I'm using my snacking to have the healthiest possible diet I can.

Jonathan: For someone listening in a country where those bars aren't available, what would you have added to your basket a year ago, before this existed?

Sarah: There are so many opportunities for healthy snacks — nuts, seeds, fruits, vegetables, but also others we might not think of. You could even snack on leftovers from a healthy meal the night before. Popcorn, yogurt, cheese on wholegrain-style crackers — these are all healthy ways of snacking. We have to get out of the perception that a snack is a pre-packed snack bar, chocolate bar, or crisps. It's an eating event between meals. If you're having lots of cookies with your tea every day, that's not going to be healthy — changing that for any of the things I've mentioned can have a huge impact on your diet.

Let's move on to rule four: staples matter most. Tim, what does that mean?

Tim: It means the health consequences — good or bad — of what you're eating matter much more for the things you have every day than for something you might have once a week or twice a month. For most people this includes milk, yogurt, bread, meat, bacon, eggs, sausages — these kinds of things. Small differences in these make a much bigger impact on your long-term health, so sorting out whether you can make your staples healthier is really important.

Jonathan: The first staple I think about is bread — something you buy every week, it goes off, you keep replacing it. I never thought about bread before I met the two of you — I think I used exactly the same loaf for 20 years — but I now know not all breads are equal.

Tim: Absolutely true, and this is a key staple across most countries. Just by changing this a little, we could do wonders. When you go to a supermarket aisle full of bread, you see a huge range — everything from the classical white "Wonder Bread" type that stays the same for a month, to a granary sourdough artisan loaf you're paying five times more for, and everything in between, with confusing labels like wholegrain, wholemeal, multi-seed, multigrain, high fibre, and so on.

Even I struggle to work out what I should be getting just by looking at the outside of these products. I'm obviously not going to get the cheapest white toasting loaf, full of chemicals and additives with very little fibre. But then some that look healthy might just be dyed brown to look as if they've got more wholegrains in them. All kinds of tricky things to navigate. The only way I've found round this is to go to the ingredient list on the back, and look at the ratio of carbohydrates to fibre — I'm looking for a ratio as close to five as I can get. On the back you've got protein, carbohydrates, and fibre given in grams, and essentially you want something with a high amount of fibre and a relatively low amount of sugar.

Jonathan: Is low fibre the only thing you're watching out for in bread?

Tim: It's not the only thing. I'm also looking for other additives. If it's made using the fast, rapid chemical method called the Chorleywood process, you often get glues and emulsifiers, salt, sugar, colorants to make it look attractive, things to keep it spongy, preservatives, and things to stop the slices sticking together in the fridge.

Jonathan: I have to say, you're making it sound more desirable the more you go on — glue in my bread!

Tim: Well, they're designed to be super tasty — who doesn't like a nice bit of toast and jam straight out of the toaster? They're designed to be delicious, and, as Sarah and I have investigated, hyperpalatable — the right amount of sugar, fat, and salt, in just that combination.

Sarah: But I think, Jonathan, staples are a fabulous way to improve the healthiness of our food without totally changing our shopping basket. Bread, eggs, dairy — particularly milk — pasta, rice, potatoes. These are six food categories most people will have at least a few of, if not all six, consuming one or two of them every day. There's some really good evidence showing that just switching the type of ones you have can significantly improve your health.

Jonathan: Sarah, what have you swapped?

Sarah: I like bread, potatoes, rice, and pasta. I know the white, non-wholegrain versions of these aren't the healthiest for me. Sometimes I still have them — if I'm hungover on a Saturday morning, I want white bread with lashings of butter and some bacon.

Tim: Oh, Sarah.

Sarah: I know it's unhealthy, but I'm sorry — I'm hungover, Tim, so I don't care. Not that I'm advocating anyone listening to be hungover or drink.

Tim: And you're not hungover every day either.

Sarah: Oh gosh, no — it's just after I've done a podcast with you, Tim, I need it! But where I can, I've tried to swap to wholegrain. We know the lack of wholegrain in UK, US, and international diets is one of the biggest problems for health, because wholegrains have lots of fibre, micronutrients like iron and zinc that a lot of people are quite deficient in, and healthy protein.

They're so much healthier than the white version. There's fantastic new research just out showing that in the UK, and broadly similar in the US, if we changed our staples of white rice, white pasta, and white bread, we'd go from an average wholegrain intake of around 16 grams a day to 75 grams a day — and at that level, you reduce your risk of all-cause mortality, type 2 diabetes, and cardiovascular disease by around 10%. This isn't telling people who don't eat bread to start — it's that, based on typical consumption patterns in the UK and US, changing our bread would add at least about 20 grams of wholegrain. Changing white rice to wholegrain rice, and white pasta to wholegrain pasta, would each add about another 10 grams — so we'd be increasing wholegrain intake by roughly 50–60 grams overall. But you're still having your sandwich, your pasta, your stir-fry. And potatoes — keep the skin on, it makes a huge difference to fibre and micronutrients.

