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Jonathan Wolf
Welcome to Zoe Science and Nutrition, where.
Host
World leading scientists explain how their research can improve your health.
Jonathan Wolf
Eating a low quality carb when you're hungry is like throwing crumpled newspaper into the fire. The flames roar for a moment, but then they fade to nothing almost as quickly, leaving you in the cold. Over 80% of the carbs we eat are like that crumpled newspaper. You feel full in the moment, but hungry shortly after. Now imagine reaching for a sturdy log instead. The flame doesn't leap up in an instant. It builds slowly and stays warm throughout the night. And that's what you get with a high quality carb. Feeling full for longer. Carbs seem so simple when explained this way. But which are the good carbs? Are they better for breakfast or dinner? Can we mix them with something else to make them healthier? This complexity is confusing and celebrities peddling restrictive diets are making matters worse. Today, Professor Tim Spector sets the record straight. According to the latest research, Tim has written three books debunking diet myths, and today he'll give you the information you need to know to eat healthy carbs without restricting your diet.
Host
Tim, thank you for joining me today.
Professor Tim Spector
What a pleasure.
Host
So I don't think I really need to explain the rules to you, Tim. We are, as always, going to start with our rapid fire questions from our listeners. Are you ready to go?
Professor Tim Spector
Hit me.
Host
All right.
Jonathan Wolf
Are all carbohydrates bad for us?
Professor Tim Spector
No.
Host
Do we eat too many bad carbohydrates?
Professor Tim Spector
Yes.
Jonathan Wolf
Is a low carb diet a healthy choice for everyone?
Professor Tim Spector
No.
Jonathan Wolf
Could pairing your carb with another food make it healthier?
Professor Tim Spector
Absolutely.
Jonathan Wolf
Is there a time of day that's.
Host
Better for eating carbs?
Professor Tim Spector
For some people.
Host
And finally, what's the most common misconception about carbohydrates?
Professor Tim Spector
I think most people believe that all carbs are bad and that's absolutely not true. Some of them that contain fibre are the most essential foods we can eat.
Host
Well, I think that's hopefully what we're gonna do today. And I'll be honest, I find the topic of carbs quite confusing when I say the word. I was thinking about this as I was coming in this morning. I immediately think of this freshly baked loaf of bread, right? You can smell it, smells amazing. And then the delicious taste. And then, unfortunately, Tim, you've ruined it for me because I now know that it's followed by my blood sugar jumping through the roof over the next couple of hours. And at that point, suddenly I'm feeling tired and hungry or hangry as my family. But Tim, you've also told me that carbs aren't just bread and potatoes. So what is a carb and what is it that can make it unhealthy?
Professor Tim Spector
Well, a carb is a macronutrient. So in the old school world that we used to know, everything was divided into these three groups of proteins, fats and carbs. And most of the things we eat are mixtures of those. Rather than one thing, you don't actually eat a carb, you eat a plant. And that plant will have different amounts of proteins, fats and carbs in it. And within the carbs it's going to have different types of carbs in it. And some of the foods we eat, which you say, oh, that's a carby food, like, say, bread is also going to have some protein in it and a little bit of fat in it. So we tend to massively oversimplify, but that's what we've done in the past mainly through ignorance. And the food companies have liked it that way because it's made it very easy to, to sell products to us. Now I think we need to break down carbs into what they are, which they are essentially sugars that are either very simple, sort of moderately simple and really complex and, and long and hard to break down. So the, the simple sugars, like sucrose, you know, your table sugar, is a very simple carbohydrate. It's a very simple sugar. It means it only has a few bonds easily broken down and used by your body as energy. Then you've got the starches, which are slightly more complex storage forms of sugar which are joined together by bonds which can be broken down by other enzymes in your body. And every plant has these starches and we're designed to do them. So they break it down into simple sugars which are then released. Just takes a little bit longer. And then you've got the really complicated long sugars all joined together with lots of tight bonds that are called fibers. And these are sometimes really impossible to break down in the body and only by the gut microbes sometimes rather than ourselves, and they pass through the body. So you've got this complexity all the way from simple to very long and complex with very different effects on the body. So most people think of carbs as only the sort of sugary end ones. They forget that a lot of the healthy carbs are these complicated fibers at the other end. So they throw the baby out with the bathwater. So I'm not having any carbs. It's all rubbish. They're all deadly. Well, that's not true.
Jonathan Wolf
And could you give me some examples.
Host
Of what those like simple and starchy carbs are?
Professor Tim Spector
Well, a simple carb is like table sugar. It's like honey maple syrup, these things. You know, there's nothing, it's just. This is you and the sugar, right, Coca Cola, because it's got added sugars to it. So the sodas, they're having essentially table sugar or fructose, high fructose corn syrup, which is the sugars extracted from corn, which is virtually identical to table sugar, just a slightly different ratio. Again, a really simple sugar. So these ones give you that instant taste in the mouth. An example of a, of a starch, which is like this middle grade is when you might eat a cheese biscuit or cracker and you put it in your mouth and it's savory, you don't taste any sugar. If you keep it in your mouth, your enzymes in your saliva will break it down. That starch will become into these simple sugars and after it's been your mouth about 30 seconds, it will turn sweet.
Host
Let me get that straight. You're saying that I might have this cracker, like it's not a Sugar, but within 30 seconds of being in my mouth actually just like the saliva in my mouth has broken that down and turned it into sugar?
Professor Tim Spector
That's right, yes. And the same thing is if you're having some white rice or you're having a pasta or you're having a potato, they're all starchy carbs which are transformed fairly rapidly into sugars, but they're not sugar when they start. So it takes a little bit of work for our body to break them down. But often that's done really just with our saliva in the early stages of digestion. It doesn't take that much.
Host
This is one of the things that most shocked me when I started doing Zoe with you, Tim, because I'd always thought of rice as being this really healthy thing that you know, you had with sushi and that was so healthy, or you had it with some sort of Asian meal. And this was like much better than the food that I'd grown up with. And so I was completely shocked by this story that actually basically it turned into sugar almost immediately. Is that really what happens?
Professor Tim Spector
Yes, unfortunately it is. What you think is the more synthetic rice is like these so called parboiled rices or the Uncle Ben's style rice actually happens slightly slower because it's pre cooked, it's been cooked in two stages. But most rice particularly the sticky rices are really sugars and that's why in Japan you get these. Most of their candies are made out of these sticky rice and it is known for its sweetness. So, yes, white rice is a fantastic example of a very starchy food that converts very quickly into sugar, gives you a sugar spike in your blood and will have those consequences. And we used to think it was healthy. I agree. And, you know, before I got into this, that's exactly what I thought as well.
Host
And Tim, could you explain a little bit what makes it unhealthy? So you've described the way that, you know, either you're just literally eating something with sugar in it, or you're eating one of these starches and you're saying it turns into sugar fast. What goes on that makes that then unhealthy for us?
