They are both bad, but which is worse? Fat or Sugar? A couple of twins who are both doctors investigated by eating just one or the other for a month.
This is obviously not a proper scientific trial as they pointed out themselves early on in the programme. But it was fascinating nonetheless to watch the effects. The twin on the sugar seemed to be doing a lot better. He was more alert and was able to cope with exercise a lot more. He moaned about how boring his food was. The other twin also quickly fell out of love with a diet that allowed him bacon, eggs and steak but no bread. But he also found his mind and his body both reacted against the diet as well. He was sluggish physically and mentally.
Nobody lives on a diet like these of course and only silly people even advocate them. But it was interesting to see the final outcome. I thought that I was reasonably well informed on this kind of thing but the results surprised me, as they did the guys on the trial. The high sugar diet did not seem to have produced much in the way of ill effects. I wasn’t expecting short term problems but I did think a diet like that would lead to elevated blood sugar levels and increased weight. In fact he lost a little weight and his insulin levels simply rose to cope with the higher amount of sugar he was eating. It was no surprise that the fat only diet led to weight loss – it was pretty similar to the Atkins Diet from a few years back. The surprise, to me at any rate, was that fat only diet was the one that gave the blood sugar problem. In fact it was on the brink of getting to full out diabetes. The nutritionist instructed the twin to stop the diet immediately.
Both these diets are unhealthy, unnatural and almost impossible to stick to so in a sense the whole thing was a pointless exercise. But I felt I had learnt something from them, if only just how little I know about the way the body really copes. But the really interesting bit came at the end of the show. It is usually a mistake to second guess, but I got the feeling that it was the nugget at the end that was the real point. Horizon is a long programme and there simply wasn’t enough to say about the last bit so the fat versus sugar thing was basically filler – albeit rather good filler.
Because the question then turned to what happens when you have both fat and sugar in your diet. It turns out that lab rats given access to unlimited sugar on top of a normal rat diet will eat the sugar. But they carry on eating their regular food as well, simply compensating for the extra calories from the sugar by cutting down a bit on what they eat. So they put on very little weight. They do the same when offered unlimited supplies of fat. Again they substitute a bit but basically carry on as usual. But give them 50:50 fat and sugar combined and they start eating a lot more than usual. They abandon their regular food and tuck into way more calories than they would eat normally. The source they used for this was cheesecake, as it happens. There was a shot of a lab rat tucking into a portion, and he certainly looked like he was enjoying it.
What happens in rodents doesn’t always happen in man, but they did an experiment which showed that in this case we are much like rats. Donuts with different ratios of fat to sugar were offered to people on the streets of New York and London. The most popular choice was the 50:50 one. In fact it is obvious really. Nobody eats pure sugar. Nobody eats butter on its own. Put them together in the form of a cake and nobody can resist. Nature has equipped us with an incredibly sophisticated machinery for seeking out the tasty ratio while at the same time failing to give us much in the way of willpower to overcome it.
So what have we learned? Extreme diets are a bad move. But it is easy to underestimate how well our body can cope. This trial demonstrated that we can at least survive for a while without sugar and carbohydrates, and can actually function pretty well on nothing but sugar. The thing that we can’t cope with is the sheer pleasure of the combination of fat and sugar. Even here it doesn’t look like a little bit of indulgence can do much harm. But over time the excess of calories over what we need will put on the pounds. It looks like the best, if boring advice, is simple. Don’t go on an extreme diet. Just try to cut down the pastries, chocolates basically anything else that is really delicious. I think we already knew this really.