Nutritioninterview

FORGET WHAT YOU EAT, IT'S WHEN YOU EAT THAT CHANGES EVERYTHING | DR BERRY

with Dr Berry

42:49·12 February 2024

LISTEN NOW

Listen on

DR BERRY

Sarah Berry is one of the most-cited nutrition researchers working today — Professor of Nutritional Sciences at King's College London and Chief Scientist at ZOE, where she leads the PREDICT studies into how the same meal produces 20-fold different glucose, lipid, and inflammatory responses across individuals. For cyclists chasing the last 2–3% of body composition, fixing mid-ride GI issues, or trying to make sense of why a sports nutrition plan that worked for a teammate doesn't work for them, her work is the most rigorous starting point.

Verified profiles

zoe.com kcl.ac.uk

KEY TAKEAWAYS

Individual blood glucose responses to identical meals vary up to 20-fold between people. Generic nutrition guidelines underperform personalised approaches because the variation is genuinely enormous.
Ultra-processed food gets eaten 50% faster — bypassing satiety signals — and produces ~500 extra calories per day at the population level. The mechanism is consumption speed, not just composition.
Eat fibre, fat or protein BEFORE carbohydrates. Same meal, lower glucose peak. Slows gastric emptying. Free intervention, food order doesn't change food content.
Sleep deprivation worsens metabolic response to identical food. Same breakfast after a bad night = higher glucose peak. Prioritise sleep as a direct nutritional strategy.
Evening snacking after 9pm is structurally bad — circadian disruption + worse food choices. The same calories earlier in the day land differently.

TOPICS

Dr Sarah Berry breaks down why the timing and context of when you eat matters just as much as what you eat. From blood sugar spikes to sleep deprivation cravings, discover how your daily habits shape your metabolic response to food—and why there's no one-size-fits-all nutrition approach.

Key Takeaways

Individual responses to food can vary by up to 20-fold—what works for one person's metabolism may be completely different for yours, making personalized nutrition crucial
Eating ultra-processed foods causes you to consume ~500 more calories daily and eat 50% faster, bypassing your fullness signals before your brain registers satiety
Sleep quality directly impacts blood glucose response: a poor night's sleep creates higher blood sugar peaks and increased cravings for refined carbs, even when eating identical meals
Meal ordering matters—eating fiber, fat, or protein before carbohydrates slows glucose absorption and prevents harmful blood sugar spikes
Evening snacking after 9pm is particularly problematic due to circadian rhythm disruption; most people also choose less healthy snacks later in the day
Food diversity optimizes health by exposing your body to thousands of beneficial plant chemicals (polyphenols) and feeding diverse gut bacteria—but adequate fiber and reduced ultra-processed foods are the foundation

Expert Quotes

"I think having spent 25 years in nutrition research where I always focused on what we call the average response...suddenly delving into how individuals respond differently has been a real eye opener in terms of the size of the difference—you can see like a 20-fold difference in how you might respond to a food versus how I might respond."

"The problem is that people do need simple messaging but also people want quick fixes when it comes to nutrition...there isn't a silver bullet it's not that simple. Food is complicated, how we respond is complicated."

"If a food is too healthy to be enjoyed it's just not healthy at all...food should be there for joy as well as to be healthy."

CLAIMS FROM THIS EPISODE

Each tagged with the strength of evidence behind it.

STUDY
ZOE research, summarised by Dr Sarah Berry, shows individual blood glucose responses to identical meals can vary up to approximately 20-fold between people — driven by gut microbiome composition, genetics and metabolic health.
Source: Dr Sarah Berry, ZOE personalised nutrition research, on the Roadman Cycling podcast
STUDY
In trials comparing ultra-processed and nutritionally-matched whole foods, participants ate ultra-processed meals about 50% faster and consumed approximately 500 extra calories per day, with measurable weight gain within a couple of weeks.
Source: Ultra-processed food research summarised by Dr Sarah Berry on the Roadman Cycling podcast
STUDY
Eating fat, protein or fibre before carbohydrate during a meal slows gastric emptying and meaningfully blunts the glucose peak that follows — no change in food content required.
Source: Glycaemic-response research, summarised by Dr Sarah Berry on the Roadman Cycling podcast
STUDY
A poor night's sleep worsens insulin sensitivity and amplifies blood glucose response to identical food the following day — sleep functions as a direct nutritional input, not just a recovery input.
Source: Sleep and metabolic-response research, summarised by Dr Sarah Berry on the Roadman Cycling podcast

KEY QUOTES

“we know from research that if you eat heavily processed so Ultra processed food compared to nutritionally matched food but that just hasn't been through all these levels of process you on average consume 500 calories more per day”
Dr Berry — Nutrition researcher at ZOE

“those that were fed the ultra processed food they ate the food 50% more quickly so they hadn't had time for the fullness signals to say hey stop you know you don't need to eat anymore they ate 500 calories more each day and within just a couple of weeks they started to put weight on as well as it impact their metabolic Health”
Dr Berry — Nutrition researcher at ZOE

“if you have a good night sleep and you have exactly the same breakfast compared to if you have a bad night sleep and have exactly the same breakfast you will have a lower blood glucose response”
Dr Berry — Nutrition researcher at ZOE

