Microbiome expert: How to reset your gut overnight | Tim Spector

The old way of thinking about nutrition is the way doctors are still being taught that essentially there's only four things you need to know. It's calories, how much

fat there is, how much protein there is, and how much sugar there is. If you get those four things right, everything else will follow. We've been following that advice for the last 40 years, and it's

been a complete disaster. It's only really helped the food companies sell us more crappy products, and it's led to a disaster of unbelievable scale for the public

health. My name's Tim Spector. I'm an MD. I'm a professor of epidemiology at King's College in London, and I'm also co-founder of the nutrition and gut

health company Zoe. >> Eight tips for maintaining a healthy gut ecosystem. >> Real food, unlike fake food that is made of some a few ingredients, contains

thousands of chemicals. And all of these play a role in our body because they then nourish the trillions of microbes inside our gut to produce thousands of other chemicals that our

body can't produce. It's only by focusing nutritional health guidelines on this new organ of our body, our gut microbes, that it all makes sense. We have to have a seismic shift in our idea

about nutrition in order to make healthy progress, and focus on gut health, and what are the key principles to improve all of our gut microbes, which will help us.

As I've been studying the gut microbiome, I've been obviously thinking of how I can translate that science into progress and practical tips for people in various

ages and states of how they can improve their gut health. The first one is what we call mindfulness. And this seems a bit strange. What

what's he talking about mindfulness for? Well, I remember when I started to change my diet, I decided to be vegan. It was an easy way to change your diet.

As a a temporary fix if you like cuz it meant that when I was going to medical conferences, I would stop and think before I just took something from that tray, from that

buffet. I would say, "What's in it? Uh was there meat in it or is there dairy in it?" And we don't need to be that extreme. All you need to do is to think about what you're eating

just for a second before you grab it or you put it in your mouth. So, mindfulness in this context means just stop and think, "Am I hungry? Do I need this?

What's in it? You know, and what are what are those contents? Are they going to have an effect on me? And then what

effect is that going to have on me if I do eat them?" So, these sort of three steps that I think are important in mindfulness is an important realization that food is

much more than just calories. Uh is it going to affect my mood? How am I going to feel in 3 hours time? Uh what what are the long-term consequences? And also, is it going to

be really tasty? Am I going to really enjoy it? Or am I just being forced by marketing, by big food to eat this rubbish that I don't really want? So, there three

uh steps in this this concept of mindfulness. We just want people to stop and think. That's number one. So, the second principle, probably the most important that we've found

scientifically, is to eat a diversity of plants. It's not about eating the same plant many times a week. We think that the science is pointing us

to something around 30 different plants a week gives you optimum gut health. This is a study that I took part in with the British Gut and the American Gut about 10 years ago where we saw that the

sweet spot for gut health was people eating around 30 different plants a week. It looks like it might be slightly more than that, but certainly 30's a really good target. It turns out it

doesn't matter if you're vegan or vegetarian or an omnivore, it's the people that eat the most plants have the healthiest gut, which I think is is really interesting. 30 plants to

many people say, "That sounds way too much." The average American probably has between 10 and 12 plants a week. How do I get, you know, how do I get over

double that? Well, you got to remember what a plant is. It's a it's not only a fruit and a vegetable, but it's also a nut. It's every different type of seed.

It's an herb. It's a spice. It's even things like coffee, which is a fermented bean. So, when you just change your mind a bit about what plants are, then it becomes easier and

fun to add them to your plate. Think about more rather than less. Most diets are all about excluding things. Uh what we're trying to do for our gut health is to in- include more things.

We've got little microbes just waiting around for that bit of baobab or that particular nut or seed or berry, uh the chemical that comes from it. So, the more you can give your gut microbes,

the better. My third guideline is to eat three fermented foods daily. So, I've spent the last 3 years researching fermented foods and have a

book on that subject, and what was really interesting is I I didn't think it was a topic worth discussing 3 years ago because the science wasn't really up to it.

