For four decades we’ve been led to believe that fat is the ultimate food enemy, but we’ve been fed a lie: the real danger is sweet, addictive – and found in almost everything we eat.
Food and Behaviour Research is proud to have hosted Professor Robert Lustig's visit to the UK in March 2013 and to the events we ran in London and Oxford with Prof Lustig as our keynote speaker. We were also delighted that Professor Michael Yudkin, son of John Yudkin, accepted our invitiation to take part and update us on his late father's legacy. Please see:
o what do you know about eating and getting fat? If you’re the average British person then it’s probably something along these lines: eating too much fat will make me obese, clog up my arteries and lead to a heart attack, so I should follow a low-fat diet and eat lots of fruit and vegetables.
Wrong. While you were busy fretting over your saturated fats and dietary cholesterols, there was a far more potent food nasty lurking in your kitchen: sugar. The amount of sugar we eat is now being blamed not just for the obesity epidemic but for heart disease, type 2 diabetes and soaring cancer rates. It’s not just the excess calories we’re consuming; the problem lies in the way we metabolise sugar.
‘We have been sold an absolute lie about food and health,’ says Zoë Harcombe, nutritionist and author of The Obesity Epidemic. ‘It has been put about since the 1970s that fat was the bad guy, yet the only fats we know to be harmful are trans fats, and these are almost exclusively man-made. If the fat occurs naturally then it’s fine – no exceptions. Sugar, on the other hand, when added to food, is almost uniformly bad.’
So why was this information hidden from us? ‘Because,’ says Harcombe, ‘the commercial food producers, who rely on sugar, represent a huge and powerful lobby. It’s not just the obvious brands, such as fizzy drinks manufacturers, that would suffer if sugar were removed from our diets. Sugar is added to just about everything you buy ready-made: bread, sauces, ready meals, drinks, tinned foods… The list is endless.’ Even baked beans can contain two and a half teaspoons of sugar in just half a tin. Furthermore, say campaigners, the low-fat industry (now worth billions) is absolutely reliant on sugar because the only way to stop low-fat food tasting like cardboard is to replace fat with sugar.
Robert Lustig MD is a paediatric endocrinologist and childhood obesity expert at the University of California and one of the most vocal of the anti-sugar campaigners. Lustig’s 90-minute lecture ‘Sugar: The Bitter Truth’ (viewed over four million times on YouTube) is uncompromising in its condemnation of sugar as the cause of the obesity epidemic and its assertion that governments (under pressure from powerful food producers) have kept this fact hidden.
Lustig makes the point that we have been trying the low-fat approach for 40 years and it has failed to make us slimmer. In fact we’ve got fatter – and sicker (six per cent of adults in the UK are now registered diabetic).
While the percentage of our daily calorie intake accounted for by fat has dropped steadily, the incidence of obesity and related illnesses, including type 2 diabetes, has rocketed. ‘Sugar is the problem,’ states Lustig, ‘and yet public health officials are still advising us to follow a low-fat diet. It’s Albert Einstein’s definition of insanity – doing the same thing over and over again and expecting different results.’
It might all have been different if, 40 years ago, we had listened to John Yudkin, a British physiologist and nutritionist. His 1972 book Pure, White and Deadly argued that we were massively overeating sugar, which was not only making us fat, but also causing liver damage, heart disease and cancer. However, these beliefs earned him some powerful enemies in the sugar industry. In 1979 the World Sugar Research Organisation rubbished his work as ‘science fiction’, while the food industry got squarely behind the theory that saturated fat was the dietary devil.
Yudkin’s problem, adds Lustig, was that he could see the correlation between sugar and disease but couldn’t quite prove it. Fast forward to 2014 and the anti-sugar lobby now has science on its side. We now know, for example, that carbohydrate (of which sugar is the most dangerous form), not natural fats, is the driver of the type of ‘bad’ LDL cholesterol that leads to heart disease. And numerous studies have linked both overproduction of insulin (which stimulates cell growth) and obesity to increased risks of various cancers including that of the breast and liver.
What Lustig is gunning for in particular is fructose, a fruit sugar that makes up 50 per cent of the refined sugar found in virtually everything you buy pre-made. The problem with fructose is twofold. Firstly, there is no hormone to remove fructose from our bloodstream (unlike glucose, which stimulates insulin production).
It is therefore left to the liver to remove it and when the liver is overwhelmed it converts fructose to liver fat, which ups our chances of developing insulin resistance (a precursor to diabetes), hardened arteries and heart disease. Secondly, fructose suppresses the hormone leptin, which tells you when you’re full. In other words, your brain lets you consume it without limit.
It’s going to be hard to turn back the sugar clock, says Lustig. But a good place to start would be drinks, because it’s particularly bad to take on sugar in liquid form. ‘Think of it this way,’ says David Gillespie, an Australian lawyer, father of six and campaigning author of Sweet Poison. ‘If you sit your kids down in front of a fruit bowl they are only going to eat one orange, because an orange contains fibre, which makes you full. There is no problem there – my kids think of fruit as nature’s dessert. Now take out all the fibre by turning it into a juice and suddenly that child can consume way more than one orange in a sitting.’
The amount of fructose lurking in your juice carton also depends on whether the manufacturer has added extra sugar. However, to give an idea of why anti-sugar campaigners are so worried about fruit juice, 12fl oz of unsweetened apple juice contain nine teaspoons of sugar (36 grams) – even more than a can of cola, which has about eight and a quarter teaspoons.
Public health bodies are starting to listen. The World Health Organization (WHO) now says that sugar restrictions must be considered in order to stem the global ‘tidal wave’ of cancer. WHO is thought to be on the brink of revising its guidelines on manufacturer-added sugar (including the sugar from honey, syrups and fruit juices), down from ten per cent to five per cent of our daily calorie intake – this means around six teaspoons a day for women.
We can only guess what John Yudkin, who died in 1995, would have made of the wide acceptance of his ideas. His book Pure, White and Deadly is back in print – this time with an introduction by Robert Lustig. ‘I think he would have been pleased,’ says his biochemist son, Professor Michael Yudkin. ‘Not to say, “I told you so”, but because my father’s great passion was public health and he saw the world being harmed by something he thought was preventable.’
David Gillespie believes that we are on the brink of a public health revolution – similar to what’s happened with tobacco. ‘But this is not going to take anywhere near as long,’ he predicts. ‘The early anti-tobacco campaigners didn’t have the internet and social media. A few powerful people had a stranglehold on the data but that isn’t the case any more. In ten years’ time, parents are going to be looking back and saying, “Can you believe that they used to feed fruit juice to children?”’