Professor Tim Spector
It's the way we react to the sugar rather than necessarily the sugar itself, which is bad because our ancestors were seeking out honey and other things with great relish. So when you have a sugary drink or a soda or a bowl of rice, white bread, you will see after about 30 minutes, a sugar spike in your blood. So your blood glucose levels will be going up very fast. And you can see these in these glucose monitors that anyone who's done Zoe will know about. And it varies in people how long and how high those sugar spikes are, but that then triggers production of insulin by the body to drive it down. And this is actually causing effort to the body. So there's a metabolic effort in doing this. And if this is repeated a lot of the time, some people find it hard to keep these spikes down. They're very sensitive. And we found this in the Zoe study, if you remember a few years ago. Now, tenfold differences between people like you and I in how we respond to a standard meal of a cookie or a muffin or whatever it is. So everyone's very different, but the people who suffer get these really big sugar spikes. That causes metabolic problems. That is working the body really hard all the time. And we think this causes low level inflammation and goes on to lead to metabolic disturbances, increased risk of diabetes and all kinds of other consequences, as well as short term ones, which we also showed it can make you hungrier. So that's the sort of catch 22 here is, yeah, okay, you have your little sugary snack to relieve hunger. What does it do? Gives you a sugar spike, Maybe you get a dip. After it, you're even hungrier, so you're eating more during the rest of the day. So long Term and short term consequences of having sort of free sugars everywhere without real food to, in a way to help mop it up.
Host
Every time I hear this story, it always slightly blows my mind, Tim. It's this idea that, like, eating the food now might actually make me eat more food later. You know, it's the exact opposite of how I was brought up. And I was thinking about this with my wife, you know, this morning, who has this very strong view that absolutely, you know, my daughter mustn't leave the house without having to have had a good breakfast, even when she's not very hungry, because, like, well, you know, how could she possibly, you know, go to school if she's not hungry? And I think about this idea that obviously you don't want anyone to go to school hungry. But there is this weird thing that eating the wrong food as you're describing, might actually make me hungry again in two hours time. And is this real science? Because it sounds crazy.
Professor Tim Spector
Yeah, it sounds very weird and it's against everything we've been taught by our parents, but it's absolutely true. And we've shown this in our Zoe studies quite consistently that people who have these big spikes and the dips afterwards, three hours later, they're consistently hungrier than people that don't. And they will consistently overeat, you know, by about 10 to 20% over the day compared to people who aren't having those sugar spikes. So it's now well known in the scientific literature and it's one of the big dangers of, you know, not worrying about sugars.
Host
You've mentioned, I think, a lot of metabolic diseases and inflammation. How does this tie into this epidemic of obesity that we've seen over the Last sort of 40, 50 years? Is this important or not really?
Professor Tim Spector
I think it is very important because as we shifted away from fats to carbs and sugars and starches in particular, and this was standard government health advice, we've been seeing increase in obesity in heart disease and all those consequences. And many studies have linked obesity to intake of these starchy carbohydrates and free sugars. So some of this is due to, say, sugary drinks, beverages, sodas, et cetera, which can account for about a quarter of our sugar intakes.
Host
A quarter of our sugar intake can be from these sugar sweetened beverages, you.
Professor Tim Spector
Know, so particularly more in children. So we thought we were sorting out, your child's a bit hungry or thirsty, give them something, but actually you're just making it worse by giving them these high sugar intakes. And also sensitizing children to even more sweet tastes and seeking out even more unhealthy foods. So I think part of it is the massive amounts of soda beverages we've been having that are sugar sweetened. The other is this real push by governments and health people and the food industry towards starchy foods rather than fats or fibre.
Host
And so what are. If I was thinking about this on my plate, you know, you've mentioned white rice and you've mentioned these sort of sugary drinks. What are the other big sources of these sort of unhealthy starchy carbs that someone listening might be putting on their plate?
Professor Tim Spector
Well, we're surrounded by them, really. Most of snack foods are starchy carbs. Your potato chips, Doritos, your Pringles. Most of the breads that we're having are highly starch, rich and very poor in fiber. And these are the staples, really. So most people are eating potatoes, rice, bread every single day. And you only have to ask a family doctor and say, when you've got your patients with pre diabetes or diabetes, what's their diet? It's nearly all potatoes, rice and toast, which they've been told was good because it's low fat.
Host
I think it's interesting because I think I was definitely brought up with a view. Well, that sounds really. I mean, a potato, after all, is sort of like a plant and it's taken out of the soil. You feel like you're doing something really good. I mean, I used to eat quite a lot of boiled potatoes and I didn't even really like them very much, but I felt, well, that's really healthy. And what you're saying is I could have eaten something really delicious that tasted sweet as I was eating it, because I'd have got the same effect, which is it's been turned into sugar in my stomach in just a few minutes anyway.
Professor Tim Spector
Exactly. So it's all about how quickly is that carbohydrate dissolved in your body, how quickly does it go? So there are even differences between types of potato. So you've got the worst, which is your. Do you like mashed potato, Jonathan? There was the artificial one smash, which was powdered. That was the ultimate in the quick fix.
Host
Is that right? You sort of get it instantaneously because it's being completely powdered.
Professor Tim Spector
Yeah. There's nothing for you to break down. It's all done for you. So then you've got normal mashed potato, then you've got boiled potatoes, then you obviously got fried ones, which are also easy and probably the best ones, you know, are a small jacket potato where you're actually eating the skin and then at least you're getting some fiber there. It's slightly harder to break it down, but they're all on a continuum. And generally the idea that potatoes are a healthy food for most people, that's not true. I mean, they're very good source of nutrition. But in the modern world, I think we're probably eating too much of them. We're too reliant on those, you know, bread, potatoes and white rice, and to some extent, pasta. Although pasta has some other advantages. It's got more fiber in it, it's got more protein compared to rice.
Host
And why are we eating so much of these sorts of carbs? Is it just because they're the things that we like the taste of?
Professor Tim Spector
I think it's a combination that they're comfort foods for many of us. I mean, white rice has a sort health halo to it. And you look at every health cookbook generally, you know, particularly vegetarian and vegan ones, they've got beautiful pictures of steaming white rice that look very tempting. And I think it comes from that. You know, you were saying earlier, you know, the smell of crusty bread when you go into a restaurant and the first thing they serve you, I mean, it is irresistible for. For most of us. And just knowing that it should be a, you know, more of a. A treat than a staple, I think is really important. Or you pick the right ones. You're fussy about which ones you're going to have and when. Because I'm not saying you should never have these foods. I'm just saying that if you're having them on a regular basis and you're susceptible, because not everyone is as susceptible, then it's a problem. So everyone should know about it.
Jonathan Wolf
And I think I've heard you talk.
Host
A little bit about. About the role the food industry might have played in this.
Professor Tim Spector
Yes, they're very keen to push these products because you can make them very cheaply. You can create powders so that they can be added to things. Ready Meals are instantly made with carbohydrates that store forever that, you know, you can add preservatives to and that keep you coming back for more. So what they like is the fact that the more you eat, the hungrier you get and the more you want them. And, you know, there are examples in these carbohydrate snacks. My favorite is always Pringles, but you can cut the name out if you're worrying about being sued.
Host
No, no, Go on. What was Pringles claim?