But, I've been convinced by a couple of studies. The first was from my colleague Christopher Gardner at Stanford, a very detailed but small study of adults who were told to eat five ferments a day,

comparing that group to a high-fiber group. And what they showed was that not only did the gut health improve in the fermented group, particularly the immune system was impacted, and they had around

25% less inflammation. So, suddenly moving from anecdote and lots of small, not very good studies in the literature uh that were all pointing the same way that fermented foods were good for you,

to suddenly a mechanism that this can really impact your immune health in different ways to just rather than just eating lots of fiber and plants. People think, "What is a ferment?" A fermented

food is something that's been transformed by microbes into something better. So, you transform milk into cheese, much more interesting than milk. You transform grapes into wine.

Uh you're transforming cabbage into sauerkraut. So, think the four K's, kefir, uh kimchi, kraut, kombucha. Kombucha is uh

fermented tea, which is all really good for you. Most cheeses, if they're not uh made artificially in in in factories, are good. Yogurt is great. All the soy

products that you see in Japan, miso paste, all these krauts and pickles that are fermented in salt are really good for you. So, variety is important. They've all got

plenty of different microbial species, and they're probably better for you than just taking probiotics from the pharmacy or the drugstore. So, my recommendation is to

build up to three ferments a day as an extra boost for your immune system and your gut microbes. I'm a big fan of fermented foods now because the science has finally caught up.

Fourth guideline is to diversify your protein. We're going through a protein craze at the moment where every product has added protein in it. Every

American thinks they're deficient in protein. And there's nothing wrong with protein. It's not particularly harmful, but if you don't need it, you lose it. You

can't store it, so you pee it out or it gets converted to fat. If you are trying to get more protein and perhaps 10% of people are lacking in protein because they're unwell, they might be elderly,

they're trying to build body mass or trying not lose it too much as they're on these weight loss drugs, then my view is you should be try to

think about other protein sources rather than just red meat. The one that comes to mind are beans and lentils, things that have really high protein

content, but also contain lots of fiber. This means your microbes can actually use that at the same time as your body's getting that protein. So, that's a real reason why we should be switching eating

many more beans and pulses than we are currently. They're very cheap, they're accessible, they're good for the planet, and our microbes love them. Guideline number five is focus on

quality, not calories. For decades, we've been obsessed with the calorie as the main source of describing food and nutrition about whether it's healthy or not. There are hardly any

uh nutrition scientists who now believe in the dominance of the calorie. It's only a tool for the food companies to make rubbish food seem more healthy because it is lower in

this magic term. The science tells us that these in the vast majority of people fail. It's really impossible for most people

to follow a calorie restricted diet for more than a few weeks. And even if they do lose weight as most people do, uh that actually everybody regains it

because your body's appetite signal is turned up. The brain has finely tuned to know if you're not getting enough energy and it switches up its thermostat to ramp up

your hunger signals. Your body is designed by evolution to overcome that pure calorie signal. The other problem with calories, not only the fact that it's

it's virtually impossible to calorie count and and lose weight, is that it disguises the food in ways that gets us to stop thinking about the

quality of what we're eating. And that's what the food companies have been doing for the last 40 or 50 years, trying to switch our thought away from the fact that they are

just making this crap food out of a a few ingredients that have government surpluses away from the food we should be eating, which are

whole foods, which is what our gut microbes want to eat. They want to eat a variety of foods that are in their original state, that have the the casing that contains most of the fiber, they

want the skin on it. This is where most of the nutrients and ingredients are that we need for our bodies to work really well. This is a really important step as people

try to disregard the calorie, which effectively doesn't have a major role in our any of our plans and we ignore the calorie completely. So, tell people it doesn't matter. It's all about

the quality of the food, how it's going to impact your gut microbes. And once you do that, it's very liberating for people to think, I don't have to worry about

this. And generally, if something's got low calorie on it, it's a poor-quality food. You should be avoiding it. Number six, avoid high-risk processed foods or high-risk ultra-processed

foods. These are the foods that make up 50 to 70% of the American diet, higher in kids, and most those foods are really harmful for us. There isn't a universal definition of an ultra-processed food.

We think that ultra-processed food itself is is too broad a term because it most people use as anything that has got an additive in it. Some of those additives can be like vitamin C,

therefore not particularly bad for you. Whereas others are dreadful. And the worst ones, the ones we categorized that make up 25% of

the American diet, have a number of components that make them particularly harmful. Remember, these are foods that are mainly made from the cheap

ingredients that our our government subsidized like like maize, like soy, and wheat, and sugar.