Jonathan: That's amazing. So just swapping from the white version, which is what I grew up with — pasta, bread, rice — to the wholegrain version, which generally looks brown and has the original plant there, transforms my health outcomes without having to change what I eat.

Sarah: Absolutely. You don't have to do it for all of them — I personally can't stand brown pasta, but I've changed my white bread to wholegrain. That's where the biggest effect is anyway. And going from white grains to wholegrains, there's almost no difference in price, so it's accessible and affordable for everyone. Those small changes do add up.

Tim: I can't stand brown rice, so I've changed to bulgur wheat, which is actually much higher in fibre and protein. Quinoa is even better than brown rice too — there's always a nice, easy swap for most of these. That's the point.

Jonathan: I'd like to come to rule five: ferment deception. Tim, fermented food is having a moment around the world — kefir was unheard of in the US and UK just a few years ago, and now there are loads of options. What should people look out for, and why do they need to worry about being deceived with their ferments?

Tim: It's finally come of age that people think fermented food is good — it's made it into the US dietary guidelines, saying we should be having regular fermented foods, and hopefully the UK will follow in about ten years. This means you should be trying to get multiple types of ferments in your diet.

The ones that are still good include cheese — we forget that's a good ferment, and that hasn't really changed. Possibly for vegan cheeses you have to be a bit careful, because a lot are highly processed, and frozen pizza cheese and cheese slices are to be avoided. All other cheese is pretty good — I'll eat standard cheese, whether Gouda, cheddar, or even cream cheese; you don't need artisan cheese all the time. As part of a study I did for my book, Ferment, we looked at 70 different products, and even simple cheeses had multiple microbes in them — they're live. Even something as processed-seeming as Philadelphia cream cheese had three species of microbe. Only things like Kraft slices had absolutely nothing. As you go more artisan, craft cheese, raw milk cheeses, you get a bigger variety of microbes, but you're still getting plenty with standard cheddars.

For yoghurts, I always go for a full-fat Greek-style yoghurt and check there's nothing else added. I don't go for the super-high-fat ones — I find them slightly difficult to eat; whatever the cow is producing is good for me. For kefir, I sometimes make my own, but since I travel a lot, I often buy it — if I can get the artisan versions made with real kefir grains, I will, but they're hard to find in supermarkets. Most supermarket ones are a cross between yogurt and kefir, but the good news is we've tested them and they do have live microbes — three or four times more than yogurt. Generally, the ones without fruit or sugar are good; anything with fruit or sugar, I avoid, because I don't know how that affects the live microbes.

Jonathan: So this is a big warning for you — when you say kefir, you mean actual kefir, not a fruit yogurt with a kefir label on it.

Tim: Exactly right, because to get a kefir label, you often just have to add twelve specified microbes that are kefir cultures — "contains kefir cultures" can be easily added to any old rubbish.

Jonathan: Can I ask a similar question about kombucha, which I've seen explode? What on the back of pack would make you not drink a kombucha? I've noticed they seem to be stuffed full of artificial sweeteners and other things. Would you buy any kombucha? What makes you say yes or no?

Tim: Yeah, I do like kombucha. Generally, most kombuchas have some sugar in them, but it's a fifth of the amount you'd get in a Coca-Cola, so relatively they're much better for you, and we know they have health benefits. If the sugar levels are relatively low, they won't counteract the microbes. But I worry when there are lots of extra additives, food colorings, flavorings, and artificial sweeteners, because we know artificial sweeteners have a negative effect on gut microbes — and one of the reasons for drinking kombucha is to improve your gut microbes, so that's a bit of a dilemma. Many products do have these, so look for the pure ones. Also, if you can see sediment in a kombucha, it's likely to be real and live, made from actual kombucha cultures rather than just added.

Jonathan: Amazing. I'd like to move on to the sixth and final rule, which I know you said was the most important: buy more plants. Having spent so much time with you both over the last few years, I'm totally on board with eating at least 30 plants a week, but there are still a lot of choices that trip me up. What is this 30-plants-a-week target, Tim?

Tim: Our science at ZOE has told us that 30 is about the right number to aim for. We don't know if there's an upper limit — it could be that higher is better, and we're currently investigating that. But we know people who eat 30 plants a week regularly achieve much better gut health and feel better. The average person in the US and UK is having perhaps 10 or 12 different plants a week on average, so we're increasing that two- or three-fold — which has the side effect of increasing fibre intake as well as nutrient and polyphenol intake. It's a nice, simplistic idea that has a wide variety of other effects on the body, and it resonates with the public, in contrast to most countries' official advice of five fruit and veg a day, which can always be the same ones. That's what people generally did, and they often weren't particularly healthy ones — orange juice, or lots of bananas, or things like that.

Jonathan: That sounds tough — trying to get 30 plants a week. How does that shape what you actually buy?

Tim: To get my 30 plants, I make sure there are some easy wins. First, I get bags of mixed seeds and add that to a bag of mixed nuts — combine those two and you've got about 10 plants there; I keep them in a jar at home, my "diversity jar." Fresh herbs are great too — everything from parsley to watercress, things you can just add to salads. I make sure my spice drawer is really full, because a teaspoon of spice has been shown to improve gut health and counts as one of your plants. I'm also always trying to buy things of different colors — most people's shopping trolleys are full of iceberg lettuce; we need to change that to get something more colorful and nutritious, and that's another way of getting to 30.