Professor Tim Spector
Well, they claim they're a potato snack, but actually it's made up of about four different plant extracts with, you know, rice and tapioca, and then they're molded. So basically they take the cheapest products they could use. The dregs of that, they dry it all up and then they stick them back together, glue them back together to look like a potato, and then they slice it up in these nice, these nice ways. And the average one has about 30 ingredients, if you look at the back of pack, which are flavorings, colorings, glues, emulsifiers to stick it together.
Host
And Tim, I seem to remember something like once you pop, you just can't stop. Is that. Am I thinking right?
Professor Tim Spector
That's right. And if anyone's done this, a test, it is very hard to just have one of them. And they've been created with these addictive properties, but they're combining the carb with salt and some fats as well. So they know that that combination produces this bliss point. So very often when we're talking about, you know, how carbs are used in big food, it's in combination with these other ingredients to give them that perfect bliss point where your brain just lights up with dopamine. And, you know, you go, ah, you know, isn't that nice? And it's a short hit, but you know, it doesn't last.
Host
That's crazy. So you get the hit, you feel good, then it falls away fast, and therefore you need the next Pringle and the next Pringle in order to keep it going.
Professor Tim Spector
And then you've finished the whole tube and that's it. Yeah. And you feel sick.
Host
That's amazing. So it's even faster than the description you were giving with the potatoes and the bread where I'm getting this big blood sugar spike. You know, it feels really good as I'm eating it. And then two to three hours, hours later, I'm really hungry and I'm having to go back again.
Professor Tim Spector
Absolutely, yes.
Host
Now, I feel like you've done nothing but tell us how awful carbs are so far. Tim.
Professor Tim Spector
Some carbs. Some carbs, Jonathan.
Host
Well, that's where I wanted to go, because I know that your very highly cited research has helped reveal the connection between the food that we eat, our gut health, and, like, our overall well being. How do we feel? And I know that within that you've also talked about how carbs can be good. So could you help us to understand now what is a good carb and why do we need it.
Professor Tim Spector
Well, a good carb is something that has important nutrients without the downsides of too much free sugar that causes these, these problems. So that is slightly harder to digest, but is full of the things that plants give you. Because remember, all carbs come from plants, not just, you know, cans of, or containers. So we're talking primarily about those that contain fibres and polyphenols. Now we've talked a lot about fibre and polyphenols and basically the less processed that food is, the more it's gonna contain those two key elements which we think are really important for our health.
Host
And can you remind us just quickly what they are and above or why they're good for our health?
Professor Tim Spector
So polyphenols are used to be called antioxidants and they are these thousands of chemicals that you find in plants, natural defense chemicals that when you eat the relatively unprocessed plant, you'll be getting the benefit of them which will go through if it's not immediately digested into your gut and your microbes will benefit from it. So they give you these really important heart benefits, anti cancer benefits, many other ones that we're just discovering. Then the other element is the fiber. So fibers are these long string of sugars that are really hard to break, break into their component parts. And most of them pass as insoluble fibers throughout our body. A few get can be mixed in with water. And the key is these reach the lower part of our colon where our microbes feed on them and they can break them down and release all the nutrients and all the goodness from those fibers which help our immune system and make our gut microbes flourish.
Host
And Tim, you were saying that when I was eating these like starchy foods, you know, I can start to, it hits my bloodstream in just sort of 30 minutes. Just as a contrast, if I'm eating these sort of less starchy foods with more fiber, how rapid is the process you're describing?
Professor Tim Spector
You probably won't see any change in your blood sugar level from having a huge bowl of some fiber rich food, or whether it's your spinach or your kale or your lentils, your beans, your nuts, whatever it is, or rye bread for example. So you won't see a sugar spike because everything's happening much slower, much lower down and it's about the speed of which these carbs are being digested. So you've got sort of fast, medium and slow. And this is really slow. And this is really what our body likes and it likes to take its time and it turns out that when you're eating these hard to digest foods, it fills you up more. So the total opposite to having those free sugars where you feel hungrier, these actually make you feel fuller, quicker, so you're less likely to eat fast, less likely to overeat. And that's part of the reason that they're helpful as well as the. Their impact on our gut and our general health. And just to put this in context, if you have 5 grams of extra fibre, which you know is actually just 1 tablespoon, 1, 1 scoop of our daily 30 mixture, for example, every day, that will reduce your risk of heart disease and early death by 14%.5 grams.
Host
Of extra fibre will reduce your risk of death by 14%.
Professor Tim Spector
Correct.
Host
I mean, it's pretty mad, isn't it? I mean, that's a lot.
Professor Tim Spector
It is. And when you think that we're supposed to be eating, you know, 30 grams of fiber, roughly, each country's got its own slightly different levels. And we're generally, most Western countries are somewhere between 15 and 20 grams is what we're actually doing. Just an extra 5 grams can make such a really big difference to your health. It's probably one of the most important things we can all do so easily.
Host
So I was thinking about your example between the two, and I was thinking a little bit about driving the car. And, you know, when you've got sort of, you know, teenage driver proving everything, they're like slamming on the accelerator and slamming on the brake, you know, when the lights change and slamming on accelerator again. And that sounds a little bit like this blood sugar spiking up and down with these starchy foods. And then I guess what I'm. I think your analogy is here is I'm eating these much more whole grain foods, a lot more fiber, and it's sort of like I'm just steady the whole time. I'm not having to accelerate or brake. And clearly if I keep doing that for 10 years, my car is going to be in much better shape than the person slamming it on and off. Is this a terrible analogy, Tim?
Professor Tim Spector
No, I think it's pretty good, actually. I think, you know, there's other things going on as well as this that are damaging your engine, but clearly your clutch is gonna go pretty quickly if, you know, you're using those gears unnecessarily. So your body is taking much more of a toll by having to deal with these glucose spikes than if you're not. That's absolutely evident. But there's also the big advantages going on in the gut microbiome of having all this food that many people are not getting in the US and the.
Host
Uk Most people I think you're describing mainly the carbs they're eating are bad carbs. So they're like, I'm not gonna eat any bread, I'm not gonna eat any french fries or potatoes or rice, you know, or crackers or pizza or pasta. Like I'm throwing it all out, I'm just not gonna eat it. What goes on inside them?
Professor Tim Spector
Well, for those people who are on a really crappy diet anyway, which is most of us, they'll feel better, okay? So that's they'll say, well I'm not because most of that food is going to be ultra processed food, low quality, low fiber. So they won't be getting the sugar spikes. They will probably feel that they've got more energy, their mood might be lifted. But after a certain while, if they're having zero carbs, they're getting zero fiber. That's going to have some knock on effects further down the line. So this is the problem we're facing with people who quite rightly want to change their diet and improve it and say, okay, you know, I'm eating too many bad carbs, let's cut them all out and let's go to say a keto or a fatty diet. They will suffer the consequences further down the road. They'll feel better initially. But if you don't look after your gut microbes, they won't look after you. And this is what we see with people who are going on a fiber free diet and some people on a fiber free diet by having carbs so as well, you can do it both ways. If you're just a really a junk food diet with, you know, like I put my son on, you know, just the McDonald's diet, there's no fiber in that. So actually you're having the similar effects. So I think it's really important for people to be mindful about what they're doing when they're cutting one group out. Okay. They should be saying, okay, let's just cut out the really, you know, the sugars, the starches, but I'm going to keep all the other good carbs in there. Then their gut microbes won't suffer and they'll be fine.