These are things that are plentiful and taxpayers are paying for them to be cheap, and they have surplus of it, so they've got to make create foods with them. And they do that really

effectively, and they try and upsell them by adding additives to them that change their color, and they change their texture, and they change their taste.

And some of these additives are not too bad. Others are quite unhealthy, and others are really unhealthy for us. Some of them are associated with cancer, some of

them associated with mental health problems in kids. You have emulsifiers which glue them together, which are bad for our gut microbes. You've got artificial sweeteners which

many of them developed from the petrochemical industry, which our bodies are not used to, that cause our microbes to produce funny, strange chemicals in response, and are generally harmful.

You've got others that we still don't know how bad they are. That's That's the additives. Then you've got uh the hyperpalatability that the companies

use a mixture of salt, sugar, and fat in those combinations to make that food override your normal fullness signal. So, they do this very deliberately. We all know we've eaten a big bag of chips

or whatever it is in front of the TV, and it's it's got potato, which is starch in it. It's got um salt. It's got usually um so some uh fats in there. And it's that sugar,

salt, fat in the perfect combination that these brilliant food scientists have created that will tickle our brains into uh thinking we can keep eating them, and we just don't get full. So,

hyperpalatability is a component of 70% of these foods. The other component that you need to be looking out for is is it something that you can eat super quickly. Uh its

structure has been taken away, so you strip off all those bits of plants that make it necessary to chew it, and you've just got the inside uh bit, so we end up eating baby food. They melt in your

mouth, dissolve away. You can keep eating them without even noticing it, without exercising your jaw. And then, finally, the best from the food company's point of view are foods

that you can get lots of energy in really quickly without noticing it. And this is called calorie density. The worst offending foods have those. So, these are the the four categories, the

ones to look out for, the ones that have all of those components, and that makes up 25% of the American diet. Breakfast cereals for kids, most children's yogurts, most

savory snacks, most cookies, uh most ready meals, most sodas and drinks, even if they are low-calorie. So, not only is it bad for

your gut microbes, it's also going to make you uh keep eating and become obese and have all those problems of diabetes, etc. I don't think it's realistic to cut them

all out completely, and my view is that you know, you can still have the odd uh treat, but don't have any of these as a regular part of your diet.

Number seven, try and eat the rainbow. You may have heard that before, certainly been around a while, but we now know why it's good to eat the rainbow. Rainbow plants and uh

especially fruits and vegetables have rich colors, and that's what we're looking for when we're trying to select something to put on your plate is to try and get as bright and as varied as

possible. Because plants that have these bright colors tend to also have high levels of a defense chemical called polyphenols. Plants, like humans, you know, have a defense mechanism, and this

is their defense mechanism. They are fighting off insects and sunlight and drought drought etc. with these chemicals that turn out to be

actually very good for us. They used to be called antioxidants, which is a rather vague scientific term. We now know that our microbes can use these polyphenols

as a form of fuel. If they're getting this, it's like they're getting extra gasoline. And so this engages all our microbes to be healthier. So as well as breaking

down the fiber in the these plants, they're also getting these extra chemicals, which is acting as a fuel, which makes them even more productive. So nature's given us these clues. Bright

colors, for example, you got a store uh you got an iceberg lettuce there and you've got a rosso lolo, an Italian one with lots of purple uh leaves on it. Always go for the brightly colored one.

That will have a thousand times more uh polyphenols than the uh ubiquitous iceberg lettuce whose only advantage is that it stays forever in your fridge. It has no nutritional value

other than that. It will come still be there after your vacation. The other clue in nature is they can be bitter as well. So slightly bitter tasting plants like your broccolis, the cruciferous

vegetables uh nuts and seeds you've got uh extra virgin olive oil, which is my oil of choice, is really high in polyphenols. The best ones will make you slightly cough and you want them to be

really nice and young. You've got dark chocolate. Over 70% is generally healthy because that cacao bean has really been um fermented and is uh really strong in

