Alanna Collen [ 13 NOV 2018 | Obesity Epidemic | 12:51 ] We all know why people get fat, don’t we? It’s because they eat too much and they move too little. It’s because they eat the wrong foods. It’s because they are greedy and they are lazy.
And we all know what they need to do to be lean, they need to eat less.
They need to cut down on fat and sugar processed foods. Maybe cut down on eating on certain days of the week — or is it gluten?
Hold on on a second.
Whatever it is, whatever nutrient we cut down on, we just know that they need more willpower. That’s the message that we’ve been getting for years.
But we also know that diets don’t work.
Multiple studies show that it’s extremely difficult to lose weight and even the people who do manage it usually regain that weight –and more –within a couple of years.
So what if we’re looking at this the wrong way around?
I’m going to show you a couple of maps.
So this is the spread of obesity across the United States over the past 30 or so years.
In the top left you can see a map that has a lot of white space. That’s just where they haven’t recorded how many people are obese because it doesn’t seem to matter very much at this point in time.
The blue bits are where people are around 10% obese.
And you can see, as time goes on, that the maps get bluer and then yellow and then red.
That’s showing that people are getting fatter.
So by 2010, nearly 10 years ago, now we’re going towards the sort of 30% obese point — that’s a big change in not very long — and this is only obese people, this isn’t including people who are simply overweight. Something like 7 in 10 people in the United States are overweight or obese.
It resembles the spread of an infectious disease.
Across the United States.
I want to consider an alternative to this.
We’ve been dieting and exercising for nearly 70 years.
We’ve been eating cleanly.
We’ve been doing everything that the media tells us to do, that our governments tell us to do, in order to lose weight and be lean and we just keep getting fatter.
What if we’re thinking about it the wrong way around?
What if weight gain isn’t a symptom of energy excess but a disease of energy regulation?
What if there’s something in our bodies which is making us gain weight and as a response we need to eat more to satisfy it?
I want to give you a new view on obesity that isn’t dependent on us being less sinful, less greedy, less lazy — doesn’t involve willpower.
I want to give you a view where you see obesity as some kind of biological change.
I think there are multiple reasons for this change and I’m going to share one of them with you today which is the role of our gut microbes in controlling our weights.
We’ve all heard a lot about gut microbes in the last few years.
We know that they’re about 100 trillion of them living in us and on us and most of them live in our guts and they are responsible for keeping us healthy.
They protect us from allergies.
They stop us getting autoimmune diseases.
They even control our mental health and our behavior and — importantly — they seem to be involved in regulating our weight.
So I want to show you this picture of some mice.
Those two mice in the middle though –and the middle band– they are sisters.
They’re genetically identical and they have the same access to food and to exercise as one another.
They’re also germ-free.
That means that they were born in a sterile bubble.
They have no gut microbes in them whatsoever — which means that we can colonize them how we want to.
So in this experiment the scientists took a group of women who were twins and, in each twin pair, one was obese and the other was lean and they transferred the microbes of these women into germ-free mice.
The mice that received microbes from the lean women remained lean and the mice which received microbes from the obese women became obese.
And they did not eat more food.
This tells us something extremely important about how obesity works.
It’s the microbes that made their bodies store more fat.
The mice didn’t suddenly become greedy and lazy.
They didn’t start eating chocolate and chips.
They just got new microbes –and that made them fat.
We can actually see the same kind of effect in pregnant women.
As women approach the end of their pregnancies they need to lay down fat in order to nourish their babies and to prepare for breast feeding.
So in pregnant women–if we look at their gut microbes– they are actually, as they get through their pregnancy, becoming more and more like the gut microbes of obese people and that enables them to not actually need to eat for two.
Their microbes are doing it for them.
They’re transforming the way their body works in order to enable them to store more fats for their baby.
So how do they do this?
Firstly, and most simply, we simply extract more food — more energy –from the food that we eat.
So if you take a germ-free mouse –and you just stick some microbes in there– it immediately becomes fatter and it also stops eating so much food — eats less, gets fatter.
So when you look at a nutrition label and it tells you that something’s got 100 calories in it, take that with a pinch of salt because it’s your body and your microbes that determine how many calories are in that food.
The second thing that they do is they affect our appetites.
