Can Jamie Oliver’s sugar tax solve the obesity crisis? It can’t, and it’s over-simplistic, say dietary experts

It was a bombastic performance, grabbing the attention of MPs and garnering the headlines he was after – Jamie Oliver’s “let’s get medieval” on sugar’s ass. But as the celebrity chef took to the House of Commons to lecture on the evils of refined sugar and the need for a tax on soft drinks to combat obesity, you could be forgiven for thinking all right-minded health professionals would be behind him.

But are his claims justified? According to some of the UK’s most respected diet experts, the answer is “not really”.

They say demonising the ‘white stuff’ is not the solution to the problem of our ever-expanding waistlines.

Not only does isolating sugar ignore a host of other factors but it adds to already widespread confusion over what causes obesity – and what sugar is.

The sugar-free gurus, for instance, preaching the exchange of Tate & Lyle for the exotic likes of maple syrup, dates, coconut sugar and molasses are piling just as much sugar into their ‘virtuous’ middle-class treats as they would if they bust open a pack of Wagon Wheels and wrapped them in fancy ribbon.

Sugar and obesity: an oversimplification

“Yes, a high calorie diet does increase the risk of putting on weight,” says Catherine Collins, principal dietitian at St George’s Hospital, London and manager of dietetic services for diabetes and cancer. “But at the moment the research does not support that this is all due to sugary drinks and sugar.”

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While Collins is happy to advise ditching sugar-sweetened drinks from our diets she insists that vilifying them alone is not helpful.

“People do not eat in a vacuum, and all the modelling from the likes of [campaign group] Action on Sugar and others makes a common mistake: if you cut ‘x’ from your diet you reduce ‘y’ number of calories and reduce obesity. It’s not true.

“If you don’t buy a sugary drink, what do you buy instead? A can of diet Coke and a packet of crisps? That’s one of the problems with adding taxes to sugar alone.”

What happens when sugary drinks cost more

Many proponents of the soft drinks tax cite Mexico as an example of where the initiative has succeeded. A ten per cent levy on sugared beverages there led, after six months, to a reduction in sugared drink consumption of six per cent, and after one year to an average drop of 12 per cent. Among low-income groups that drop was around 17 per cent.

But Collins insists: “They are saying it’s a success in getting people not to buy sugary drinks because the price stops people dead at the till. But will it stop people getting overweight? At the moment the answer is we don’t know.”

Putting a price premium on soft drinks, she adds, may push consumers to buy more of something else instead. A 2014 European Commission study on food taxes found: “Consumers may instead purchase similar non-taxed or less heavily taxed items… cheaper brands of the taxed products [or] other products with similar levels of sugar, salt or fat to those that are taxed.”

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And an Institute of Economic Affairs report this summer, Sweet Truth, concluded that a sugar tax would “do little to deter individuals from buying unhealthy items but low-income households that pay a higher proportion of their income on food and drink would be hit particularly hard”.

Teens’ sugar consumption

Meanwhile, the most recent National Diet and Nutrition Survey shows that among teens, 16 per cent of their calorie intake comes from ‘free sugars’, generally due to soft drinks, fruit juice, biscuits and confectionery. That leaves 84 per cent of calorie intake coming from elsewhere.

In adulthood that figure drops to 12 per cent and is largely due to table sugar, jams, marmalades, alcohol and confectionery as well as soft drinks. The calorific value of alcohol, at seven calories a gram, exceeds that of sugar, at four calories a gram.

As adults, adds Collins, “we tend to favour umami foods over sweet choices so cheese, for instance, is maybe a bigger aspect of excess calories for us than sugary drinks”.

Some experts suggest a sugar tax on soft drinks would result in an average reduction per capita of just one gram of sugar per day – around four to six calories.

Smarter ways to improve nation’s diet

So what is the answer? Not a one-off sugar tax, argues Dr Duane Mellor, assistant professor in dietetics at the University of Nottingham.

“Identifying one thing as the culprit in the diet is where this is going wrong… One could reflect on the problems we have encountered from going low-fat. [Pinpointing sugar is] too simple; excess energy intake is the reason. Yes sugar is easy to over-consume but it’s wrong to demonise one food. It’s whole dietary patterns that count. There is limited data suggesting causality.”

Instead, Dr Mellor backs a whole diet approach: “Eat fewer processed foods; these tend to be higher in fat, salt and sugar for a start.”

A smarter and more challenging approach, he says, might be to tax ingredients in the supply chain, pushing manufacturers to reformulate their products with less fat, sugar and salt.

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Dr Alison Tedstone, director of diet and obesity at Public Health England, says the organisation “would rank three other interventions above a tax”, clamping down on price promotions, the advertising of unhealthy foods to kids and reducing the sugar content of the food we buy in supermarkets, cafés and restaurants generally.

Evidence for ‘healthier’ sugars

Confusion over what we should eat is only increased, say experts, by the rise in wellness bloggers and self-styled nutrition experts calling for sugar to be damned.

Is there any evidence to suggest that the coconut sugars, molasses and maple beloved by these sugar-free diet advocates are in any way better for us?

Dr Mellor says: “None. These are still sugar.”

And Collins adds: “At the point of absorption in our bloodstream the body sees all sugar as the same.”

The only “interesting” alternatives are stevia and xylitol, though xylitol may have laxative effects and more research is needed on stevia.

In truth, the best way to tackle the obesity crisis is to encourage the archetypal Mediterranean diet; boring, maybe, but backed by evidence. Enjoy sweet treats in moderation.

Collins concludes: “Anyone that gives a food a health halo or vilifies another, it’s a sign that that person has a very limited understanding of what constitutes a healthy diet.”