Jonathan: Sarah, what do you include in your shop to get all these plants?

Sarah: I have mixed nuts and seeds for breakfast with my yogurt — that ticks a box. But the rest of the time, my choice of vegetables and fruits is largely determined by what I know my kids will eat. Yes, I know we should keep exposing them to different foods, but the reality is I also work full time, two jobs, and don't have time to disguise carrots or chickpeas. If it wasn't for the ZOE products I have, I don't get to 30, and neither do my kids. I try now to add in herbs and spices, which have a really important role to play — I just add them to a dish, and my kids don't notice because it's not a big chunk. I add more garlic and onion as a base to ingredients, and I try to add fresh tomatoes alongside the tomato pasta sauce they like. So there are things like that I do, but it is quite hard, because we're used, as individuals, to cooking from a small repertoire of ingredients and meal choices.

Jonathan: It's really interesting — the one thing you two haven't mentioned that's been transformative for me is beans. You can now get them in a jar — before, they were always in a tin — and they're incredibly cheap. When you open one, you can put it in the fridge, no faff. I can have those instead of pasta or bread sometimes. They're amazing because they're so high in protein and fibre, so filling — for me, they've transformed the number of plants I hit within the week.

Tim: Another similar tip is getting sachets of pre-cooked mixed lentils, and you can also get mixed grains — a lot of the big supermarkets now do pre-cooked mixed grains, different types of quinoa, bulgur wheat, pearl barley, all ready-cooked. It just takes a few minutes, and you get not only high fibre but all those extra different plants. It's just about thinking about it when you're doing your shop — you can make it a lot easier for yourself.

Jonathan: Final question: if you were to suggest one underrated or cost-effective plant a listener could add to their basket this week, what would you suggest?

Tim: I'd go for beetroot. It's not a trendy thing, but it's fantastic for heart health, lowers blood pressure considerably, and can be cooked in lots of different ways — you can even ferment it and make it into a kraut. I used to hate it; now I love it, and it's always in my fridge.

Sarah: I'd go for mixed nuts. They're great to carry around as a snack, and you can add them to so many different meals — breakfast, stir-fries, there are so many ways to use them in everyday cooking. They're packed full of heart-healthy oils, micronutrients, and fibre. If I was ever to use the word "superfood" — which you know I hate — it's the one food I'd say could genuinely be classified as that.

Jonathan: Ooh, you got close to saying "superfood"! I thought this was a fascinating episode — we covered so much. The first thing I take away is that all those front-of-pack labels are, for you, reasons not to buy. High protein — no. Gluten-free — no. Low fat — no. Low sugar — no. All the things manufacturers put on to try to sell you the product actually make you skeptical. And then you came up with six rules you do use.

The first is check for hidden ingredients — you talked about yogurt as something to really check, and breakfast cereal, where two products can look almost the same on the front but one is genuinely healthy and the other stuffed full of added sugar and additives.

The second is don't fear fats — there's still this huge cultural fear of fat, hence all those low-fat labels, but you're both going out of your way to buy high-fat products I was told growing up were bad. Cheese, for example, can be a healthy food with live microbes inside it. Extra virgin olive oil is Sarah's go-to to spread on meals, and Tim cooks everything with it — which has convinced me to do the same. You're also cooking with rapeseed and canola oil, a lower-cost way to still cook with something healthy.

Rule three, snacks are not the enemy — changing your snacks can reduce your risk of heart attack and heart disease by 30%, which is huge.

Rule four, staples matter most, because they're the things you're eating over and over. Sarah, you said something amazing — that just swapping your traditional white staples of bread, rice, and pasta to wholegrain can transform your wholegrain intake and significantly reduce your risk of dying.

Sarah: Absolutely.

Jonathan: Which is quite something. Tim, you talked a lot about bread — another area where a lot of what's on the shelves isn't very good for you, and you're really looking at the ratio of carbs to fibre, ideally around five, and noting that most breads aren't close to it, and many have glue and other things in them that I personally don't want in my bread.

Rule five, ferment deception — it's great to see all these new fermented foods, but you've got to watch out, because just because it says "kefir" on it doesn't guarantee it's good. Interestingly, regular cheese can be a great ferment. On kefir, ideally you'd get an artisanal one, which is hard to find in supermarkets, but a regular plain one is good — as soon as you see fruit-flavored versions, like strawberry kefir, it's no longer a health food, it's something to avoid.

Finally, rule six, and the most important: buy more plants, aiming for 30 plants a week. Sarah, I think you had this amazing honesty that you'd find it really hard to do that just through what you buy in the grocery. We talked about a few tips — try beetroot, mixed nuts, beans in jars, and pre-cooked sachets of grains and lentils. All ways to make it easier, and all healthy products you can buy and put in your supermarket trolley.

Tim: It's a minefield out there, but you've done a great job to help.