The Royal Society of Public Health (RSPH) has called for a ban on takeaway deliveries to schools, after is research found one in four children had taken advantage of the service.

The RSPH research found that almost half of children though fast food takeaways were the companies most at fault for childhood obesity.

The survey of 500 children and young people aged between 13 and 18 found 25% had ordered a takeaway to be delivered to their school – in most cases ordering it via smartphone.

Suggestions from young people on how to tackle the problem included loyalty cards giving shoppers points for making healthy food choices, and encouraging supermarkets to give away fruit and vegetables that was too “wonky” to sell.

Other ideas include “film-style classifications” such as PG, 12 and 15 on foods that are high in fat, salt or sugar.

Children also said free wi-fi should be offered in healthy environments like parks, to discourage people from going to fast food restaurants or coffee shops in search of free Wi-Fi.

Shirley Cramer, chief executive, RSPH, said: “Our childhood obesity rates are disappointing, and tackling this must be a priority for government – there can be no excuses for fudging action on what is our number one public health challenge.”

”’There can be no excuses for fudging action on what is our number one public health challenge.

“While we welcome the Government’s introduction of a sugar levy on soft drinks, it is absolutely critical that the forthcoming childhood obesity strategy builds on this positive step with a basket of hard-hitting measures, from greater controls on advertising and marketing of junk food to food reformulation.”