EPISODE TRANSCRIPT2 SECTIONS

How Individuals Respond Differently to Food

Dr Sarah bur welcome to the robman podcast thank you for having me Anthony Sarah you've worked a lot in the area of personalized nutrition what's been the most surprising findings that you found about how individuals can affect their responses to various Foods so I think having spent 25 years in nutrition research where I always focused on what we call the average response so looking at how a group of individuals respond to one kind of diet versus another kind of diet I think over the last six years suddenly delving into how individuals respond differently has being a real eye opener in terms of the size of the difference I had never really considered just how huge the difference is between how I might respond to a food versus how you might respond to a food and depending on what outcome we're looking at you can see like a 20-fold difference in how you might respond from some particular Health measure to a food versus how I might respond it's really interesting because I've long looked at these peer-reviewed studies on on food and I look at it and it say you know a group of 200 people you know went through this protocol and they responded in this way and I always find myself walking away from a con I don't really care how the 200 people responded I care how I respond to this same protocol yeah and I think you know it for populationbased guidance then the average response or the mean response is really valuable so for um population based guidance saying okay on average should we be giving people more fiber should we be reducing people's saturated fat intake then those kind of studies looking at the average where everyone responds generally in the same direction for example saturated fat is bad for everyone fiber is good for everyone then looking at the average response is really valuable but food is so much more nuan than all of the these nutrients uh that are in it we know that food has thousands of chemicals and these thousands of chemicals are packaged within a very complex food structure which we call Food Matrix and if we combine that complexity of food together with the complexity of us that's why we respond so so differently in different directions and this is where it's really important like you say not to think about how everyone else responds or how the average person responds but how you as an individual respond have you looked studies about the nonbiological response of food like by that I mean food is such a ritualistic thing for us and it has been since you know we were cavemen that we celebrated by sitting around the fire and cooking meat together and there's still something about that most of us get together at the holidays or if you're the states around Thanksgiving the family all comes together so food has a purpose that's greater than just the chemical reactions that take place when we eat it has that been studied much so I when I think about our health responses to food or when I think about how we should personalize advice around food um I think about it across four different areas so I think about it in terms of what we eat and by what we eat I think Beyond Simple nutrients like fat protein fiber carbohydrate but you know all of the thousands of nutrients in The Matrix I think about who we are and by who we are I mean our biology so whether it be our microbiome or our genetics or our age our sex I think about how we eat and by how we eat I mean like what time of day we're eating the meal ordering are we having carbohydrates in the morning or the afternoon how long have we fasted overnight when have we done Exercise what was the intensity duration and timing of that exercise compared to our meal and then I think about why why do we make those dietary choices is it cultural is it simply because we're hungry and we like the food is it emotional and I think an area that hasn't been researched enough but it's an area I'm really excited by is the how we eat and that's really personalized as well so the um who you are like your biology that I mentioned shapes a lot of how you respond to food but the how you eat is another huge area of personalization that we're really starting to discover more and more particularly the research that I'm doing at zo around things like eating rate time restricted eating timing of eating physical activity Etc sleep as well you mentioned meal ordering is this a case of like you know we have chairs around the table in Titanic and no matter what order we put these in it's essentially going to be the same outcome but meal ordering is this idea that you can arrange these chairs differently and we get a different outcome yeah absolutely um I think it's a perfect example of the complexity of what shapes our responses to food because there's so many thousands of different variables each day that are going to partly shap how you respond to that food and so when we talk about meal ordering we can look at it in two different ways one is simply how does what you have for breakfast impact your response to your lunch meal and how does the order of the food that you eat within that same kind of sitting impact your response so if we think about circulating blood glucose which is a measure of blood sugar so when you have any foods containing carbohydrates you have an increase in circulating blood glucose and I'm sure uh many of the cyclists listening here will be well aware about the importance of maintaining a certain level of circulating blood glucose and what happens is is when you eat a carbohydrate Rich meal you have an increase in blood glucose that Peaks around 15 minutes returns to Baseline around 30 to 45 minutes after eating that carbohydrate now if that Peak is excessive like really really high and if you also have what we call a blood sugar crash so a dip we know that the excessive Peak if it's repeated time and time again is bad for the health so we know it increases inflammation it increases type 2 diabetes risk it increases your chance of getting obesity and cardiovascular disease we also know that the dip is problematic in terms of alertness energy um and also calorie intake at subsequent meals so something that we focus a lot of our research on is looking at how we can modify the shape of that glucose curve after you consume carbohydrates so how you can prevent the really big Peaks that are harmful to health or prevent the big dips that we know are unfavorable in terms of those other factors about how you feel and the this really nicely can illustrate as well the importance of meal ordering so for example we've conducted a study at zi where everyone had in random order different breakfasts so we had 50 people who over a couple of week period um in random order Had Each morning after fasting overnight a different kind of carbohydrate Rich breakfast but everyone had exactly the the same lunch meal now their blood glucose response after their lunch meal was partly shaped by what they had for breakfast and so even though they're having exactly the same lunch meal what we also see within a meal and this is quite a new area of research that the order in which you eat your Foods within a meal can also impact your blood glucose interesting and so we know that fiber in a meal fat in a meal and protein in a meal delays your rate of gastric empting so it delays the rate at which your stomach empties and therefore the rate at which the blood glucose will appear in your bloodstream so if for health reasons you want to reduce that sudden peak in glucose then it's really good to have before your carbohydrates or with your carbohydrates um fat protein or Fiber so you could have some uh if you're having let's say you're having a stter or you're having a kind of little snack before your made meal if you had something that contained fat protein or Fiber it would delay the rate which your stomach empty that glucose into your bloodstream now I know that it's different in in Sports Nutrition that sometimes you want that rapid increase in blood glucose in which case that's why you're best to have just um something that contains glucose or sugar so you're not delaying the rate at which empty so that you can get that rapid uh rise into your bloodstream I think people feel so overwhelmed about nutrition Sarah and it's because it's so complex and I spoke to Dr Dan PL on the podcast he's an expert in heart rate variability and he said one of the challenges with heart rate variability is there's a lot of academic research on heart rate variability and