polyphenols, as is coffee. If you like a drink uh the the the only one I'd recommend for your gut health is probably red wine which has high levels of polyphenols

again in moderation. So there are the tips that nature's given us to identify why eating the rainbow and bitter foods are actually good for us. The final tip is try and give your gut a

rest and by that I mean time restricted eating. 20 years ago and certainly when I was at a medical school was the idea that we should be

grazing not feasting. Things have now changed and we now realize that constant grazing is what your gut microbiome doesn't like at all. We know how important sleep is for our

health getting 8 hours a night can really extend your lifespan and improve your immune system well the same is true for our gut microbes. They have a circadian

rhythm they actually go to sleep and they need this time to repair the gut. So if it's eating all the time and you're having late night snacks early breakfast they're not getting the

natural time they need that our ancestors had for millions of years to clean up our gut particularly the lining of the gut where the mucosa is. This is really important

as a an immune barrier and the healthier that is the healthier generally our immune responses are. So give your gut 12 to 14 hours to recover overnight and this is the basis of time restricted

eating. The way time restricted eating seems to work is through a number of mechanisms. The first is by leaving that gap in time your microbes

are not focusing on eating and you have a defense team that comes out at night a bit like in American football you have a different teams for offense and defense

defense comes out it cleans up the lining of your mucosa. That tidies up the gut lining, makes it more efficient, helps the immune system. You're also getting metabolic advantages, so that

uh your gut health is generally better the next day because it's all been tidied up for you. There isn't that much debris lying around, and you get less unhealthy bugs over time. It also seems

to be uh better for your mental health. A lot of this is uh anecdotal, but we did do a large study in Zoe of

over 140,000 people, asked them to do time-restricted eating. A third of people hated it. They were snackers, and they just found it really difficult.

A third loved it and are still doing it years later. And what we we learned was the people that that were adhering to it had improved mood, energy, and less hunger from doing it.

So, there do seem to be other benefits that we still uh are looking at. And it also helps you avoid snacking, and we know that uh

mindless snacking accounts about 25% of calories in in in the United States and the UK. So, it just makes you a bit more thoughtful about what you're eating if you're trying to give your gut microbes

a rest. Time-restricted eating is a form of intermittent fasting, but you're not restricting calories. You're just eating the same food you would normally eat, but in a more limited time frame.

So, for people wanting to give it a go, I would say the easiest thing is to start with a little rule, like leave at least 2 hours before going to bed, where you're not eating anything else except

maybe some black tea or or or water. That way your gut will have a chance to recover, and hopefully you'll notice the difference the next morning. And if that works, then you can extend it and maybe

say, "Okay, I can try this for a 12-hour overnight fast as well. We are moving to the idea that many people can do very well just having two main meals a day

or maybe combining breakfast and lunch, the concept of brunch. Many people are enjoying around the world and say, "Actually, I feel quite good at the weekend when I do that. I don't

necessarily need to eat first thing in the morning." And I think we're realizing that this this idea of three big meals and maybe three snacks events has been forced on us by the food

industry. Mr. Kellogg was probably the first one to say that everyone had to have a breakfast before doing anything, otherwise you'd be unable to work.

>> [music] >> I personally find you know, I'm doing this interview now and I decide not to have breakfast cuz I'm actually sharper

uh, when I haven't eaten just before it. So, for me uh, two or three meals, no major snacking events, eating relatively late. I eat until

say, finish eating at maybe 8:30 at night and then would try and not have anything to eat before about 10:30 the next morning. That suits me. When we asked the 140,000 Zoe members what they

preferred, they found 2/3 preferred that same rhythm. 1/3 uh, couldn't miss breakfast. They said, "Oh,

I really like my breakfast. I'm hungry when I get up. I want to have my breakfast, but then I'll finish eating about uh, 6:00 6:30." And so, people have

different rhythms. As we discovered, I think there is a bit of personalization to this and you have to find the one that suits you. But, my advice would be don't follow what the big food companies

want you to do. Uh, do experiment. Find out what works for you and follow that. So, there you go. They're are eight guidelines. The key message is you've

got to eat for your gut microbes. If they're happy, you're going to be happy. >> Want to support the channel? Join the Big Think members community where you get access to videos early, ad-free.