When you eat some plant-based food that’s high in fiber you are feeding your microbes and they then turn that food into chemicals which satisfy your appetite so you feel full.
Because you have fed them.
The third thing they do, which I think is the most important, is they affect the amount of energy that your body chooses to store as fat.
If you have an unhealthy microbiome –that allows chemicals from your gut to get into your bloodstream– it annoys your immune system, it starts to react and that actually changes the way that genes in your fat cells work.
It tells those fat cells to store more energy as fat.
So this is obviously pretty important stuff and it’s important to figure out what it is that we’re doing to our microbes to damage them in the first place so that they can do these things to us.
In the West we know that people have much less diverse microbiomes than people do in more rural pre-industrial parts of the world.
And we even know that people in the West who have less diverse microbiomes are less healthy and more likely to be overweight.
So obviously something is damaging the diversity — the number of different kinds of bacteria that are living in our guts.
The most obvious thing I’m going to tell you about to – the most obvious thing –is antibiotics.
In the United States they eat 452 million FEWER chickens each year –than they would have to if it weren’t for antibiotics.
In the 1940s soon, after antibiotics were mass-produced, farmers quickly realized that if they gave antibiotics to their farm animals, they got fat.
And so now in much of the world’s farm animals –that are being raised for their meat –are given antibiotics on a daily basis to make them gain weight.
In the 1950s, some doctors who were looking after premature babies thought maybe this could help these little babies who were struggling to gain weight.
So they started giving antibiotics to the babies and –sure enough –they got fat.
And in the army, doctors were wondering whether they could help their soldiers to resist disease by giving an extra dose of antibiotics every day to make sure that they didn’t succumb to infections.
Being the army they recorded everything.
They discovered that, actually, not only did it not help them to resist disease but also it made these soldiers fatter when they were taking antibiotics.
You might think that we would take these things as a warning — that antibiotics are changing the way our bodies work and affecting our weights.
But apparently not.
In fact we know that it’s true.
In mice as well, if you give them penicillin, they get fatter.
We know that it’s not the drugs themselves –because if you then take those gut microbes, from the fat mice that have had the penicillin, and put them into a germ-free mouse –that mouse gets fat too.
Even though it’s never touched the antibiotics.
And we know that it happens in humans too.
Women who take antibiotics in pregnancy are almost –their children are almost twice as likely to be obese as women who didn’t take any antibiotics in pregnancy.
The other thing that I want to talk to you about…
I should say first of all that antibiotics, antibiotics are absolutely life-saving drugs and they are essential for us.
But we already know that they’re causing antibiotic resistance.
And that’s a massive problem.
And we need to take onboard that they can also have an impact on our health.
So the other thing that’s interrupting our microbiomes — and stopping them from being as healthy as they could be– is food.
So I know I’ve been trying to persuade you that diets don’t matter but here’s my caveat:
What you feed your microbes does matter.
Our food –most of it– is absorbed in our small intestines.
That’s where it gets broken down by our own enzymes and gets into our bloodstream and nourishes us.
But fiber, which comes from plant foods, passes straight through.
It can’t be broken down by us.
And so it goes on to our large intestines and there it feeds our microbes and as a result of that they can then give us the benefits of the chemicals that they produce from that food.
So those chemicals calm our immune systems.
They tell us that we feel full.
They even send messages to our brains to make us feel happy.
And they control how much fat our fat cells store — crucially.
So we know that our ancestors ate around 100 to 200 grams of fiber – per day.
But we in the West struggle to eat 20 grams of fiber per day.
So our microbes are really missing out on their food source.
And we know it matters too.
When you add fiber to the diets of mice– who are being fed at an extremely high fat diet – they resist obesity.
And humans who have a lower fiber intake are more likely to be overweight.
So what I want you to take away is that we are looking at obesity the wrong way around.
We’ve been dieting.
We’ve been exercising.
We’ve been blaming ourselves for our sinful, greedy, lazy natures and none of it’s working.
So maybe we should be looking at it the other way around and thinking about our microbes and other things that are affecting our biology and changing the way we store fat.
And perhaps that then goes on to make us want to eat more because we’re not getting the benefit of that energy.
One thing’s for sure: if you look after your microbes you’re looking after yourself.