Fat or sugar - what is worse?

Giles Yeo answers this one...

Giles -  Look, I think the answer is obviously too much of either. I mean, for sure in the 70s people were going 'low fat, low fat, low fat', you know, 'fat is a demon'. And so low fat foods come out. But the problem is fat tastes fabulous in food. And so when you remove it, you have to add something back, and then people then piled it in was sugar, and now people think that sugar is the new cocaine.

Chris - Do they really think that, Giles, or did you just speculate?

Giles - They do. When people, you know, they show a white powder. If you look at the imagery, if you look at the imagery in certain sectors of the food industry or the food gurus, the imagery, looks as if you know, someone is about to snort something. So no, I'm not, it's not hyperbole. People do think it's the next cocaine. But I think something important to consider, sugar is our base fuel. We need it and we need fat in order to survive. And so clearly we're eating too much of both. But what's interesting is fat, per se, is quite unpalatable. We don't eat butter by itself. Sugar itself is relatively unpalatable. Everything bad for you is a mix of sugar and fat. Oh my goodness. You know, pastry, chocolate, and and I think that's probably part of it, where a lot of the foods that we actually are eating today are high in sugar and fat. In nature, naturally, the closest thing we get to that mix of sugar and fat is milk, it's breast milk. So you know, clearly as a little baby we would have really enjoyed it. But out there, you know, very, very little sugar and fat and mix together.

Chris - Do you think that's part of it then? Do you think that's why we are so fond of that combo? It's to make sure that we get adequate nutrition when we're breastfeeding?

Giles - Probably. And I think it's probably one of these things where it's a hard-wired, primitive drive to eat that specific mix of products. And if you actually literally, if go and think about it, everything, or the vast majority of things that are really delicious to eat are a mix of fat and carbs.

Chris - You started by saying in the 1970s we demonized fat. I've got two questions off the back of that, then. One is, why did we reach the conclusion fat is bad? And do you think, then, that we have, by demonizing fat and pushing everyone towards putting sugar into things instead of fat, we've actually triggered the present obesity situation we have?

Giles - That's an interesting question. I think people, some people have argued that. I think the present obesity situation is too much food in general, period. It just so happens that foods that are high in sugar is very, very easily preserved. And so, you know, a lot of the ultra processed foods that are actually out there are going to be high in sugar and probably high in fat as well, and salt actually, in order to make it taste nice after they've been, you know, put through the ringer. So, I don't think is any one thing, per se. It clearly had a driving role. The question of course, as well is, what kind of fat we're talking about? We're talking saturated fats, okay. Unsaturated fats? And so not all fats are equal. So, I think demonizing the entire load of fat, has clearly been a silly thing to do.

Chris - How did they reach that conclusion? Fat equals bad.

Giles - I think when you actually looked at it, well, clearly if you actually had too much fat and at the time when you eating fat, you're eating lard, you're eating animal-based fats, you're eating saturated fats, you know when you went, chips were actually all fried and animal-based fats. Whereas as we began to actually go through and understand, hang on a second then there are unsaturated fats, there's olive oil, olive oil is actually not so bad for you, actually it's quite good for you, and then people began to have a more nuanced view of fat. But I think in the seventies, people probably thought that, 'Oh, you know, when we're talking about fat, we're talking about butter, we're talking about lard', and that's probably it. And that, at high amounts for many people, not good for your cardiovascular system.

Chris -  But that is what the Atkins diet is founded on, isn't it? A high saturated fat intake, substituting those fats as calories for carbohydrates. So has that therefore translated into slimmer people with a higher risk of heart disease, then?

Giles -  Actually, the Atkins diet is more a high protein diet than it is necessarily a high fat diet.

Chris - But you can't get one without the other.

Giles -  That is very true. I mean now you're not, I think there is a very dangerous line and there are certain cardiologists out there and I'm not not the one sitting in this room who argue that, you know, we can eat as much fat as possible. Okay. That, that really, it's all about fat. Eat as much fat, the fat is not going to be bad for you. And I think that's a dangerous line. I think there are people whose dietary-related, you know, lipids and cholesterol are not sensitive to diets and so they can probably eat a whole stick of butter. But for the vast majority of us, I think eating too much saturated fats is not a great idea.

Chris -  James?

James -  Yeah, I completely agree with Giles. I think a balanced diet is the way forward. These extremes, either extreme carbs, extreme fats, extreme protein I don't think is healthy.

Chris -  Have you had patients who subscribed to Atkins-type diets in order to lose weight because they're told, 'Oh, you're overweight, that's bad for your health'. So they then substitute with one of these diets and end up paradoxically making themselves slimmer but in worse health?

James - Certainly, it works. I have had patients who have lost significant amounts of weight on this kind of diet. Their lipid profile, so the cholesterol in their blood, seems to change often in not a very good way, so the protective cholesterol seems to go down, the bad cholesterol, we call it the LDL, seems to go up. There are longterm dietary studies going on where we're studying the effects of things like the Mediterranean diet, the Atkins diet, and many, many other ones that are out there. But I don't think the studies have been going long enough to tell us whether it actually increases or decreases your risk of heart attack and stroke.