Host
And some people I think will be saying yeah, but I know that if you go on this keto diet then you know, in just a few weeks you lose all of this weight. So that must be really good for you. What would you say to them, I'd.
Professor Tim Spector
Say you will feel better if you can cope with it. Again, we've seen big differences between people on how they support a really strict keto diet. For those who don't know, a keto diet is when you're getting around 70% of your total calories as fats. So very little carbs in your diet at all and you're using fats as a fuel source. And many people can't do this. They feel sick, nauseated. Those that can support it report feeling better for definitely for a few weeks they will lose weight, but it's very hard to sustain it long term. And so that initial weight loss usually goes back to where it was. And so there's only a small percentage of people that can maintain it. And they're very vocal on social media. And I think you should realize they are a tiny minority. And keto diets do have its place for people with type 2 diabetes who are trying to get off their meds. A few weeks of that can be a good route out of your medication cycle. But as a long term solution for most people, I don't recommend it.
Host
And it sounds like the key point is you're saying you need to be eating all of this stuff that supports your gut bacteria.
Professor Tim Spector
Correct. Long term, that's what you need. That's what's going to keep you healthy, that's what will keep your immune system in place, that's going to fight the cancers, it's going to help you fight aging, all these things. So you need that armoury there. So don't give it all up for a few weeks of feeling slightly better.
Host
And Tim, we had a lot of questions from listeners about what would happen if they gave up sugar. Like how would they feel and would they feel any different?
Professor Tim Spector
Well, it all depends on where their starting point is. If they're someone who's having masses of sodas and fizzy drinks and they're having all these really starchy ultra processed foods and they decide to cut out the starch and the sugars from their diet, that means they wouldn't be getting these very large sugar spikes. Most of them will feel much better within a week of doing that because they'll be stopping these cycle of peaks and troughs. And I did this myself, interestingly, in the early days of Zoe, we had an experiment where about 10 of us took the early Zoe muffins and that's all we ate for 24 hours, every four hours, these highly sugary muffins. And my sugars were all over the place. And I felt terrible. So when I stopped doing that, I felt great. So I can understand how people, you know, would feel.
Host
And Tim, I just want to confirm this. You're saying that literally you were have doing this experiment where suddenly you were having much more sugar than you're used to. Your blood sugar was spiking up and collapsing. And literally that same day you felt terrible. So it wasn't like, oh, you're going to get diabetes in 10 years. It literally affected how you felt your energy, just like, just everything.
Professor Tim Spector
That same day, that same day I had no energy. I felt depressed. I was trying to write a chapter for my book. I couldn't concentrate. And yeah, it was a huge shock to me. And that was the first time I made this connection between your blood sugar levels and your mental state about how it's not only your risk of obesity and metabolic problems, but how it affects your brain. And that really brought it home to me. But also we did find some people that it didn't affect that much. Again, this personalized view of it. Some people are quite resistant to these sugar spikes. Others like me and you are really quite sensitive. So we will notice these big effects. But on average most people will. And I think that to me doing this experiment is, is interesting. I think so the people who are asking this question, you know, what happens if I give up sugar? As long as you understand what sugars are now and you know that bread and potatoes are also sugar, then it's worth doing an experiment just to see how you feel.
Host
And is this just because you know, you felt it yourself, or is there actually like real science to support this impact on mood and energy?
Professor Tim Spector
No, there's increasing science to show this. And in fact, our own Zoe science has shown that one of the early effects of people adhering to the Zoe program is mood and energy improving. And we believe that is due a lot to the reduction in the sugar spikes effect on the brain and the mood. It's probably a combination of, of factors, but we think that is really important. So that's come up in all our studies. Whether we're testing our prebiotic daily 30 or we're doing the Zoe program. Mood and energy changes are big. And that's been shown also in other small clinical studies.
Host
And you have to give it up completely because I heard you mention not just sugar there, but also like bread and rice. I mean, you have to give all of that up 100% in order to get the benefits you're talking about.
Professor Tim Spector
No, I don't think you need to do anything to such an extreme, unless you're just doing an experiment for say, a week for your own sake. And I think everyone should be experimenting a bit more with their, with their food to see how they react. But long term, this has got to be sustainable. And this is very much the Zoe philosophy that we want people to be on these diets for years and find out what suits them. So I still have sugar, I still have the occasional bit of honey, potato or rice, but, you know, I try and find equivalents and swaps for my staples. So I think it's about just realizing what the worst offenders are and trying to swap for something equally tasty, but. But healthier.
Host
I think actually this is a perfect time to switch over to, to listener questions. We had so many questions. I just want to pick this one out first because it seems like directly relevant, which is, Tim, what are the good carbs that you eat?
Professor Tim Spector
Well, I eat as much as I can find, so basically, you name it, I'm trying to eat it. But, you know, I, I make my own sourdough bread and I make sure it's got plenty of rye in it. And if I find some nice German rye bread, that to me is a good carb because it's very hard to digest. So it's very slow to break down that rye. I'll have pasta rather than rice. So I still occasionally have traditional wheat pasta, but increasingly switching to whole grain, whole wheat pastas, which are better for me. And then you've got all these range of grains. So things like lentils, quinoa, bulgar wheat, pearl barley instead of rice. So they're sort of little ones that people don't often think about. I certainly didn't think about those 10 years ago. So increasingly I'm making these swaps as I'm trying to move away from the.
Host
Traditional staples and whole grains and beans. I've heard you mention these are sort of the go to things, replacing the rice and the potatoes and the bread.
Professor Tim Spector
Yes. So we haven't mentioned legumes and beans, but absolutely they're a source of fats as well. So again, what's a carb source? Gives you the energy, you know, you break down the sugars slowly, but it's also got protein, it's also got fiber. So legumes are. Yeah, I, I can't get enough of those beans and lentils. And in every dish, I'm finding, as well as the classical ones, you know, we haven't talked about the spinach and the kales and the whatever. So there, there goes without saying they're in there. But I think it's about the little swaps people can make to move away from the too easy to digest ones, the ones that give you those sugar spikes.
Host
I have to say the thing that I found easiest is swapping regular pasta for whole grain pasta. And I know it's really easy because my daughter had a play date yesterday and I gave them pasta. We have whole grain pasta now in house. Gave it to her friend who's never had whole grain pasta before, I think, and she just ate it because it has cheese and whatever else and she's like, delicious. So that one is so easy to make the change. And I remember being like, really? Oh, that's a disgusting idea. And I think within a week I was like, oh, it's completely normal. So I found that very easy. Whereas I think other things are obviously harder, right. To re engineer to eat less bread, for example, you have to really rethink the sorts of food because you can't just get us, you know, if you're just always eating a sandwich, then that doesn't really work as much. And so some things are harder and some things are easier, Tim. To change.
