 OK. So, let's look at how we're going to get rid of that fat or protect ourselves from ever getting that fat, which looks like a more relevant thing for an audience like you. So, here's what we generally believe about weight control. It's based on calories going into and coming out of the body. So calories come out of the body through metabolism and also through exercise. Felly, chi oedd yn golygon gweithio bwysig fadeb oed y dyfodol y dyfodol, byddwn yn swydd staff. Aquestio bwysig yn sefyddiol iawn o ddoll. Felly, ond, wnaeth eto bwysig gweithio'r fflwfr, wedi bod yn gwneud o'r wdarlanol ar gyfer y amlŽb, yn gweithio'r f préc lle oedol, wrth gofym mwy ojo, oedd wedi gwneud fydd ydy'r bwysig. Rwy'n g荔wyd 3500 chwymod y ffap. Felly, mae'n gweithio'r ffap yn 500 chwymod of deficit each day and you can do that either with diet or exercise or both. Then over the course of a week you're going to have accumulated an overall deficit of about 3,500 calories which is about the same amount of calories that you find in a pound of fat. So that is the calorie principle in a nutshell but there's one fundamental problem with it. What? Anyone? Carries out does vary? Anything else? Yeah, yeah that's true that is another problem with it but here's the fundamental issue with it as I see it okay and this is quite common okay. It doesn't work. Let me let me just caveat this a little bit. It does work in the short term. If an individual who normally eats 2,000 calories eats 1,000 calories a day over the course of a few days assuming everything else is the same they almost certainly will lose weight and they may lose weight for several days or weeks or even months but we have a wealth of experience now and also a ton of scientific evidence that shows that when individuals take a calorie-based approach whether that is eating less and or exercising more it hardly ever leads to significant or sustained weight loss. It hardly ever works. Here's a little bit of evidence in this area. These are all studies basically long-term studies where they've they've done something fairly dramatic for relatively extended periods of time so the interventions basically in these studies were either diet or diet and exercise. Now these diets are usually low fat carbohydrate rich calorie controlled diets okay. These are quite difficult to stick to by the way but they're fairly intense as an intervention and then on top of that many of these people in these studies have been doing I don't know 30 45 minutes of exercise three four five times a week. That's a fair amount of exercise. It may not be much to you but to mere mortals okay. That's quite a lot of exercise but just have a look at this study here third down. This is the result of people doing that for two years okay. Average weight loss with just diet was about two kilograms okay so I don't know four and a half pounds and here with exercise added on top it was two and a half kilograms which is what about five and a half pounds okay. Now you might say well that's better than nothing because if you were five pounds overweight and you got down to your fighting weight fantastic but actually in these studies the average weight of these individuals was about 16 and a half stones okay so that's quite heavy. So if you've spent two years starving yourself and exercising yourself into oblivion and at the end of it you've lost just a few pounds in weight you would generally regard that I would suspect as not a great return on investment. It doesn't really work but here's the other thing. I've worked in practice as a doctor for over 20 years now and I've realised over the time it doesn't work because time and time again we see individuals who have failed to be able to successfully apply the calorie principle. So what's wrong? Well there's a general assumption that the calorie principle must work. It must work okay because it's simple mathematics it's simple physiology or metabolism okay. So in other words if people are not losing weight successfully in the long term using this approach there's something wrong with them. Now either they've been a bit greedy or a bit lazy you know they just haven't applied this enough okay. They don't have enough self-control and they lack they have a weak will they've got an inadequate personality I don't know all these thoughts and often these judgments by the way are quite self-applied so over the years I've seen many individuals who assume because the calorie principle has not worked for them that there must be something wrong with them but let me just tell you it fails so consistently I mean practically no one can make this work for them in the long term you might say maybe there's a problem with the principle maybe the issue isn't really that people fail to apply it correctly in a lazy and weak or whatever it's maybe that the calorie principle is somehow flawed so I'm going to spend a little bit of time talking to you about what it is about the calorie principle the cause is people to be trapped in cycles of weight loss and then weight gain and then needing to repeat that cycle with more weight loss and weight gain okay. Some of you may have possibly flirted with this yourselves okay many individuals will flirt with it once they get a bit older once they get as old as I am middle age basically people very often are now caught in cycles of weight loss and weight gain so in a way a lot of this information might be appropriate to you now but it might not it might be appropriate to you in the future so if you think about weight control in a slightly different way what it might enable you to do is future proof yourself from these problems so that you don't turn into your dad so why do calorie based approaches not work okay I'm going to go through a range of reasons why calorie based approaches can't really work okay and I'm going to start with this it's really this concept okay if you have a certain amount of metabolism burning I don't know 2000 calories a day if you only give the body say 1500 calories the inevitable consequence of that is that the body is going to burn less fuel it's like a fire and taking a calorie based approach is like putting less fuel on the fire so you would not expect the metabolism to burn quite as well as a result of that now we know from science that when the body is put in this situation it brings into play a number of mechanisms that put a significant dent in the metabolism okay and there's certain changes in the body that can be monitored around we'll explore some of this in a little bit more depth later but thyroid hormone levels thyroid is a very important organ that produces hormones that stimulate the metabolism so you get changes in these hormones you get changes in the levels of a hormone called leptin which I'll tell you about later and