Save the Children has called for a summit on world hunger to be held in London during the Olympic Games, when many of the world's leaders will be in attendance.
Malnutrition could lead to physical and mental problems for up to 500 million children over the next 15 years, according to Save the Children.
The charity warns that much more needs to be done to tackle malnutrition in the world's poorest countries.
It said a survey carried out in India, Bangladesh, Pakistan, Nigeria and Peru showed that the latest increase in food prices had compounded the chronic problem of child malnutrition.
In its latest report, A Life Free from Hunger: Tackling Child Malnutrition, the charity said that rising food prices and lack of global investment in tackling malnutrition are putting progress on child mortality at risk.
Chief Executive Justin Forsyth has said that while progress has been made in reducing child deaths, down from 12 million to 7.6 million, this momentum will stall if malnutrition is not tackled.
The charity argues that while malnutrition is the underlying cause of a third of child deaths, it has not received the same high-profile campaigning and investment as other causes of child mortality, such as HIV/AIDS or malaria.