Professor Tim Spector
Definitely, yes. I mean, so you've touched on some of them and some of these areas are new, so the foods are evolving. So you might have tried, you know, whole wheat pasta five years ago, but the new ones are actually tasting better. Similarly with the chickpea pastas or the lentil pastas, you know, they're getting better all the time, they don't fall apart like they used to.
Host
Another question, we had so much when is the best time of day day to eat carbs?
Professor Tim Spector
Great question. The literature tells us that it's the mornings that are the best time that we metabolize better. So eating an identical carb meal we have seemed to have better control over it will bring those sugar levels down quicker, digest it faster than in the evening. Now the only caveat is those studies were generally done on young people, 20 year olds and when we looked at the Zoe data, we found that really this time difference pretty much disappeared after the age of 50. So the advantages for young people may be less relevant because young people really, apart from possibly mood changes, aren't really going to suffer many metabolic changes from having these spikes. Whereas as you get older, where it's more important, there seems to be more individual differences. So some people might be early, you know, better in the morning, some people might in the evening. So I, I don't think there's a rule and I think you should follow whatever practice suits you and is likely to be sustainable. And so that's why I still have most of my carbs in the evening, because I, I know it, it doesn't affect me more than the morning and it's when I'm hungrier. So my natural body tells me to do that. So listen to your body, I think, is the rule here. And don't just because some studies have shown in young people, you know, it is better if you can eat in the morning, that's fine, but don't get obsessed with it.
Host
And you mentioned the Zoe data here. Is this a big data set that helps to inform what you're saying?
Professor Tim Spector
We've looked at thousands of people's data with Zoe who've done glucose monitors, and clearly this, this age effect and time of day is very different in young and old people.
Host
Next question.
Jonathan Wolf
Does eating carbs with other foods at.
Host
The same time affect blood sugar spikes?
Professor Tim Spector
Absolutely, yes. So what we're doing, if you eat it with other foods, you're essentially wrapping the sugars in other foods that are harder to digest. So whether they're fibers that the body can't break down or it's encased in fats is really important. So that's why the importance of thinking about food in combination, thinking about what's on your plate rather than any one ingredient is really important here. So mindful eating, realizing that if you are going to have, for example, some bread, you've got no other, you've got no healthy bread, but you're starving, well, just have it with some cheese or try and balance these things up. So that, or, you know, take it with a handful of nuts to give you some extra fiber. These have been shown quite clearly to change the height of the sugar spikes, which will then reduce the consequences. So it's not an absolute cure all for everything, but it will mitigate in a way that that sugar spike, so you can start to balance it.
Host
And do you need to sort of soak the food in that fat? So, you know, I'm thinking, because I sometimes feel like, oh, I've got that pasta, but as long as I pour loads of olive oil over it, like maybe it's going to be slower to, to break down. Does it need to be like soaked in it or can I just have the two? Like one, you know, one mouthful and one of the other. But clearly it's hitting my stomach. It's not actually sort of encased.
Professor Tim Spector
I think as long as it gets into your stomach, it will. The stomach is like a washing machine where it churns it all up. So I'm not a big fan of people saying, well, I'm going to have my fats 10 minutes before I have my carbs in order to get this, this response. I believe that generally our stomach is able to sort these things out, so if we're eating them at the same time, this should solve that problem. So I'm a bit against this obsessional eating that you have to divide your meal into 10 minute intervals. Having your cheese before you have your, and then your, your salad and then your potatoes, I think that's going a bit too far because for most purposes your stomach will treat it all the same.
Host
And does eating like a sort of refined carb with some other food, does that suddenly make it as good as eating a sort of whole grain or unrefined carb in the first place?
Professor Tim Spector
No, you can't put sprinkle on a turd. It's, it's still going to be a sugar and it's always going to be better to have those whole grains because you've got the original, original nutrients of the carbohydrate, you know, the bran, the germ, all these things on the casing that big food takes away in those foods we're talking about the good carbs, then they will still have them and you can't replace that just with a food tablets or just a bit of cheese.
Host
I have to say, my own personal experience when I was doing the first Zoe studies with you, Tim, was that I was wearing this blood sugar sensor and I ate a big pizza and obviously pizza's got lots of, of cheese on it, right, so there's lots of fat as well as this, you know, sort of bread underneath, right, which is carb. And I think I had the biggest blood sugar spike in the entire two weeks from this big pizza. It went off the roof, stayed high for so long, then finally collapsed later. And I know that I don't have very good blood sugar control, but it did definitely make me feel that I wasn't going to just be able to put a bit of cheese on like a piece of bread and magically not have any blood sugar spike. And it's a very unusual response that I had.
Professor Tim Spector
Well, everyone's different, but there's plenty of people like you and we all respond differently to fats and sugars as we know. But I think it's a mistake to think that you can have unhealthy carbs like a massive pizza base and Just smother it with all kinds of unhealthy fats and which might mask that sugar spike. But remember the fats. This is another podcast, but, you know, at six hours, your, your body's still trying to get rid of those fats in your body and can cause more problems than the sugar. So let's not swap one problem for another. You know, pizzas are fine. Have them every now and again. Enjoy it as a, as a treat. You know, maybe have your salad as your starter, which does help prime your. Your blood sugar. But don't get too crazy on the extra fats.
Host
I think one of the things that this has done is just change my mind to think about a lot of these things more like treats than as just sort of the, oh, you must eat this, because this is your source of energy and you need to, you know, if you're not eating lots of bread before you go out in the morning, then, you know, how could you possibly function in the day? But another question that came up surprisingly.
Jonathan Wolf
Often, does freezing your bread make it healthier?
Professor Tim Spector
Great question. And this is this whole question of what's called resistant starch. So bread is a good example, but it could be, the question could be also be for pasta, could also be for rice. And it comes from these studies that showed that if you cook these products and then the next day you put them in the fridge, then you reheat them, that they could be healthier because in some way the starch, the sugars have become more resistant to digestion. That's why they're called resistant starches. And so they actually became more like fiber. About 10 years ago, when I first looked at it, this was more theoretical than real. But the last few years, there have been a number of studies now showing quite consistently that you get a benefit on the amount of sugar that comes out of that food. And the sugar spikes if you do this for rice, for wheat, for pastas. And I was very skeptical, but now I think actually it's quite reasonable. I'm not sure that I'd always want to be cooking everything two days in advance and leave it in the fridge, but it's sort of an extra reason to have those leftovers and do batch cooking for many people, because it will slightly improve how much, you know, goes down to your gut and how much less. Less is released. So, yeah, whether it long term, it's a technique, I don't know, but it's quite a fun thing to think about.
Host
I am thinking about bread, which my experience always, when I've Frozen and taken it out afterwards is it never tastes half as good as the bread before it went in the freezer. So I can believe that it's been changed. But it seems like quite a hard hit on the taste in order to reduce your blood sugar a little.
Professor Tim Spector
Yeah, no, I think bread's a tricky one. I mean, and you may need to remember to maybe want to slice it first before you freeze it as well. But I do freeze my sourdough. Interestingly, it still tastes good. Some studies have shown that actually blind tasting pasta and rice, people report it tastes better on these blind experiments. So perhaps it does change some other attributes of those foods that. But, you know, often my takeaway tastes better the next day. I mean, I think that's most people.