it's an extremely complex topic but then what you're trying to do is take something that is in its Essence very very complex and to try and simplify it for a mass audience so you're trying to take a measurement of heart rate variability and bring it into a whoop or an aura ring and simplify it as one number to say okay I feel good today I feel bad today when the reality of it is heart rate variability is a lot more complex than just looking at a number and saying I feel good I feel bad as whoop or Ora would try and have us believe nutrition kind of feels the same to me that the mass media wants to simplify it if you do X you're going to be healthy when it is a very nuanced and multifaceted area of discussion yeah absolutely look everyone wants a silver bullet everyone wants a quick fix and you know nutrition Health exercise it you know it's all the same it's so nuanced um and all of these different metrics like you say you know that I have an aura ring myself and I actually don't look at the combined scores like I think it gives a readed a score I wouldn't look at that now that's partly because I'm a scientist and I know that it's oversimplifying it and actually for me is I believe is quite meaningless the problem is is that people do need simple messaging but also people want quick fixes when it comes to nutrition and so this is why you see this rapid growth that we're having recently and things like these green powders you know the juices that people are having and they're like oh well you know I can eat what I want this is in a food landscape where 60% of our energy is coming from ultra-processed food that we know is bad forast but hey that's fine I'll just add in one of these green powders or shakes and it offsets it unfortunately it's not that simp Le and you know I have a boring message because it there isn't a silver bullet it's not that simple food is complicated how we respond is complicated now we can make it simple by following some very simple principles in terms of reducing how much alra press food we have in terms of listening to our hunger signals trying to eat a plant diversity so trying to eat more plant-based Foods in their original structure unprocessed But A diversity of different plants trying to in our fiber intake trying to add fermented food in as well um so there's lots of simple uh strategies we can incorporate but Within These it's nuanced and you know perfect example if I I can give you an example of sometimes why it can be so confusing is dairy now for years and years people have been told you've got high cholesterol reduce your Dairy intake don't have loads of cheese dair's got loads of saturated fat in saturated Fat's bad for us but what we know is that actually it's not that simple So within the category of dairy you've got hundreds of different products different cheeses different yogurts butter milk Etc what we know is that if you ferment Dairy which is what happens with cheese and which is what happens with with yogurt that it changes the structure so whilst it still has loads of saturated fat in it the process of fermentation that changes the structure actually prevents the normal increase in cholesterol that you would see from having the unfermented butter or milk for example and so therefore a headline saying reduce your Dairy if you've got high cholesterol actually is oversimplified because it's fine to have cheese it's fine to have unsweetened yogurt if you have uh because it won't increase your cholesterol intake uh your cholesterol levels well I know in sports I see people and I call it major things where they have too much focus on Stu that is marginal in the benefit for them and not enough focus on the unglamorous reality of you need to sweat and you need to train quite a lot to get any adaptation and I wonder is the same true of nutrition we be preparing for this podcast I sat in the cafe across the road and I just observed people G past and anecdotally like I would say 70 to 80% of people that come into the C Cafe are overweight and I wonder is there like a maslo hierarchy needs equivalent with nutrition where if we're faced with this obesity epidemic where you're talking to people about ferment and cheeses you know is the reality they need to be looking at macro control and they need to be looking at you know getting a caloric neutrality or deficit each day and maybe forgetting about the fermented cheeses is does that type of thinking exist within the nutritional sphere yeah certainly amongst nutritional scientists like myself we are always conscious of what we call the size impact so in the same way that you talk about the major and the minor we talk about what is the size impact of making that change in terms of a given Health outcome now some of the um areas that are heavily promoted now particularly amongst influencers um and they kind of seen as you know sexy changes to your diet actually have quite a small size size impact yeah now for some people even starting small if it helps them in terms of it motivates them they're more likely to adhere to the bigger things that are often the more boring things then great let's do that but we would always try and start with what has the biggest size impact on your health so if we're talking about obesity for example what's going to have the biggest size impact to reduce levels of obesity obesity is multifactoral and so it is challenging because it's going to be different for every individual but for some P people they might be overweight because of emotional reasons that are causing them to eat excess calories some people might be overweight because they're having a a diet that's exclusively alra processed food that causes you to eat faster um eat more calories Etc there's so many different reasons to why people might be overweight or have high cholesterol or have type two diabetes so the major factor will differ from one individual to the other but at the heart of or kind of the foundation of nutrition I think that we know what we're all agreed is that everyone's eating too much heavily processed unhealthy food and this causes us to overeat so we know from research that if you eat um heavily processed so Ultra processed food compared to nutritionally matched food but that just hasn't been through all these levels of process you on average consume 500 calories more per day you eat your food that's very interesting is huge there was a randomized control trial so a clinical trial that actually um fed one group of individuals uh for a couple of weeks an alter processed food diet and then another group of individuals the nutritionally Matched um unprocessed diet so it had the same fat protein fiber carbohydrate um and what they found is those that were fed the ultra processed food they ate the food 50% more quickly so they hadn't had time for the uh fullness signals to say hey stop you know you don't need to eat anymore they ate 500 calories more each day and within just a couple of weeks they started to put weight on as well as it impact their metabolic Health well you see it all the time when food's been stripped of fiber like you know classic example is oranges versus orange juice yeah to try and drink 500 calories of orange juice super easy to drink 500 calories of orange juice try sit there and eat 500 calories of oranges like there's a lot of chewing at 500 calories of oranges yeah and I think that's a really lovely example of a couple of things that are going on there one you're taking out one of the really healthy nutrients from orange juice you're taking out the fiber and so what that means is therefore the fiber that would normally delay the rate at which your stomach empties uh the the sugar from from the orange juice into your stomach is is no longer there so you're having this rapid surge of blood glucose but what's also happening is because you're changing the texture of the food you're changing the speed at which you can eat it as well and so by changing that texture it means like you said you can gulp that orange juice down in seconds but it would take you a certain amount of time to eat them as whole oranges which firstly would also delay the rate at which the uh glucose is appearing in your blood but secondly it would allow the fullness signals that come from your lower intestine to actually get to your brain to say hey come on Sarah you've had enough you don't need to eat your 20th orange now is it frustrating from someone in an academic order who's typically underfunded compared to these big corporations to watch false marketing messages