Dealing with Diabesity

With obesity and diabetes rates rising around the world, we seek solutions...
25 April 2023
Presented by Chris Smith
Production by James Tytko, Rhys James.


Losing weight


With 14 million new cases of diabetes each year being attributed to poor diet and half the worlds' population estimated to be overweight or obese by 2035, it's no wonder the UK's Chief Medical Officer, Chris Whitty, claims the situation around these conditions presents one of 'the biggest future health challenges we face.' So why is it happening and what can be done to reverse these worrying trends? We find out what dieting does to your metabolism, and whether the effectivness of weight loss drugs in the short term might make them a part of the solution...

In this episode

A few burgers on a table

00:51 - 14 million with diet related type 2 diabetes

Each year, poor diet accounts for millions of new type 2 diabetes cases around the world

14 million with diet related type 2 diabetes
Meghan O'Hearn, Tufts University

Last week, a report published by Diabetes UK estimated that 5 million people are currently living with the condition in this country. 90% of diabetes cases are type 2, which is mainly lifestyle related and, you guessed it, obesity is one of the leading causes. And it’s not just here in the UK that this is a problem. A study has been published this week from Tufts University linking poor diet to 14 million cases of type 2 diabetes globally. To break down what all this means, Chris Smith spoke to first author on the paper, Meghan O’Hearn…

Meghan - Broadly, we're seeing this increase. In the context of obesity and overweight, poor diet is really one of the major drivers. And when I say poor diet, that means a lot of different things; it means low intake of healthy foods as well as high intake or excess intake of unhealthy foods. It's complicated because that can mean different things for different people but, at a population level, we're really seeing problems related to carbohydrate quality, so the types of grains that people are consuming, as well as excess intake of things like red and processed meats. These are two major areas that we see as primary dietary drivers of problems like obesity, as well as type 2 diabetes, which are very closely linked and related.

Chris - Who is affected, principally? Are there any groups that are particularly vulnerable or is this across the social scale and across the world economies?

Meghan - Obesity has increased to about 764 million adults and, similarly, with type 2 diabetes, an increase to about 500 million. This is really a global phenomenon. There is not a single nation around the world that has experienced a decline in either diabetes or obesity in the last 40 years. There are no countries that are untouched by this problem, although there are definitely disparities and inequities in terms of this health burden. We see that individuals from lower economic status, lower education tend to have the highest burden of these types of health issues.

Chris - Why do you think that is? Because people have always been poor and people have also always been poorly educated through not necessarily any fault of their own, through the effects of society, but those people weren't always poor and overweight. So what has changed?

Meghan - We've seen massive changes in the food environment that we live in, and I think that the food policies that we see, social safety nets, they're really designed to make sure people have sufficient calories, but not necessarily nutritious calories. So I think there's a policy side to it. And then I also think that there's a kind of a private sector, food environment side as well. We see that there's increased availability and desirability of unhealthy foods, ultra processed foods that are high in sugar, refined grains, saturated fat and salt that are really heavily marketed, particularly in low income populations, and they are, in some ways, addictive.

Chris - What are the consequences of this?

Meghan - At an individual level, it has a significant impact on people's risk for diet related diseases. Think diabetes, cardiovascular disease, also infectious diseases like Covid 19. But at a population level, it really has significant implications for a nation's overall stability, healthcare system capacity, and even economic productivity, both at a business level if all the workers, employees are unable to work and they have a lot of healthcare issues, that's going to have a significant financial burden on that business. But also on economic welfare and GDP and things like that.

Chris - Tell us about the study that you've just published on this.

Meghan - We recently published an analysis that looked at the primary dietary drivers of type 2 diabetes around the world. So we estimated the proportion or the percentage, as well as absolute number, of cases of diabetes in 184 different countries that are due to poor diet as well as low intake or insufficient intake of healthy foods. We did our modeling analysis in 1990 and 2018. In 2018, poor diet contributed to 14 million cases, which represents about 70% of the newly diagnosed type 2 diabetes cases globally.

Chris - Obesity is the biggest risk factor for diabetes. This is a massive health cost, isn't it? Looking at the figures for the United Kingdom's National Health Service, the cost of diabetes is measured in the billions every year.

Meghan - Absolutely. It's an enormous healthcare cost, but it also increases individuals' risk of developing other conditions like cardiovascular disease, renal decline, fatty liver disease, cancer. Diabetes is a healthcare burden in and of itself, but also is a very significant risk factor for these other conditions.

weight loss

07:01 - Low calorie diets can do more harm than good

Changes to our metabolism can mean that dieting ultimately results in overshooting your original weight...