Host
I think the pasta I definitely have often reheated and very happy with it. Was the bread somehow I do feel the bread out of freezer wine taste. I think I could tell the difference.
Professor Tim Spector
Yeah, it may depend on the quality of the breads, but, you know, extremely high fibre ones, it's probably fine. But the other ones. Yeah, I agree, they don't taste as good to me either.
Host
Well, I've definitely never baked my own sourdough bread at home, Tim, so I'm not in your league. But I aspire to it. I think you already touched on this question, actually, which is about other starches. So what are the other sort of starchy foods other than bread that this could help with?
Professor Tim Spector
The ones that have been tested are things like rice and pasta. And it's a good thing really, if you do batch cooking, particularly if you are still keen on rice and we're not particularly keen on white rice at Zoe, but realize that some people are. The reheated version will perhaps give you 30% less of a sugar spike compared to the fresh one. And it probably works for most of these types of foods that are staples, but in general, interesting. Black rice, wild rice isn't much better. Brown rice isn't much better than white rice. That's a common misconception, really. Doesn't have that much fiber in it or that much extra protein. So by all means, go stick with white rice if you like it, but just maybe cut down the quantities and how often you have it.
Jonathan Wolf
Do you know someone who's confused about carbs? Maybe they struggle with an afternoon slump and they don't know why. Why not share this episode with them right now and equip them with expert advice on what foods could fuel them better? I'm sure they'll thank you, Tim. If A food item has a multigrain label.
Host
Does that mean it's a healthy carb?
Professor Tim Spector
Sadly not, no.
Host
That's disappointing.
Professor Tim Spector
It is. They mean nothing. It's just a marketing technique. There are only a few terms that have any legal requirement for manufacturers to contain things, and these are whole wheat and whole grain, which are used differently in the US and the UK and Europe. So those ones mean that you do have to have the grain intact, that they can't have stripped away the germ and the bran, and that you know, you're getting something that's, that's higher in fiber. Percentages vary, so they, they're always trying to get away with as little as possible because it's, it's more expensive to do this and it doesn't have a long shelf life. Things like this that big food doesn't like. But multigrain, multi cereal means absolutely nothing. So usually they've got a few sesame seeds on top and you think that bread looks healthy, but actually it's not. And this goes across all foods. Ignore those signs, really. Look at the back of the pack, look to see how much fiber is actually in it, how many grams of fiber, and it's per hundred. So it's percentage fiber you'll be getting when you look at the back of those labels.
Host
And so what's the number that you would be looking at for fiber that would help to tell you this has moved to being like a good carb instead of one of these sort of refined bad carbs we've been talking about today.
Professor Tim Spector
If you're getting like 5 grams of fiber per hundred grams, or sort of 5%, that's sort of a minimum to be looking at. But again, it's complicated because some foods you need to be looking at the ratio of the fiber to the starches. And bread's a good example of that. You can have reasonable amount of fiber, but if you've got 10 times as much sugars in it, it's not going to work. So I think it's not as straightforward as that. So start by looking at the fiber, but also say we'll look at the carbohydrate total and you know, a good bread will be something like a ratio of only 4 or 5 to 1 of carbs to fiber. But most common breads are about 20 to 1.
Host
Got it. So mainly like breads, rice, potatoes are going to have a lot less than that 5 grams that you're talking about.
Professor Tim Spector
Yes, much less.
Host
So if I am looking for a bread, you're saying like multigrain just means they might have dropped a couple of other grains on top of it. So what is it that I am looking for to try and make me know that it is like a higher quality bread?
Professor Tim Spector
Yes. So multi grain, multi cereal, stone ground mean nothing. They can just, they can have 1% of it in that form and that's enough.
Host
Which is completely shocking.
Professor Tim Spector
Yes, it's ridiculous. There's no real good regulations in the US or in Europe about things like bread. But what you can look for is in the us, whole wheat means it has to legally contain the whole, the kernel, the bran, the germ of that wheat husk in that product and there's a certain minimum amount they have to have in it. And the UK is generally only called whole meal. And apart from that, really, it's the Wild West. And you, you know, the key is to look on the, the back of the pack and see what the amount of fiber is and the amount of carbs are.
Host
So if it has those other parts that you mentioned, that's going to be healthier for me generally.
Professor Tim Spector
Yes. If you've got the whole part of the cereal in it, then it will be much healthier for you. They don't have to have any additives to it because what they're doing is when they're in these cereals, generally they're stripping away all the good stuff and they have to then put it back in as chemical vitamins and so that will be called.
Host
You said whole meal or so in.
Professor Tim Spector
The UK the term is whole meal has a legal requirement and in the us, whole wheat and everything else really is just marketing and they can contain just small amounts of that and the basic product is unhealthy. And this was very interesting. And, you know, I gone through this big journey because anyone who goes to a supermarket surrounded by these labels and healthy looking things with seeds and Maltese seeds and stone ground, this and whatever, but it's, and sadly it's all pretty meaningless.
Host
So, Tim, if you are buying bread in the supermarket, how do you choose a good bread?
Professor Tim Spector
I generally disregard the labels. Look on the back of pack, see, go for the one with the fewest ingredients and the highest ratio of fibres to carbohydrates.
Host
Brilliant. Thank you. And that takes me on to another question from people who obviously are making things at home, because we had a lot of questions about flour and lots of questions about whether alternative flours. We had quinoa flour, chickpea flour, almond flour, amongst others. Is that better than the traditional wheat flour, which, you know, I Remember growing up and you know, my grandmother would use to, to bake something with.
Professor Tim Spector
It depends. It sort of depends what you're using it for. Some of these ones will contain different ratios, so you might get more protein, for example, if you're, you're taking some from a legume, like a chickpea. So it depends what you're trying to achieve in reversing it. So I don't think we should move away from wheat flour necessarily, but you want to be picking ones that are, you know, the whole flour. So these are the ones where you don't want it to be ultra refined. So it's more the amount of refinement that is important here, how much of that whole plant is still in that food. But I think increasingly using a diversity of different flowers is fine, but the more refined it is, the more chopped up it is, the, the least beneficial it's going to be for your health. And I think that that's in general. So the, the cruder, more unrefined all of these are, I think, the better.
Host
So you definitely prefer that I was using not like the white flour that I grew up with, but like whole wheat flour or wholemeal flour that has like all of the, the grain of that wheat in it. Even if. Is that, is that what you're saying?
Professor Tim Spector
That's right. So that might be better than some of these refined alternative flours that, you know, still worth experimenting with for different purposes. But, you know, there's been this big anti gluten campaign and that's why sort of wheat got a bad name. But I think we should be focusing on, again, the quality of those ones and going for the ones that do have, you know, the higher fiber, higher protein counts within them and then go for taste and what you fancy eating. But I don't think we should give it all up just because, you know, of a particular, you know, worry about glutens in 1% of the population.