being proliferated to the public like orange juice is a healthy breakfast um I think what I find more frustrating is that in an effort to oversimplify messaging I think we're ultimately doing harm to the general public I think that's what's most frustrating so for example if we think about fiber fiber is good for us for a couple of reasons one is because it actually is the cell wall of plants so it has a really important structural role and one of the reasons it's really good for us is because of this structural role it has now if you add fiber into food so let's say you were to take the fiber away from for example um the orange so if we use that as a an example so you have your orange juice but you add the fiber back in you are then having fiber which will have some benefit but you've taken away its really important structural role which actually is one of the reasons why fiber is so good for us now I can make a claim saying okay it's high in fiber but actually it's not really high in what I would call particularly effective fiber because it's not doing what it was meant to do in its original Matrix in its original structure but how do I communicate that how do I say on the label oh well you know you're having the fiber back in but it's not doing the Matrix bigs blah blah blah you know no one's going to want to read that I mean I'm bored saying it um and so this is the problem that it's so nuanced with food and that's why like for example I gave you the example of the saturated fat and the dairy is we are taught to look at simple messages saturated Fat's bad for you look at the back of perfect labeling look at butter look at cheese same saturated fat my gosh they must both be bad for me but it's not that simple and I think that yes there is a lot of marketing around these heavily processed food they are designed to be tasty they are designed to leave us wanting more um and I think that we live in a current food landscape that is incredibly harmful and that it makes eating unhealthy food far easier than eating healthy food and I think it's the entire food landscape that I think we need to revisit and it has to start with some of these big companies as well rethinking how they're messaging food as well you touched on something when you were talking about obesity that it's so multifactorial that there's an emotional element to it but I think we haven't helped ourselves as healthc Care Professionals across the board because everything has been so soil outed you've had therapists dealing with emotional well-being you know siloed off from physical therapists soed off from dietitians soed off from physiotherapists each of them operating in a vacuum when the reality is they're also interconnected this was really brought home to me when I started using a continuous glucose monitor super sapients was the brand so I'd weigh out my oats for breakfast in the morning so I'd you know go to bed at night get up in the morning have my weighed portion of Oats I'd eat them and then I'd observe the effect on my blood sugar levels after eating those oats I'd wake up the next morning having slept eight hours exact same as the night before have the exact same portion of oats and i' observe a totally different effect on my blood sugar and that's when I started digging in and saying okay how much does sleep affect my nutrition it turns out it affected a massive amount an amount that's almost made the use of the continuous glucose monitor for that purpose for me a little bit redundant because now I had to play this role of you know part-time bro scientist where I had to try figur this out myself because there's not I hadn't got access to professionals to explain this to me but talk to me a little bit about how sleep affects their role of how sleep affects food and that interaction yeah so I think sleep is a great example of the how we eat that I mentioned at the beginning and how the how we eat can impact how we respond to food so if we look at sleep in relation to circulating blood glucose um as you used as an example what we know from our own research that we published a couple of years ago is that within an individual if you have a good night sleep and you have exactly the same breakfast uh compared to if you have a bad night sleep and have exactly the same breakfast you will have a lower blood glucose response so you'll have a more um a blunted blood glucose Peak that will stay sustained um at a low level for a bit longer and then you less likely to have this kind of Crash that we talk about as well two to four hours after the meal if you have a bad night's sleep even if everything else is the same like you're controlling what physical activity you've done Etc then and you have exactly the same breakfast then you have a higher blood sugar Peak that may also predispose you to having this crash there's also other things that are going on when you haven't slept well so when you haven't slept well as well the reward centers in your brain are heightened and so they need a quick fix they need kind of that dopamine hit to kind to to satisfy these reward centers so it leaves you craving for these quick fixes so what's happening is you'll crave for something like a a more you know refined carbohydrate style breakfast you're less likely to want a particularly healthy balanced breakfast so you're kind of getting a double hit going on that firstly your brain's saying hey I need a quick fix go and give me that you know pastry Etc and then when you're having that pastry because you've had a bad night's sleep you're also having a worse blood glucose response then what happens is you start on this roller coaster and you start on this roller coaster at Big Peaks and potentially big dips in glucose and this is an area that we've been doing a lot of work on which is around the dips in glucose that can happen two to four hours after having carbohydrate wi Mills and it's something that actually very few people have looked at and we've got some really interesting data around that as well yeah I've definitely observed that as well I I I hate to tag Foods as good and bad because I think when you do that you start to bring in this almost morality around eating it because you know even a you know quote unquote bad food I think eating at the right time like during exercise now it becomes you know quite a good fuel but I've anecdotally observed when I sleep poorly I wake up the next morning and I have less willpower to avoid the bad foods you know if I live very close to a Sho and I'll often go go and I pick milk and eggs and stuff up for breakfast but they have a beautiful French Bakery and the smells wafted up and 99 times out of 100 I'm like okay I know I don't need a panda r on right now with my coffee but if I've had a bad night's sleep I am quite susceptible to a panda on yeah and I think you know we should be quite gentle on ourselves in that our brain is directing us to that and you know this adage that oh it's all about willpower yes there's an element of willpower but so what having that you know panaka or that Quant once in a while it's not going to do you any harm so you've had a bad night's sleep you know for whatever reason Go Gentle on yourself and allow yourself to have it is my motto Today's Show sponsor is pillar well we're all familiar with the importance of electrolytes and carbohydrates and their role in our race preparation pillar is taken a completely different route it focuses on micronutrition ensuring we're ready to perform even before we hit the start line it's all about promoting a good night's sleep facilitating effective recovery and replenishing those crucial micronutrients so you can perform at your very very best I've been running my own personal little experiment over the past month and I've been incorporating pillars triple magnesium supplement into my evening routine I take it about 30 minutes before bed and the results I've seen are absolutely remarkable the Improvement in Sleep Quality about 10% I've seen I've been tracking my sleep with my wo poop the voice and the results are there in absolute black and white I've given this to friends they've tested it and they've all experienced the same results I wake up feeling refreshed having had a deep restart of sleep so I'm ready to attack work training and life the next day but don't just take my word for it the data from your Fitness tracker will tell you the story so if you're ready to elevate your performance and your Sleep Quality like me just go ahead and give pillar a try head to pillar performance .

