What you don’t realise about the strange new advice on sugar

‘Like putting Dracula in charge of a blood bank’ is how Action on Sugar’s Simon Capewell described Ian MacDonald’s role as chairman of the Scientific Advisory Committee on Nutrition (SACN) last year. Professor MacDonald’s reputation as one of Britain’s leading nutritionists gave him no protection when Channel 4’s Dispatches programme devoted half an hour to attacking any scientist who receives grant funding from the food industry. Seemingly unaware that industry-government partnerships are the norm in diet research, Action on Sugar’s Aseem Malhotra accused MacDonald of being ‘in bed with the food industry’ and called for his resignation. Similar inferences and accusations were made in a British Medical Journal ‘investigation’ earlier this year.

We shall probably never know whether this smear campaign had any influence on the conclusions of the SACN report when it was released last week, but the campaigners certainly got what they wanted when MacDonald et al halved the recommended sugar intake from 10 per cent of daily calories to five per cent. A lower limit has been the holy grail for the anti-sugar movement for years (for reasons I recently discussed). The World Health Organisation let them down earlier this year when it kept the limit at ten per cent, but SACN played ball and the talk of Dracula and blood banks was conspicuous by its absence on Friday morning.

The pool of nutritional epidemiology is murky at the best of times, leading some academics to dismiss the whole field as pseudoscience, but if you are prepared to give it the benefit of the doubt, the SACN report provides a decent summary of the evidence to date. Taken together, it does not make happy reading for the anti-sugar/low-carb movement. SACN found an association, based on ‘moderate evidence’, between sugary drinks and type 2 diabetes, but it failed to support any of the other pet theories of the anti-sugar campaigners. For example, it found ‘no association’ between sugar and type 2 diabetes, ‘no association’ between sugar and blood insulin, and ‘no association’ between sugary drinks and childhood obesity. It also found no association between fructose (the bête noire of the anti-sugar lobby) and type 2 diabetes. As for the low-carb diet, SACN found ‘no association between total carbohydrate intake and body mass index or body fatness’, nor with type 2 diabetes or cardiovascular disease. By contrast, it found ‘some evidence that an energy restricted, higher carbohydrate, lower fat diet may be an effective strategy for reducing body mass index and body weight.’

You need to reach page 183 to find the only part of the 370-page report that made the headlines. SACN explained its decision to recommend reducing sugar consumption to five per cent of daily energy as follows:
‘To quantify the dietary recommendation for sugars, advice from the Calorie Reduction Expert Group was considered. It was estimated that a 418 kJ/person/day (100kcal/person/day) reduction in energy intake of the population would address energy imbalance and lead to a moderate degree of weight loss in the majority of individuals (Calorie Reduction Expert Group, 2011) … To achieve an average reduction in energy intakes of 418 kJ (100kcal/person/day) using this estimated effect size, intake of free sugars would need to be reduced by approximately five per cent of total dietary energy (418kJ/78kJ= 5.4) … A five percentage point reduction in energy from the current dietary recommendation for sugars would mean that the population average of free sugars should not exceed five per cent of total dietary energy.’

In other words, the average person consumes too many calories and if sugar consumption was reduced from 10 per cent of energy to five per cent of energy, people would eat 100 fewer calories (unless, of course, they compensated by eating more calories from other sources). This is the sole justification in the SACN report for changing the guidance on sugar. The mathematics is correct – 100 calories is roughly five per cent of an adult’s recommended intake. The logic is not wrong, it is merely trivial. If the aim of dietary advice is to get people to eat 100 fewer calories a day, similar edicts could be announced about any ingredient or food. Telling people to eat 25 fewer grammes of cheese a day would serve exactly the same purpose, but it would not tell us how much cheese it is safe to eat.

There is no difference whatsoever between saying ‘eat 100 fewer calories’ and ‘reduce your sugar consumption from 14 teaspoons a day to 7 teaspoons’. The latter, which has now been enshrined in official guidance, is merely one way of achieving the former. It is doubtful that even one person in 100 who saw last week’s headlines realises this. It is much more likely that they think scientists have found new evidence showing that consuming more than seven teaspoons a day is inherently dangerous, even toxic.

The clear implication from the new daily ‘allowance’ is that it represents the upper limit of a risk threshold, above which it is dangerous to stray. This is not what the SACN report says, and it is not their justification for changing their guidance, but it will be portrayed as the ‘safe limit’ by pressure groups forever more.

  • lolexplosm

    I had a quick look through the report and was surprised to see the same things that’s been mentioned i.e. Things anti-sugar campaigners won’t be mentioning again. Ever.

    My only gripe is the sugar sweetened beverages. They always seem to be based on American studies, which shouldn’t really matter since HFCS is essentially the same as sugar but fructose was mentioned in an annex because of the UK’s low fructose consumption, and calories and weight never seem to be corrected properly or I have yet to see a study on healthy weight individuals that consume these as part of calorie controlled diet. Now when you have 2 or 3 a day you start to struggle with getting proper nutrition and maintaining calorie balance so can we truly state that sugary beverages are a risk factor? Is it not confounding with increased calories and the weight those extra calories bring? Remember this same report has just stated sugar is not associated with any of the other usual sugar tropes such as type 2 diabetes, insulin, body weight etc so what’s so different about a can of soft drink?

    I think it’s worth mentioning a banana has the same GI and GL index as a small glass of coke.

    I honestly wish this would eliminate the low carb dogma and fat sanctification that’s plaguing the Internet and public minds at the moment. In particular the fructose rubbish and Lustig’s “theories”. Most people have now heard of the 5-10% sugar limit recommended by the WHO but are unaware this is mainly based on reducing dental problems and even then the evidence for a recommendation is limited. Nothing to do with diabetes etc.

    • Callipygian

      Lustig is an extremist on sugar — I would say, a demagogue on that subject, since it helps sell books — but behind the hyperbole lurks a truth, and I don’t think the SACN report is worth a hill of beans. It is contradicted by several decades of research, never mind much older studies that were thrown out by Ancel Keys and followers for no good reason, and it is contradicted by the the fact that for the past four decades the public has got fat following the sugar-is-fine-enough, low-fat-is good, carbs-are-wonderful advice. The people have also become very unhealthy and the ‘diseases of civilization’ are more rife than ever. Telling pre-diabetic people that sugar has no impact on insulin is tantamount to stabbing them in the front.

  • Bernard Tedowl

    Let’s quote what they actually said perhaps?

    Professor Ian Macdonald, chair of the SACN Carbohydrates and Health working
    group, said:
    “The evidence is stark – too much sugar is harmful to health and we all need to cut back.
    The clear and consistent link between a high-sugar diet and conditions like obesity and type
    2 diabetes is the wake-up call we need to rethink our diet.
    “Cut down on sugars, increase fibre and we’ll all have a better chance of living longer,
    healthier lives.”

    Not exactly pro-sugar? Pretty explicit link to type 2 diabetes?

    The poverty of the journalism in this article is embarrassingly poor,