Host
So you're not saying, therefore that in general people should give up, up all wheat. You're saying, if I think I understand rightly, it's like the refinement of that where you throw away a lot of the comments, you're just getting left with sort of the starchy, sugary bit, which is the white flour, which I have to say, I love in my croissant. Pain au chocolat does taste nice, but you're saying it tastes nice because it's really sugary.
Professor Tim Spector
Yes, exactly. That's right. You're just getting that, you know, flavor bomb of Sugar. Whereas, you know, if you're making pancake, do you ever make pancakes?
Host
Yes.
Professor Tim Spector
So if you swapped for buckwheat flour or spelt, you'd be getting much less of the sugar, more of the fiber. So in many instances there are swaps. People can make that. You can, but generally you're swapping for something that is a higher density, more protein.
Host
And does it, can it still taste nice?
Professor Tim Spector
The buckwheat pancake definitely can, yes. I love them.
Host
All right, we'll put the link to that in the show notes because I'm going to give that a try. That is just about within my culinary capability is a pancake. That's sort of the limit, Tim. So my kids expect pancakes from me from time to time. At the weekend. I'd like to finish with a final question, which I loved because it was so straightforward. Julie wrote into us and said, if.
Jonathan Wolf
I want to improve my carb intake.
Host
Tomorrow, what's the easiest way to start?
Professor Tim Spector
Well, it depends what you're calling a carb. We're going back to our original question. So if you want to improve your good carb intake, which means the ones towards the more fiber elements, it would be to swap your more starchy, more sugary carbs for the ones that have more fiber in it. And we've been discussing a lot of these and it's simple swap. So go with the staples. Look at your staples of your. Can you change your bread for something that's, that's, that's healthier? Can you change your pasta to a whole wheat pasta? Can you change your white rice to a quinoa pearl barley? Something that's really high in fiber and prime protein. So it's looking at those, those ones that make up the majority of what we're eating, plus reducing those carb snacks. So instead of your savory snacks, your Doritos, your Pringles, you, you have some nuts and seeds instead that, that's. If you want a simple start starter, that's what I would do. And I think it's. The staples are the ones that are the main ones. So for most people, changing their bread is probably the hardest thing they can do. So try and focus on that and find a loaf that's healthier that you enjoy.
Host
Thank you, Tim. I think that's really clear. It's been a bit of a whistle stop tour across, like, a lot of ground today. I'm hoping we've answered a lot of questions for our listeners. I'm gonna try and do a quick summary, maybe just of the highlights that I took away from today. So I think I start with your blood sugar spikes. Like if you suddenly started spiking your blood sugar, it could actually affect your mood and energy in one day. Which is really amazing because I was brought up with this idea that you know, how you feel and what you're eating have nothing to do with each other. And so I think that is really remarkable and it's been one of, I think really eye opening idea that you could have that impact that fast. I also am thinking about the Pringles designed so that once you pop, you just can't stop and that this is real and you're describing the ways in which you could see what's going on in your blood sugar that is actually happening to create this craving and make you want to continue. I think you then shocked, you know, definitely some of our listeners by saying that, you know, rice basically gets turned into sugar almost immediately and isn't healthy. Despite all the ways that I think both of us were brought up to believe that it was. And that actually, you know, potatoes and bread are very similar. They sort of high starchy food, they're getting turned into sugar very fast inside your body. But don't therefore be scared of carbs and suddenly say, well, I'm just not going to have any carbs. I'm just going to eat lots of fat and protein because you said it's essential because it is all coming from plants and it's the food that feeds, you know, our gut microbes, those bacteria. And you shared, I think the most amazing statistic. You said if I was to add 5 grams more fiber into my diet, I would reduce my risk of death by 14%. So it's a very small amount of fiber. It's like one teaspoon or something and like this huge impact on death compared to everything else we talk about. So that is remarkable.
Jonathan Wolf
And then I think you switched a.
Host
Whole bunch of tips. Freeze your bread, put your pasta or your rice in the fridge and then take it out again and suddenly it's going to have lower sugar spikes. Re examine what, what you're buying from the supermarket. You talked about breads and said like a lot of the labels are just tricks. You know, this is sort of big food taking advantage of you. There's incredibly little regulation, you know, around the world. Whether you're listening to this in the US or the uk, Europe, wherever. And what you're looking for is a sort of whole wheat or whole meal that has the whole kernel back to this idea of it Being like the whole grain rather than just a bit that's refined. And if you see something like multigrain, which I always thought was, that's great, I've got all of these grains, actually, you're just being tricked. So for you, you're saying, really, you need to turn the bread over, look at what's on the back. And you're looking for as few ingredients as possible and you're looking for the amount of fiber. And in general, I think you said, you know, fiber is above 5 grams in any of these foods, it's starting to be meaningful. That's like an easy indicator of this being a sort of a good carb rather than, than a bad carb.
Professor Tim Spector
And the ratio. Yeah, and the ratio, the ratios. You've got to look at the carbs because sometimes you can have fiber, but they've put in so much sugar in there that it. So it's that ratio of the total carbs to total fiber.
Host
Got it. Because you say it might have 5 grams of fiber, but it's got tons of like 80 grams of carbohydrate and some sugar. It's still not gonna be good for you. Got it. So you've got to watch out again for, for how they played with this. And then finally you said, jonathan, try swapping out those pancakes, stop using the refined white flour and in fact try something different from wheat. Try a buckwheat flour or a spelt pancake. And I promise to try this and I will report back.
Professor Tim Spector
Fantastic.
Host
Tim, thank you so much. I appreciate it and I am sure we will continue the journey.
Professor Tim Spector
Thank you.
Jonathan Wolf
Now, if you listen to the show regularly, you already believe that changing how you eat can transform your health. But you can only do so much with general advice from a weekly podcast. If you want to feel much better now and be on the path to live many more healthy years, you need something more. And that's why more than 100,000 members trust Zoe each day to help them make the smartest food choices. Combining our world leading science with your Zoe test results, Zoe is your daily companion to better health for life. So how does it work? Zoe membership starts with at home testing to understand your unique body. Then Zoe's app is your health coach. Using weekly check ins and daily guidance to help you shift your food choices to steadily improve your health. I rely on Zoe's advice every day and truly it has transformed how I feel. Will you give Zoe a try? The first step is easy. Take our free quiz to find out what Zoe membership could do for you. Simply go to Zoe.com podcast where as a podcast listener, you'll get 10% off. As always, I'm your host, Jonathan Wolf. Zoe Science and Nutrition is produced by Julie Pinero, Sam Durham, and Richard Willan. The Zoe Science and Nutrition Podcast is not medical advice, and if you have any medical concerns, please consult your doctor.
Host
See you next time. Sa.
ZOE Science & Nutrition Podcast Summary
Episode: The truth about low carb diets, sugar spikes, and ‘multigrain’ labels | Prof. Tim Spector
Release Date: March 27, 2025
Host: Jonathan Wolf
Guest: Professor Tim Spector
In this enlightening episode of ZOE Science & Nutrition, host Jonathan Wolf engages with renowned scientist Professor Tim Spector to demystify the complexities surrounding carbohydrates, their impact on health, and the often-misleading marketing tactics employed by the food industry. Drawing from Tim’s extensive research and his own personal experiments, the discussion offers practical advice for listeners aiming to make informed dietary choices.