Snacking, Timing, and Calorie Quality

Shop and use the code roadman on your local website for 15% off your first order if you're watching this in the US head over to the feed.com pillar and use the code roadman for 15% off that first order as well now let's get back to the show so snacking kind of has a bad rep and I kind of want to deal with maybe snacking and intermittent fast and here in the same uh you know sentence so intermittent fast and the typical protocol that's pushed online is this 18-hour fasting period with a six-hour feeding period to get that cellular autophagy and all those benefits and then snacking I think almost in the same sentence has been demonized well my understanding from reading some of your work is that snacking isn't entirely bad at certain periods in the day it's more just than that last meal of the day or you know post 8 o'clock that snacking becomes quite toxic to our Health and Longevity goals yeah so we've done quite a bit of work looking at snacking and I think snacking is something really important because 95% of people snack on average we have two and a half snacks a day if you're a snacker and 25% of calories on average comes from snacks in the UK that's huge that's a quarter of our calories and if we put that into the context of how many calories come from our evening meal is pretty similar and people spend a lot of time thinking about how they can have a health healthy evening meal what they can add in ETC but actually our snacks that we have throughout the day account for just the same amount of energy so if we can focus on the quality of the snacks and eating healthy snacks we can go a really huge way to improving our health and the research that we did tried to look at a couple of really important questions related to snacking does the frequency of snacking matter is it all about the quality or is it about the timing and so there is this question about oh you shouldn't snack we should go back to the three main meals breakfast lunch and dinner you know our ancestors didn't snack although you know there is the hunter gatherer from before that so I think it's kind of varied uh you know through history what our research shows is that having multiple snacks or another term we use for this is multiple eating events so eating or grazing throughout the day as long as you're grazing on healthy food and grazing when you're hungry rather than out of habit then our research shows that there is no detrimental effect on your health it's if you're not listening to your hunger signals and if you're eating or grazing snacking on unhealthy Foods that's where the problem arises and the problem is is that the majority of snacks that people eat are higher in unhealthy saturated fats higher in salt higher in Sugar higher in refined carbohydrates they tend to be lower in fiber lower in heart healthy oils um and stripped of a lot of the kind of bioactive nutrients that makes food so special so chemicals like polyphenols that you know have great properties in terms of improving our health and so we need to be mindful about the kind of snacks we're having but I think not so much worrying about having snacks between meals but what our research did show is that snacking late in the evening so particularly if you snacked after n9ine o'clock and we found a huge proportion of people do snack after nine o'clock that that culturally that's kind of where we've gone to isn't it where people chill out in the evening and watch Netflix and they might have you know an ice cream or a popcorn or crisps or something with that yeah so interestingly we actually found that the the kind of food people were snacking on after 9 was more unhealthy than the kind of snacks people were having before 9:00 you know which confirms you know exactly what you're saying that you know sitting in front of Netflix having some crisp a bit of chocolate Etc so firstly people are snacking on slightly less healthy snacks later in the evening but we also know that eating whether it's snacking your May meal later in the evening for most people it's not the healthiest way to eat and this is because there's a growing understanding amongst scientists of what we call um your Cadian Rhythm so Cadian biology and a really simple way to explain this is that every cell in our body has its own clock and so all of the cells that are dealing with how we metabolize food have their own clock as well and that clock is primed to work better for some things at some times of the day versus other times a day well that makes perfect sense because when I've traveled Long Haul I felt that urge to eat breakfast or lunch at a bizarre time that was local but it was actually my native time to be eating breakfast or lunch back home yeah so it's interesting there two main things that control our Cadian Rhythm so it will control the the clocks in all of these cells one is the light dark cycle and the other is the timing that we eat our food so what you'll find is some people that travel a lot for business but only maybe going for you know 24-hour period or something they might they can't control the light dark cycle within reason um and so what they can control though is trying to maintain eating at the same time that they would have been eating back at home so that therefore they're keeping largely their Cadian clock on rhythm with their typical pattern so that when they come back it's less that you know they have less chat lag um which is an interesting thing to try I'm I'm going to Vancouver on Sunday but I'm there for four days I don't think I can beat in the middle of the night an interesting group to study will be Pilots I have a couple of friends who are pilots and their dietary habits they they baffle me like their sleep and dietary habits are just so much of an outlier compared to the general population yeah so there's a whole L of research around shift workers for that same reason that they're having maybe three or four days a week where they're eating in one kind of time zone and then they're having you know two or three days a week where they're eating in a different time time zone and we actually know that for shift workers there's a really high rate of cardiovascular disease of obesity and type 2 diabetes now that's in part because of the food that many shift workers eat so it is known that many shift workers don't have as healthy a diet as non- shift workers non- night shift workers because of access to food at certain times of the night but also independent the type of food that we're eating because they're eating um you know it out of sync with their Cadian clock so with their body clock we know that that's also unfavorable for their health just being this kind of growing movement around longevity how long we live yeah and I think that is definitely welcome debate but what I'd be a little bit more concerned of is Health span and I'd almost Define that as being able to do the activities you love for as long as you can in your life like we have a local group spin for cycling and one of the guys that on at one of my friends he's 83 or 84 years old and he's still able to ride with 20 year olds and I look at that as that's goals for me that's what I want to be able to do I don't want to live to 90 but have to discontinue the activities I love at 60 in the research that you've seeing is there a difference between eating for lifespan to live as long as we can versus eating for health span to live as high a quality of life as possible yeah that's a really good question and something we're very focused on particularly at Zoe is really you know thinking about healthy years which is that Health span rather than lifespan I don't think that we can differentiate between the best diet for health span versus the best diet for lifespan uh what is going to keep us healthy the longest is the kind of