Taxing chocolate and other sweet foods would be a more effective anti-obesity strategy than the new “sugar tax” on fizzy drinks, a new analysis suggests.

A major study by Oxford and Cambridge Universities and the London School of Hygiene and Tropical Medicine, predicts that adding 10 per cent to the price of confectionary, cakes and biscuits could lead to a 7 per cent drop in purchases.

The figures are similar to those for taxing sugar-sweetened drinks, where previous research suggests a 10 per cent price rise can reduce purchases by 6 per cent to 8 per cent.

However the latest study, published in BMJ Open, found that taxing sweet snacks could have an additional knock-on effect on the sale of other foods, leading to consumers cutting their buying of soft drinks, biscuits, cakes and savoury snacks as well.

Sweet snacks provide twice as much sugar in the diet as sugar-sweetened drinks, so the overall reduction on sugar intake would be greater than that observed with taxes on sugar-sweetened drinks alone, the report said.

The researchers found, for example, that increasing the price of chocolate snacks was estimated to result in a significant reduction in buying across most food categories, while a price increase on biscuits showed a potential reduction in the purchase of cakes (2.3 per cent) as well as chocolate and confectionery (1.7 per cent).