Defining Carbs:
Professor Spector begins by clarifying that carbohydrates (carbs) are one of the three primary macronutrients, alongside proteins and fats. He emphasizes that rather than consuming "carbs" in isolation, individuals typically consume plants containing varying amounts of proteins, fats, and different types of carbs.
Types of Carbohydrates:
Carbs are categorized based on their chemical complexity:
Simple Carbohydrates:
Example: Table sugar (sucrose), honey, and high-fructose corn syrup. These have few bonds and are quickly broken down by the body, leading to rapid energy release.
Quote:
"[...] simple sugars like sucrose... means you don’t actually eat a carb, you eat a plant."
[01:28] – Professor Tim Spector
Starches:
Example: White rice, pasta, potatoes. These are more complex than simple sugars and take slightly longer to break down, initially being processed by saliva enzymes in the mouth.
Quote:
"[...] starchy carbs which are transformed fairly rapidly into sugars, gives you a sugar spike in your blood."
[07:41] – Professor Tim Spector
Complex Carbohydrates (Fibers):
These are long chains of sugars that are hard for the body to break down, often passing through the digestive system and feeding gut microbes instead.
Blood Sugar Spikes:
Spector explains how consuming simple and starchy carbs leads to rapid increases in blood glucose levels, triggering insulin production to lower blood sugar. Repeated spikes can strain the body, leading to metabolic issues and increased hunger.
Quote:
"After about 30 minutes, a sugar spike in your blood... triggers production of insulin... causing effort to the body."
[08:45] – Professor Tim Spector
Personal Experiment:
Tim recounts an experiment where consuming high-sugar muffins resulted in significant blood sugar fluctuations and negative mood and energy levels within a single day.
Quote:
"I have no energy. I felt depressed... and couldn’t concentrate."
[31:12] – Professor Tim Spector
Hunger and Cravings:
Rapid sugar spikes can lead to a subsequent dip in blood sugar, increasing feelings of hunger and promoting overeating. This cycle contributes to weight gain and difficulty in maintaining a healthy weight.
Quote:
"What does it do? Gives you a sugar spike, Maybe you get a dip... you're eating more during the rest of the day."
[10:49] – Jonathan Wolf
Obesity Epidemic:
Shifting dietary guidelines from fats to carbs and sugars has been linked to the rise in obesity and related metabolic diseases over the past decades.
Quote:
"As we shifted away from fats to carbs and sugars... we've been seeing increase in obesity in heart disease."
[12:58] – Professor Tim Spector
Marketing Tactics:
The food industry promotes cheap, starchy, and sugary products to maximize profits, often at the expense of consumer health. Products like Pringles are highlighted as examples of foods engineered to be addictive.
Quote:
"...Pringles are made up of about four different plant extracts... glue them back together to look like a potato."
[18:03] – Professor Tim Spector
Addictive Properties:
Combination of carbs with fats and salt creates a "bliss point," making snacks highly addictive and hard to stop consuming.
Quote:
"These combine the carb with salt and some fats as well... your brain just lights up with dopamine."
[19:26] – Professor Tim Spector
Characteristics of Good Carbs:
Good carbohydrates are those high in fiber and polyphenols, which provide essential nutrients without causing significant blood sugar spikes.
Example Foods:
Quote:
"A good carb is something that has important nutrients without the downsides of too much free sugar... contain fibers and polyphenols."
[20:18] – Professor Tim Spector
Benefits of Fiber and Polyphenols:
Fibers aid in digestion and support gut microbiota, while polyphenols offer antioxidant properties that contribute to heart health and cancer prevention.
Quote:
"5 grams of extra fiber... will reduce your risk of heart disease and early death by 14%."
[23:59] – Professor Tim Spector
Swapping Sugary to Whole Grains:
Professor Spector advises replacing refined carbs with whole grains and fiber-rich alternatives to stabilize blood sugar and promote satiety.
Practical Tips:
Quote:
"Swapping white to whole grains, beans, etc. is essential for maintaining gut health and preventing sugar spikes."
[35:35] – Professor Tim Spector
Reducing Processed Carbs:
Limiting consumption of ultra-processed starchy snacks like chips and crackers is crucial for reducing unnecessary sugar intake and managing hunger.
1. Freezing Bread to Reduce Sugar Spikes:
Freezing cooked carbs like bread, rice, or pasta and then reheating them can increase resistant starch, making them slower to digest and causing lower blood sugar spikes.
Quote:
"Reheating them gives you a benefit on the amount of sugar that comes out of that food."
[46:07] – Professor Tim Spector
Practical Consideration:
While beneficial, this method may alter the taste and texture of certain foods, such as bread.
2. Best Time of Day to Eat Carbs:
Morning consumption of carbs may lead to better blood sugar control, especially in younger individuals. However, this advantage diminishes with age, and timing should be personalized based on individual responses.
Quote:
"The literature tells us that it's the mornings that are the best time that we metabolize better... but after the age of 50, the advantage pretty much disappears."
[37:37] – Professor Tim Spector
3. Multigrain Labels and Healthy Carbs:
Multigrain labels are largely marketing tactics with no substantial meaning regarding nutritional quality. Instead, focus on the fiber content and the ratio of fiber to total carbohydrates.
Quote:
"Multigrain, multi cereal means absolutely nothing... look at the back of the pack, see, go for the one with the fewest ingredients and the highest ratio of fibres to carbohydrates."
[48:53] & [53:48] – Professor Tim Spector
4. Choosing Quality Bread:
When selecting bread, disregard front labels like "multigrain" or "stone ground." Instead, prioritize products with fewer ingredients, high fiber content, and whole grain integrity.
Quote:
"Look on the back of pack, see, go for the one with the fewest ingredients and the highest ratio of fibres to carbohydrates."
[53:48] – Professor Tim Spector
Jonathan Wolf summarizes the critical insights from the episode:
Blood Sugar Awareness: Eating starchy carbs can cause immediate and noticeable changes in mood and energy due to sugar spikes and crashes.
Addictive Carbs: Processed carb-rich foods like Pringles are engineered to be addictive, fostering overeating and health issues.
Debunking Myths: Common staples like rice and potatoes, once considered healthy, can lead to rapid blood sugar increases similar to sugary foods.
Balanced Approach: Eliminating all carbs isn't advisable. Instead, focus on consuming high-fiber, nutrient-dense carbohydrates to support gut health and overall well-being.
Fiber’s Impact: Adding even a small amount of fiber to the diet can significantly reduce health risks, emphasizing the importance of fiber-rich foods.
Smart Swapping: Simple dietary changes, such as swapping white pasta for whole grain or using alternative flours, can enhance carbohydrate quality without sacrificing taste.
Final Quote:
"Swap your more starchy, more sugary carbs for the ones that have more fiber in it... look on your plate rather than any one ingredient."
[58:56] – Professor Tim Spector
By implementing these strategies, listeners can make informed dietary choices that promote sustained energy levels, better mood regulation, and long-term health benefits.