diet that will also uh Keep Us Alive for the longest in most instances in my opinion it's not something I thought about if it would be different actually yeah no it was just it popped into my head H you kind of identified the spikes in blood sugar and trying to flatten those over a macro period as been one of the determinants for longevity is there anything else that you've come across in your research that's key to chronic disease prevention so we know that being overweight you know the the kind of classic things that you know again I I'm I I think that people think think oh this is boring you know we all know this but you know what we've known for years still stands true being overweight in reduces your Healthy years or your health span having elevated blood cholesterol reduces your health span um having high blood pressure significantly reduces your health span and you know 60% of people uh have slightly elevated blood pressure and don't even know it uh which is is a worry having type two diabetes reduces your health spent all of these factors that I've mentioned such as obesity blood pressure cholesterol type two diabetes are all underpinned by diet they're all underpinned by mechanisms like chronic inflammation and so I think the really good news is is that at any age we can reduce our risk of these major risk factors that reduce our health span and it's never too late and there's some great research that came out recently showing that if you follow what we it was called a longevity diet versus the UK typical diet even if you start following this longevity diet at the age of 60 you can still significantly improve your health you can increase your health span as well as um your lifespan and when we talk about longevity diet what we mean is the best of everything you know having the optimal fiber intake the optimal number of fruits and vegetables reducing your Ultra process Meats for example reducing your refined carbohydrates so taking all of the best and putting that that together into this longevity diet at any age will improve your health What A Catch ran you know how serious I take my goal setting and I know how serious you take it too so whether you're chasing Fitness or lifestyle goals and you're looking for a powerful alloy to support you on this journey look no further than heu heu has become my secret weapon for when I don't have time to prepare a balanced meal it means I get the nutrition I need without sacrificing time or taste plus it stops me from reaching for the takeaway menu I always throw a bottle of this banana into my backpack when I'm heading into the City and it stops me eating junk convenience foods that don't support my training goals it's handy it's nutritious it's 22 grams of protein it's perfect for athletes that don't have time to cook or prepare food before a training session it's convenient nutritious f Fu at your fingertips ensuring you hit your daily fueling needs Fu ready to drink has over 26 essential vitamins and minerals in every bottle making sure you get 175 health benefits plus it's made from amazing natural ingredients like sunflower seed coconut and more and the best part eight melt watering flavors my favorites the banana that's what's in my backpack at the moment you can get hu direct to your home by going to hu.com for /ro man that's hu huel.com roadman how important is variety I found myself that during periods where I'm super busy where I'm recording a lot on the podcast and I'm trying to balance my training that I've defaulted eating like a healthy diet and a well-balanced macro diet but very little variety where I'll nearly have the same breakfast every like I'll have two turkey burgers two eggs two toast every morning I'll have chicken rice and veg for every dinner and I'll have you know some sort of yogurt or fruit and nuts almost every lunch but I could go like a week two weeks three weeks where I won't have another meal outside of that so I think this goes back to a point you said earlier about major and minor impact so the major impact that um food is going to have on your health is by making sure you're getting enough fiber you're reducing your overall level of ultra processed uh uh food you're having you know fruits and vegetables now what we also know overlaid onto kind of those major Foundation s is that by having a diversity you can really optimize your diet and so whilst if you're still having adequate fiber adequate nutrients from you know unprocessed plant-based foods and reducing these healthy foods even if you're eating the same thing week on week you can still have a reasonably healthy diet by having that variety means you're exposing your body to these thousands of chemicals that we know exist in food so we know that food isn't simply a case of the four macronutrients fiber protein fat carbohydrate we know that foods contain up to about 20,000 chemicals in each food each of those chemicals interact with the other chemicals in that food and with other food that might be within the meal that you're having and each of those chemicals have different properties so if we use polyphenols for example and you might hear people often say eat the rainbow and this is because the um chemicals called polyphenols which give fruits and vegetables they pigmented color so the color whether it's the yellow the orange the greens the Reds for example each of those colors is from a different kind of polyphenol or a different chemical that has a different role in the body in improving your health and so by get getting eating the rainbow or having a variety then you're maximizing the types of different chemicals you're having that might act in a slightly different way than some of the other chemical and therefore optimizing your health we also know for another reason as well it's important which is your microbiome and the microbiome is a really uh rapidly growing area of research in an area we've focused on a lot and the microbiome is simply the trillions of bugs that are in your G and we have trillions of bugs that differ between each individual that actually have a party on all of the undigested food which is mainly the fiber that reaches our G this is why fiber is so important we also know that it eats some of these polyphenols so these different colored Parts as well of fruits and vegetables now these bacteria have really wide reaching roles in our health um many of which um have beneficial effects on our health but different bacteria which have different impacts on our health feed on different kinds of fiber or different kinds of plant chemicals and so if we have that diversity we will also be encouraging a real diverse growth of different bacteria and therefore improving different areas of our houseal more Super interesting sir very last thing before we finish up my girlfriend always says to me that if she's standing up eating biscuits beside the kettle as she's making tea the calories don't count when she's standing up it's R true in this um no is this simple answer to that um but if she's enjoying those biscuits then fair play you know something that I think we can lose sight of in a quest to be healthy is actually about the pleasure of food and food is there to be enjoyed as well as to be healthy you know it's part of our culture it's part of our society it's part of our emotions it should be there for Joy um and I often say to people that if a food is too healthy to be enjoyed it's just not healthy at all and so if your girlfriend enjoys having those biscuits whether she's standing up having uh while the kettle's boiling or sitting down then in moderation it's fine Sarah thank you very much for your time I'm gonna link up your website podcast YouTube channel and all the amazing work you guys do at zo in the description so people can check it out thank you so much for your time pleasure thank you

