The rapidly rising price of chocolate may have a silver lining – it might tackle obesity

It was the most unseasonal news. The price of chocolate, already rising rapidly, is predicted to soar over the next five years, as a result of rising demand and falling production. If the forecasts are right, the Easter Bunny could become an endangered species – at least those of the foil-wrapped kind.

A supermarket price war drove down the cost of Easter eggs this year by an average of 10 per cent, according to The Grocer magazine. But the chocolate bonanza cannot last, experts say. The price of cocoa has jumped 50 per cent in the past two years and is expected to double by 2020.

Farmers who endure poor working conditions and receive rock-bottom prices in West Africa, the principal source of cocoa beans, are switching into more secure cash crops such as coffee and maize. The same pressures are driving young people from the rural areas to the cities, creating labour shortages on the plantations.

Meanwhile, the growing middle classes in Brazil, India and China are discovering a taste for chocolate, which is driving up sales. Soaring demand at a time of faltering supply is what lies behind the surge in price. The confectionery giant Mars forecasts a cocoa bean shortage of up to one million tonnes by 2020.

But could this coming cocoa famine have a silver lining? For decades the world has been seeking a solution to the obesity crisis. We have had years of arguments about sugar taxes, traffic-light labelling, curbs on marketing and advertising. Is it possible that market forces might help achieve the same end more simply and more effectively?

The UK is one of the largest consumers of chocolate in the world. We chomp our way through 10kgs per head of the stuff annually, a third more than France and more than twice the amount eaten in Italy or Spain. Just consider: a 65 gram Mars Bar contains almost 300 calories. Ten kilos of chocolate therefore adds up to an awful lot of energy which, if not burnt off, turns to fat and then sits on the hips or elsewhere on our bodies.

A decade ago the National Institute for Health and Care Excellence (Nice) spelt out how we should shrink our expanding waistlines. Not by going on a crash diet – they are ineffective (the weight quickly goes on again when the diet comes to an end) and can be harmful.

There was only one diet that worked, Nice said: eating less. Ideally, the diet should contain 600 fewer calories a day than is burnt in energy. That was the most likely to result in “sustainable weight loss”.

The average man burns 2,600 calories a day and the average woman 2,000 calories (more if you are doing heavy physical labour, less if you are slouching in front of the TV). In that context, 600 calories sounds like a lot. But it is in fact the equivalent of a Mars Bar (294 calories) and a Danish pastry (287 calories) plus a mug of tea (29 calories). By giving up that chocolate snack a person can get half way towards sustainable weight loss without cutting down at meal times at all.

This was brought home in 2011 when, in one of her first public pronouncements, Dame Sally Davies, England’s Chief Medical Officer, launched a campaign to cut five billion calories a day from the national diet. This we were told was equivalent to five Olympic-sized swimming pools of cola or a line of chocolate bars which would stretch from Land’s End to John o’Groats and back again.

It seemed a formidable challenge – who could cut their calories on such an industrial scale? Then it was pointed out that it was the equivalent of only 16 dry-roasted peanuts, per person, per day. Dame Sally might have had a better reception for her announcement if she had stressed how modest it was.

Changing our eating habits is easier said than done, of course. People need a nudge. If weight gain were instant, that might be enough. But it is not. Some other signal is required and price is the most effective. If people do not feel it on their waistlines, they will do in their pockets.

That is what has fuelled debate about a sugar tax. In 2013, Mexico introduced a sugar tax of one peso per litre of fizzy drink. In the first three months of 2014 there was a 10 per cent fall in consumption of sugary drinks. In 2011, Hungary imposed a tax on products containing high amounts of salt or sugar. The average price of the products rose 27 per cent and within a year consumption had fallen by up to 15 per cent.

Imposing a sugar tax would, however, be controversial and difficult (as argued in The Independent yesterday). Moreover, no tax could reasonably be imposed at the punitive levels predicted for the rise in chocolate prices – up by 100 per cent in the next five years, driven by the market alone.

If this price rise comes to pass it might help deliver what years of health initiatives have failed to do. A chocolate bar less a day could keep obesity at bay.