also both in animals and in humans when you put them on calorie restricted diets they move less they spontaneously move less they become less active this is all an attempt by the body to stop you starving yourself to death it's a normal sort of mechanism but it can make things very difficult because often people will find after some brisk initial weight loss that their weight loss slows to a crawl and will plateau at a weight way above the weight that they wanted to get to that's a very common thing that we see in practice so once you've plateaued here you're a bit hungrier you're a bit tired from your exercise and you're not getting anywhere and you know you've gone down I don't know from 13 half to 12 and a half stone but your idle weights 11 or something and you get fed up and you will often default back to your original diet not surprisingly very often though now you've put a big dent in your metabolism that weight will return very quickly it often returns alarmingly quickly and people will often end up at a weight above the weight that they started with and this is just one mechanism okay by which the body can scupper your attempts at weight loss it's very difficult to starve the body into submission essentially now this was studied a long long time ago okay back in the 1940s after the second world war a lot of people had starved as a result of the second world war and some American scientists were interested in what you can do to refeed people and get them to put their weight on healthily so they took a group of men and they first of all what they call semi-starved them by giving them 1600 calories worth of food in the form of a high carbohydrate low fat diet for 24 weeks okay now actually these men lost a significant amount of weight they lost in total an average of around 20 to 26 percent of their body weight okay however overall the amount of energy that they expended through metabolism and spontaneous activity went down by almost 40 percent so you'd expect people to have low metabolism as they lose weight they're smaller right but actually the overall effect was far exceeded what you'd anticipate just as a result of weight loss and so they here's a picture of a couple of people that were in that experiment and this is what happened to them and then after that basically they started to feed them again which i'll talk about in a moment but i just want to make you aware of this these individuals were eating a fair number of calories right 1600 calories is not a small amount of calories it wouldn't be what i would recommend necessarily but it's not like they're eating 800 or 500 calories that's a fair amount many many diets okay based on the calorie principle will recommend that sort of order of magnitude to people often 1500 for women 1800 or so for men right but the effect of eating in that way on these men was utterly profound first of all they were perpetually hungry perpetually hungry but not just that they lost interest in practically every aspect of life so the libido went any ambition went personal relationships went okay all of this okay is well documented and they also became cold they couldn't think straight they became obsessive about food all they could think about was food and they were for would for example two gum and drink coffee incessantly okay and this is all on 1600 calories a day which is a fair amount of calories all right so one of the fundamental problems that we have here is that dieting if you want to use that term makes people hungry and as i'll explain a more depth later using a relatively high carbohydrate low fat approach makes people particularly hungry and one of the reasons for that is that carbohydrate is quite disruptive for levels of blood sugar which i'm going to explore in some depth a bit later on okay now when you have disruption in blood sugar you can drop your blood sugar and that can cause people to be hungrier than they should be it can cause food cravings and it can cause that mid to late afternoon lull that i mentioned earlier that causes people to need to jab themselves in the leg with a sharpen pencil okay so in the first part of this presentation we're going to be talking mainly about these and how to get out of this trap if you've ever fallen into it okay and then the second half of the presentation we're going to be talking more about the influence of food and nutrition and also exercise on general health feeling good being able to concentrate well and being optimally effective now after starving these men they started to feed them okay and at one point they gave them unlimited amounts of food so they could eat as much as they like now in response to that some of them were consuming up to 4 000 calories a day okay and it seemed that their eating had a direct relationship to their fat stores in their body so in other words as fat stores in the body were replenished they ate less but by the time they were eating what you might call normally right these men had fat levels that were 75 percent higher than they were at the beginning of the diet now for 60 years now we've known that applying a calorie based low fat high carbohydrate approach to weight loss has very detrimental effect on the body has detrimental effect on physical and emotional well-being and it generally leads people to be fatter at the end of it all than they would have been if they'd done nothing and yet this is an approach that often underpins health professionals advice to people you need to eat less calories okay and you need to make the diet low in fat that's a common refrain but there's other problems associated with dieting okay here's another one when people are counting calories and reducing calories it raises levels overall of a of a hormone called cortisol cortisol is your main stress hormone now we need cortisol it's absolutely critical to life but too much cortisol actually predisposes to fat deposition but particularly around the middle of the body which is the form of fat most strongly associated with health issues like diabetes and heart disease here's another thing our metabolism depends on nutrients lots of different nutrients you know magnesium b vitamins or whatever okay if we eat a calorie reduced somewhat inadequate diet we may become a bit low on those nutrients and that may stifle the metabolism okay and we have at least some evidence this was a study actually done in women that when they induced weight loss in people through through these women in with a diet okay just supplementing them with a multivitamin and minerals significantly improved their weight loss which provides at least some indirect evidence for this idea that if we don't provide enough in the way of nutrients into the body it's going to be difficult for the body to metabolize food fully and lose fat