FREQUENTLY ASKED QUESTIONS

does meal timing affect blood sugar levels+

Yes, and the effect is significant. Dr Sarah Berry explains that when you eat matters as much as what you eat, with meal timing directly influencing how sharply blood glucose rises and falls after a meal. Eating earlier in the day and avoiding late-night meals consistently produces better glycaemic responses.

does eating protein before carbs lower blood sugar spikes+

Eating fat, protein, or fibre before carbohydrates slows gastric emptying, which blunts the glucose peak that follows a meal. Dr Sarah Berry references ZOE research showing this simple change in food order can meaningfully reduce harmful spikes without changing what you actually eat. It is one of the most practical and low-effort ways to improve your metabolic response.

why do people have different blood sugar responses to the same food+

Individual blood glucose responses to identical meals can vary up to 20-fold between people, according to ZOE studies discussed by Dr Sarah Berry. Differences in gut microbiome composition, genetics, and metabolic health all contribute to this variation. This is why personalised nutrition approaches tend to outperform generic dietary guidelines.

does poor sleep make you process food worse+

Sleep deprivation worsens your metabolic response to the same food you would handle well when rested. Dr Sarah Berry highlights that a bad night's sleep impairs insulin sensitivity and amplifies blood glucose spikes the following day. Prioritising sleep is therefore a direct nutritional strategy, not just a general health recommendation.

NEVER MISS AN EPISODE

Weekly insights from the podcast. The stuff that actually makes you faster.

READ THE GUIDE

The written companion to this episode.

Caffeine and Cycling Performance: The Dosing Protocol That Works

Caffeine is the most widely used performance enhancer in cycling — and one of the most evidence-backed. But most riders use it wrong. Here's…

Hydration for Cyclists: How Much to Drink and When It Matters

A 2% drop in hydration increases heart rate by 5-10 BPM at the same power. Here's exactly how much to drink, when to drink it, and why most …

In-Ride Nutrition for Cyclists: How Much to Eat and When

Most cyclists underfuel on the bike. Here's exactly how many carbs per hour you need, how much fluid, and the strategy for every ride durati…

USE THESE TOOLS

RELATED EPISODES

More episodes you might enjoy

Episode

Nutrition28:16

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

Anthony & Sarah are back for Rider Support. They discuss why hookless rims keep causing tyres to explode, a bizarre cheating cycling team are caught out and new speed limit restrictions could put the future of Time Trials in jeopardy.

with Rider Support

Episode

Nutrition56:13

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

Todays guest is Nutritionist Uri Carlson and during this chat we aim to answer one fundamental question, how cyclists can lose weight without sacrificing muscle and power. We'll explore the essentials of weight loss, nutrition strategies, and the timing of nutrient intake. Expect insights on...

