Lidl has banned sweets and chocolate bars from the checkout at all 600 of its UK stores after surveying parents about the "pester power" of their children.

The discount supermarket said racks of sweets had been replaced with dried and fresh fruit, oatcakes and juices, following a trial of these healthier options at checkouts last year.

Lidl customer research showed that seven out of 10 customers would choose a sweet-free checkout over the traditional one laden with chocolate bars. In a survey for the supermarket, 68% of parents said they were pestered by their children for chocolate at the checkout, and 66% gave in some or all of the time.

One in six parents told the supermarket they spend £20-40 a month on supermarket snacks, while a similar number said they had used the offer of a "treat" as a reward for good behaviour during the shopping trip.

The supermarket claims it is the first UK supermarket to have removed sweets from all its checkouts. Although Tesco and Sainsbury's have removed sweets from counters at their larger outlets, they continue to be sold at the checkouts in convenience stores.

Ronny Gottschlich, managing director, Lidl UK, said: "We know how difficult it can be to say no to pester power, so by removing sweets and chocolates from our tills we can make it easier for parents to reward children in healthier ways."

The ban comes after a National Obesity Forum report showed that previous estimates that half the UK population will be obese by 2050 had understated the problem.

Katharine Jenner at Action on Sugar said campaigners were pleased with Lidl's decision. "It is an acknowledgement from the retailers that these products are not healthy," she said, but added: "It is one thing to put people off buying, it is another to make products healthier."