The world’s poorest families are cutting back on food and sending children out to work to pay for food amid soaring prices, according to a survey by British charity group Save the Children.

If no concerted action is taken, half a billion children will grow up physically and mentally stunted

In countries which are home to half the world’s malnourished children, a third of parents surveyed revealed that their children complained they did not have enough to eat. One in six said their children were skipping school to work for food.

The children’s charity is calling on the UK government to help lead a push to reduce hunger and protect children from food price spikes.

It is urging Prime Minister David Cameron to kickstart this with a “world hunger summit” at the Olympics – a time when world leaders will be in London – to tackle malnutrition.

The survey, conducted by the charity in India, Nigeria, Pakistan, Peru and Bangladesh, provides a snapshot of the hardship that families are facing in countries already experiencing high rates of malnutrition.

In its new report, A Life Free from Hunger: Tackling Child Malnutrition, the charity says that rising food prices and lack of global investment in tackling malnutrition are putting progress on child mortality at risk.

It warns that if no concerted action is taken, half a billion children will grow up physically and mentally stunted over the next 15 years.

The chief executive of Save the Children, Justin Forsyth, said: “Every hour of every day, 300 children die because of malnutrition, often simply because they don’t have access to the basic, nutritious foods that we take for granted in rich countries.

“By acting on hunger and malnutrition, world leaders have the chance to change this for millions of children across the world.”