Episode

Nutrition51:37

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

In this episode we tackle a surprising nutrition pitfall: the one common food many endurance athletes eat that could be slowing them down. We also dive into essential macronutrient strategies, timing, and portioning for endurance events, with insights into carbohydrates, protein for recovery, and...

LIKED THIS EPISODE?

Join the Clubhouse to discuss this episode, ask Anthony your questions, and connect with serious cyclists.

Join the Clubhouse — Free More Episodes

Key Takeaways

Individual responses to food can vary by up to 20-fold—what works for one person's metabolism may be completely different for yours, making personalized nutrition crucial

Eating ultra-processed foods causes you to consume ~500 more calories daily and eat 50% faster, bypassing your fullness signals before your brain registers satiety

Sleep quality directly impacts blood glucose response: a poor night's sleep creates higher blood sugar peaks and increased cravings for refined carbs, even when eating identical meals

Meal ordering matters—eating fiber, fat, or protein before carbohydrates slows glucose absorption and prevents harmful blood sugar spikes

Evening snacking after 9pm is particularly problematic due to circadian rhythm disruption; most people also choose less healthy snacks later in the day

Food diversity optimizes health by exposing your body to thousands of beneficial plant chemicals (polyphenols) and feeding diverse gut bacteria—but adequate fiber and reduced ultra-processed foods are the foundation

Expert Quotes

"I think having spent 25 years in nutrition research where I always focused on what we call the average response...suddenly delving into how individuals respond differently has been a real eye opener in terms of the size of the difference—you can see like a 20-fold difference in how you might respond to a food versus how I might respond."

"The problem is that people do need simple messaging but also people want quick fixes when it comes to nutrition...there isn't a silver bullet it's not that simple. Food is complicated, how we respond is complicated."

"If a food is too healthy to be enjoyed it's just not healthy at all...food should be there for joy as well as to be healthy."

KEY QUOTES

“we know from research that if you eat heavily processed so Ultra processed food compared to nutritionally matched food but that just hasn't been through all these levels of process you on average consume 500 calories more per day”
Dr Berry — Nutrition researcher at ZOE

“those that were fed the ultra processed food they ate the food 50% more quickly so they hadn't had time for the fullness signals to say hey stop you know you don't need to eat anymore they ate 500 calories more each day and within just a couple of weeks they started to put weight on as well as it impact their metabolic Health”
Dr Berry — Nutrition researcher at ZOE

“if you have a good night sleep and you have exactly the same breakfast compared to if you have a bad night sleep and have exactly the same breakfast you will have a lower blood glucose response”
Dr Berry — Nutrition researcher at ZOE

FREQUENTLY ASKED QUESTIONS

does meal timing affect blood sugar levels+

does eating protein before carbs lower blood sugar spikes+

why do people have different blood sugar responses to the same food+

does poor sleep make you process food worse+

FORGET WHAT YOU EAT, IT'S WHEN YOU EAT THAT CHANGES EVERYTHING | DR BERRY

Key Takeaways

Expert Quotes

CLAIMS FROM THIS EPISODE

KEY QUOTES

How Individuals Respond Differently to Food

Snacking, Timing, and Calorie Quality

FREQUENTLY ASKED QUESTIONS

NEVER MISS AN EPISODE

READ THE GUIDE

RELATED EPISODES

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

RELATED CONTENT

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

LIKED THIS EPISODE?

FORGET WHAT YOU EAT, IT'S WHEN YOU EAT THAT CHANGES EVERYTHING | DR BERRY

Key Takeaways

Expert Quotes

CLAIMS FROM THIS EPISODE

KEY QUOTES

How Individuals Respond Differently to Food

Snacking, Timing, and Calorie Quality

FREQUENTLY ASKED QUESTIONS

NEVER MISS AN EPISODE

READ THE GUIDE

RELATED EPISODES

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

RELATED CONTENT

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

LIKED THIS EPISODE?

FORGET WHAT YOU EAT, IT'S WHEN YOU EAT THAT CHANGES EVERYTHING | DR BERRY

Key Takeaways

Expert Quotes

CLAIMS FROM THIS EPISODE

KEY QUOTES

1.How Individuals Respond Differently to Food

2.Snacking, Timing, and Calorie Quality

FREQUENTLY ASKED QUESTIONS

NEVER MISS AN EPISODE

READ THE GUIDE

RELATED EPISODES

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

RELATED CONTENT

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

LIKED THIS EPISODE?

FORGET WHAT YOU EAT, IT'S WHEN YOU EAT THAT CHANGES EVERYTHING | DR BERRY

Key Takeaways

Expert Quotes

CLAIMS FROM THIS EPISODE

KEY QUOTES

1.How Individuals Respond Differently to Food

2.Snacking, Timing, and Calorie Quality

FREQUENTLY ASKED QUESTIONS

NEVER MISS AN EPISODE

READ THE GUIDE

RELATED EPISODES

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

RELATED CONTENT

WHY TYRES KEEP EXPLODING & CHEATING PRO'S CAUGHT | RIDER SUPPORT

HOW CYCLING CAN SABOTAGE YOUR WEIGHT LOSS (AND THE FIX)

SPORTS NUTRITIONIST "THE ONE FOOD THAT'S SLOWING US DOWN"

LIKED THIS EPISODE?

How Individuals Respond Differently to Food

Snacking, Timing, and Calorie Quality

How Individuals Respond Differently to Food

Snacking, Timing, and Calorie Quality