Low calorie diets can do more harm than good
Andrew Jenkinson, University College London Hospital

Now that we've outlined the scale of the problem, we’re going to shift our focus to the reasons why a rising number of people seem to be struggling with their weight. Andrew Jenkinson is a bariatric surgeon - he conducts procedures to help patients lose weight when other interventions don’t work. He’s interested, though, in trying to get to the bottom of why it sometimes becomes necessary to take this drastic action at all. He argues that many of the diets his patients go on to try and gain control of their weight have a huge impact on their metabolism, which makes keeping the weight off very difficult. He also points to the changes in our hormones as further evidence as to why so many diets end in failure, and another piece of the puzzle is in our genetics, as James Tytko heard…

Andrew - There are many twin and adoption studies from lots of different countries looking at identical twins, brought up separately in different home environments. It doesn't matter whether they're brought up in a healthy home environment or an unhealthy food and play environment, all of them find around about a 70 to 75% concordance with their body mass index. So they may turn out to be slim, they may turn out to be obese. Just as you would expect them to have the same height and eye colour, they have very similar body mass indexes.

James - That's interesting. So has this genetic predisposition to high risk of obesity always been there and the modern world has just tapped into it?

Andrew - This is normal to the biology of any species. It's called heterogeneity. So this is like the differences between individuals of the same species. There will always be significant differences and that helps the species survive in times of environmental change. So, for instance, if there was a famine, people with genes that select for being able to be metabolically quite efficient and store more fat or energy on board, that section of the population are going to be more likely to survive.

James - So it's this in combination with those environmental factors which account for this epidemic of obesity that we're experiencing at the moment?

Andrew - You need to have a trigger for a chunk of the population. And we see about a quarter to a third of populations living in a western sort of lifestyle environment become morbidly obese. So they really struggle with their weight. Obviously they have a genetic predisposition, but also they have the trigger of the environmental factors that cause their body to want to store weight. You mentioned changes in the environment - we don't do as much activity anymore and we've got really tasty carb heavy, calorie heavy foods that are a bit addictive - that's a very, very simplistic way of looking at what causes obesity. It's not the calories in the food, it's what the food does to you metabolically, what signals it's sending you.

James - What are the factors which control how our metabolism can change, how it can store more energy or release more energy?

Andrew - The regulator of our weight is a hormone called leptin. The more fat cells we have, the higher the level of leptin in our bloodstream and it should act as a message to the weight control centre in the brain called the hypothalamus: "this is how much weight we've got on board." It's a little bit like a petrol gauge in your car. Various different factors in the environment, particularly insulin and some inflammatory factors, cause a blockage of that signal. So if you put on a lot of weight, your leptin levels should go up and your brain should actually sense that and it will then automatically decrease your appetite and increase your metabolism to maintain what it wants your weight to be: a normal weight. So, automatically you won't put even more weight on and you may even lose weight. However, if you are exposed to a Western diet where there's a lot of sugar and refined carbohydrates and also a lot of snacking between meals, your insulin level tends to be quite high throughout the day, much higher than if you ate two meals a day, not massively carb heavy. Leptin is blocked by the hormone insulin. So if we're brought up in an environment where the food gives you high levels of insulin all the time, that blocks that leptin signal. So the brain can't see the fact that you've got far too much fuel or fat on board. In fact, it's getting the opposite signal. And the analogy is, imagine if you're driving along the motorway and your petrol metre is flashing on red, you know you're empty, you'll want to get to the nearest petrol station. When you start filling up, you realise the car's already full. The problem is the petrol metre is broken. This is what leptin resistance is and this is what obesity is.

James - You've touched already on the way people try and control their weight, often unsuccessfully. Most people don't want to live in a way they know is not best for their health, they're going to try and do something about it, so they'll go on a diet. But why do many of the diets people embark on not work? What's the flaw which means they often end up being counterproductive?

Andrew - They go on the premise that obesity is caused by eating too many calories and not exercising enough - that simplified calories in, calories out equation. So they cut calories and they go to the gym, but the body will fight against that. As you lose weight, your brain will automatically go into calorie seeking behaviour. People who go on low calorie diets have extremely high appetites and they're having to use a lot of willpower. They do lose weight at first, but then you've got the other factor: your body can change your metabolism by about 700 kilocalories per day. This is just the energy you normally would expend even before you move. So heating your body, heartbeat, your breathing, your immune system, building or repairing the cells in your body. This is all your metabolism. That can be turned down so not only have you lost a little bit of weight on this low calorie diet and you're absolutely ravenously hungry, but after three or four weeks of being on 1,200 kilocalories a day, for instance, your body's adapted to that low calorie intake and you go on the scales and there's no change. You go to your GP and you say, "look, this diet isn't working anymore." The GP will not understand the fact that your metabolism can significantly decrease. Feeling like that and seeing the scales aren't shifting, they just come off the diet and say it's not working anymore. And then because their metabolism is so low and they're so hungry, they will regain the weight significantly and probably usually more. They end up heavier than when they went on the diet.

