Giles Yeo

So 200,000 people in the UK, a million people in the United States will carry mutations in this MC4R gene, making them more likely to end up with obesity. So that at 18 years old, if you carry a mutation in this MC4R gene, you are on average... 18 kilos heavier, 40 pounds heavier at 18 years old on average. And that's 200,000 people in this country. So it's not super common, right?

So 200,000 people in the UK, a million people in the United States will carry mutations in this MC4R gene, making them more likely to end up with obesity. So that at 18 years old, if you carry a mutation in this MC4R gene, you are on average... 18 kilos heavier, 40 pounds heavier at 18 years old on average. And that's 200,000 people in this country. So it's not super common, right?

It's still 99.7% of the people's body weight's not determined by this. But there are a lot of people's body weights who are dependent on this specific gene. But it is a tunable system. So it's a little bit or a lot means that you're either slightly heavier or a lot heavier.

It's still 99.7% of the people's body weight's not determined by this. But there are a lot of people's body weights who are dependent on this specific gene. But it is a tunable system. So it's a little bit or a lot means that you're either slightly heavier or a lot heavier.

Yes, undoubtedly so. So there is certainly what we call, it used to be called a set point hypothesis, meaning that each of us has a weight we actually protect. It's probably more nuanced than that. It's a set range. There's a range that you can actually range that we find easy to keep to the weight. So in other words, I'm not thinking about my body weight at the moment.

Yes, undoubtedly so. So there is certainly what we call, it used to be called a set point hypothesis, meaning that each of us has a weight we actually protect. It's probably more nuanced than that. It's a set range. There's a range that you can actually range that we find easy to keep to the weight. So in other words, I'm not thinking about my body weight at the moment.

And this is the weight that I am, but I wish I was half a stone or a stone lighter. But if I lost that half a stone, I would then have to think about food all the time to keep that half a stone off. Whereas I get half a stone more and I don't raise my weight anymore. So that's the idea where there is a weight range is easy to protect. And each of us is different.

And this is the weight that I am, but I wish I was half a stone or a stone lighter. But if I lost that half a stone, I would then have to think about food all the time to keep that half a stone off. Whereas I get half a stone more and I don't raise my weight anymore. So that's the idea where there is a weight range is easy to protect. And each of us is different.

There are some people who are skinny. There are some people who just find it more difficult to say no to food than others. That's pretty much it. So some people's thermostat in food is set a little higher than others. And you defend that thermostat, 25 degrees versus 20 degrees. And there's really next to nothing you can do. You can shift from 25 to 24 and a half.

There are some people who are skinny. There are some people who just find it more difficult to say no to food than others. That's pretty much it. So some people's thermostat in food is set a little higher than others. And you defend that thermostat, 25 degrees versus 20 degrees. And there's really next to nothing you can do. You can shift from 25 to 24 and a half.

And maybe after Christmas, you're 25 and 0.5. And so you shift around there. But the likelihood of you getting down to 20 and staying there, you can get down to 20 if you do some stupid diet. But the moment you ping, you ping right back up again. So we do defend. There is very, very little choice in inverted commas in where we end up with the body weight over a lifetime.

And maybe after Christmas, you're 25 and 0.5. And so you shift around there. But the likelihood of you getting down to 20 and staying there, you can get down to 20 if you do some stupid diet. But the moment you ping, you ping right back up again. So we do defend. There is very, very little choice in inverted commas in where we end up with the body weight over a lifetime.

Any given meal, we have a choice, you think, right? Pizza or no pizza, pizza or no pizza. But over thousands of feeding events, there's very little choice.

Any given meal, we have a choice, you think, right? Pizza or no pizza, pizza or no pizza. But over thousands of feeding events, there's very little choice.

A, weight is inexorably up, okay? Even though we've stopped growing when we're 18 years old. Actually, there's some later science. I used to, if you would ask me the question five years ago, I would have said that by the time we hit 40 or 50, our metabolism starts to dip. That's part of the reason. That's not true. As it turns out, our metabolism doesn't start to dip till we're 60.

A, weight is inexorably up, okay? Even though we've stopped growing when we're 18 years old. Actually, there's some later science. I used to, if you would ask me the question five years ago, I would have said that by the time we hit 40 or 50, our metabolism starts to dip. That's part of the reason. That's not true. As it turns out, our metabolism doesn't start to dip till we're 60.

But what happens as we get older are a number of different things. First of all, we tend to get richer. We tend to get more money. We tend to sit on our arse more, okay, just in terms of the type of jobs we do, okay? And because of both of those things, we tend to exercise less because we're busier, and so we lose muscle mass. Those are all three things.

But what happens as we get older are a number of different things. First of all, we tend to get richer. We tend to get more money. We tend to sit on our arse more, okay, just in terms of the type of jobs we do, okay? And because of both of those things, we tend to exercise less because we're busier, and so we lose muscle mass. Those are all three things.

Metabolically, the most active part of your body are the muscles. So when you're younger and you're doing things and you have more time to go to the gym, first of all, your metabolic rate is linked to the amount of muscle you have. And so as you get older, you're sat on your arse, you eat a bit more. We don't eat less, we eat more. And we can buy richer food because we got more money.

Metabolically, the most active part of your body are the muscles. So when you're younger and you're doing things and you have more time to go to the gym, first of all, your metabolic rate is linked to the amount of muscle you have. And so as you get older, you're sat on your arse, you eat a bit more. We don't eat less, we eat more. And we can buy richer food because we got more money.