Couple holding hands

14:31 - Support is essential for keeping weight off

Family, friends or local groups can all play a part...

Support is essential for keeping weight off
Becky Johns & Dawn Sonnino, Slimming World

Lifestyle weight management services and weight loss support programmes play a crucial role in helping people to shed weight and help keep it off. Chris Smith was joined by Becky Johns and Dawn Sonnino from Slimming World...

Becky - I did a calorie reduced diet, tried my best to lose weight and found that I was really hungry all the time and really struggled to keep that momentum. I ended up yo-yoing all the time.

Chris - Dawn, is it very much about managing people's expectations of what a diet can do and over what sort of time? Because I think a lot of people are seduced by pictures of people in bikinis, beach ready, and they think "I want that." And they then launch into this very ambitious weight loss regime. And maybe they'll get there, but then they come home from their holiday and they're back to the environment that got them fat in the first place.

Dawn - Absolutely. So a lot of people will think they can come to Slimming World and within two weeks they'll lose all their weight. That's not going to happen. It's going to take a while and it's going to take a lot of changes. Once you've been on your holiday, then it's about coming back to group and getting back to starting the plan again and keeping it going. If you are only doing it for a certain amount of time, every year you're going to be rejoining. What we want you to do is stay with us.

Chris - So you don't, yo-yo.

Dawn - Yes. Get to understand the psychology, get to why you're doing what you're doing so we can change those habits. Once they're changed, then you're going to be successfully losing weight all the time until next year you are beach ready already. You haven't got to worry about losing it again.

Chris - Did you find yourself getting depressed, Becky, because a low calorie diet at the best of times makes you miserable.

Becky - It makes you very miserable. Yes, absolutely. And the bonus with Slimming World is the fact that not only are we encouraging you to eat the right foods and to make healthy habits for life, we also have what you call a body magic programme, which helps you with exercise as well. So that way you are getting all the endorphins going as well to keep you motivated and help you maintain that weight loss.

Do people relapse?

Dawn - Definitely.

Chris - Should they be prepared for that? I've spoken to people who do really well on a diet. They're very proud of themselves, but then they have a hiccup. Something happens in their life or something goes wrong. They put weight back on and then they think the world has caved in?

Dawn - I become very complacent. "I know what I'm doing, I'm going to be fine." And then old habits creep back in and, before you know it, you are yo-yoing, you are going up again. But at Slimming World we always encourage members to just stop the rot, just come straight back in. No embarrassment and there's no humiliation. We're just proud and happy to have you back in to get where you want you to be.

Chris - Everybody I've ever met and talked to who's into nutrition and diets and so on is usually like a stick insect. People who go to these sorts of help groups find this very intimidating because the people they meet are often what they would dream their ideal body to be like and they think, "well that's not me. What have I got in common with this person?" You are normally proportioned, but were you always normally proportioned, Becky?

Becky - I've lost three stone from Slimming World and have very happily managed to keep most of that off. When I first walked through the door, I was very, very worried about what I was going to find on the other side.

Chris - And what did you find?

Becky - A lovely, supportive group that was there to support me and it felt very much like a family. We're all there in the same boat. We all want everybody to do really well and it's getting that support from everybody each week.

Chris -  Have you had hiccups?

Becky - Absolutely. Ups and downs. Life gets in the way as we all know. It's finding the changes you need to make to make sure that you can get yourself back on plan and get yourself losing weight again if you need to.

Chris - And has that worked for you, Dawn?

Dawn - Yep, definitely. I was always thin as a child, right up until I was about 28 and then suddenly, due to ill health, ballooned in my weight.

Chris - And, if you don't mind me asking, how big did you get?

Dawn - I got to a size 22. I was about 14 and a half stone. But at the time, as it was happening, I was always assuming it wasn't that bad. Until I had to buy clothes for my brother's wedding, actually. And I was absolutely mortified at the size I had become. And when I stepped into Slimming World, I thought, obviously I'm going to be the biggest person in the room, everyone's going to be looking at me. And when I got there, there were all shapes and sizes. Nobody looked at me any differently. They just accepted me as a new member.

Chris - And what size are you now?

Dawn - I'm now size 14.

Chris - So that's a dramatic change, isn't it?

Dawn - I was just telling Becky, now I need to buy new trousers because they're all too big for me!

Chris - What has really worked for both of you, what is the recipe to that success that you've both got? You've both lost substantial amounts of weight and kept it off for the main part over a long term. What's been the key to that?

Becky - Going to group and staying to group. Because that is what's going to keep you going. It's that support you get from the whole group as well as your consultant. And they notice you if you're not there. Getting that motivation, getting that support, getting the recipe ideas and everything else that you get in group.

Syringe and needle for administering injections

20:12 - Weight loss drugs show some promise

But are they going to ensure keeping weight off long term...

Weight loss drugs show some promise
Adam Collins, University of Surrey

So what is the solution to losing weight and keeping it off? Diet and exercise, as we’ve heard, play some part. But many, including the National Institute for Health and Care Excellence or NICE, believe that the weight loss drug semaglutide, which is marketed as Ozempic and Wegovy, could be a game-changer in the fight to bring down levels of obesity. The drug, which is delivered via an injection into the skin, makes people feel full, so they eat less. But are drugs like Wegovy really a silver bullet? Chris Smith spoke with University of Surrey nutritionist Adam Collins...

Adam - Well, it's certainly very effective. It was originally designed as a treatment for type 2 diabetes, but as a side effect it got people to lose a lot of weight and hence it was rebranded as a weight loss drug. So it's definitely very effective.

Chris - How does it work?

Adam - It mimics a gut hormone that's released after you've eaten that makes you feel full. So it's an artificial version of that that you are injecting.

Chris - So when you are taking the agent, what are the side effects? Because some people have said that they are quite significant.

Adam - Yeah, I mean what you've heard, and some of this is anecdotal at the moment, but people's relationship with food really changes. It's so effective that actually people are almost repulsed by eating. They find it a real chore to eat because their appetite is so suppressed. And then the other effects that you get is, because you are obviously eating far less and you are losing weight relatively rapidly, that that can make you look very gaunt and physically your appearance might not actually be much better even though you have lost that weight.

Chris - People are saying that you go scrawny from the neck up, it's called Ozempic neck or something, isn't it? You get a very gaunt looking face?

Adam - That's right. And it's almost like a badge of honour. I think some people are saying because it's not a diet, it's a bit more masculine that you can go on these drugs and admit it and almost be proud of it rather than go on a diet to lose the weight.

Chris - You were just listening to what the two ladies were saying to me just now and much of the conversation dwelled on the fact that people yo-yo and they do relapse. And is this just a substitute for another diet plan and without the lifestyle modification that the two ladies were talking about to make sure you don't relapse, is there a real danger that when people come off this drug they're back to square one or worse just as they are with a diet?

Adam - Yes, absolutely. I think it is too early to see what effectiveness it has in the long run, but even the NICE guidelines are limiting it to two years. But certainly the fact that you are replacing what you would naturally produce after eating with this artificial drug means that when you stop taking it your appetite is going to come back with a vengeance. My prediction is that people are going to be ravenously hungry once they stop taking this drug. And like any other diet, if you don't have anything else in place to sustain that weight, then that weight's going to come back again.

Chris - I think I read somewhere that most people gain back a significant amount, three quarters of the weight they lose, within a year of stopping it?

Adam - Yeah. And I would say that that's probably an underestimate because what you tend to see in the scientific literature is the success stories. In reality, people are not only regaining that weight, but often overshooting their original weight. So it's almost like dieting is making them fatter. That yo-yo effect is almost like driving an increased need to diet even more, which is obviously not sustainable and in the long run it's going to make you metabolically worse.

Chris - It's not cheap either, is it?

Adam - It's certainly not cheap. I mean it's a very effective way of getting from A to B, but as your two guests before stressed, it's not about just losing the weight, it's about keeping that weight off. That's the real challenge. And that requires doing something that's sustainable and something that's going to be supported, whether that's support with a group or with your family and support network around you, and obviously incorporating other lifestyle changes ike exercise.

Chris - So what in your view does work? Do you think that this is just an of the moment thing and it will join the ranks of other interventions, but with flaws?

Adam - What I would say is the positive is that you've got a very effective tool to get people to lose weight. Now that is a challenge in itself, but in a way that's not the main challenge because the challenge is getting people to maintain that weight once they've lost it.


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