Child malnutrition is the biggest crisis that the flood-stricken areas of Pakistan face, warn UN aid agencies, although the general health situation is under control.
The UN Children's Fund (UNICEF) said over 10 million children had been affected by the flooding, including 2.8 million under five-year-olds.
"The emergency is far from over: large numbers of women and children have not been reached with the assistance they urgently need," said UNICEF spokeswoman Marixie Mercado.
"The risk of malnutrition looms large with the very young extremely vulnerable," she told journalists.
Mercado said the stuttering aid effort needed to be sustained and scaled up urgently to reach more children especially with food.
"If we do not, conditions for those affected will deteriorate. This could happen very rapidly and would result in a much worse condition than we have on our hands today," she said.
The World Food Programme said it had received about one sixth of the 600 million dollars (460 million euros) needed to ensure adequate supplies to avoid a deeper crisis.
"One of our biggest focuses right now is our concerns about nutrition for young children," said WFP spokeswoman Emilia Casella.
The UN's Office for the Coordination of Humanitarian Affairs repeated a call for donors to stump up more cash for the 2.01 billion dollar aid appeal, of which it has received less than one quarter, with shortages across the board in health, sanitation and shelter.
"We need more donors to respond to this in a big way and existing donors to dig deeper still," said Mercado.
About 5.6 million flood victims have been treated for diarrhoea, respiratory ailments, malaria and skin diseases, the World Health Organisation said.
Asked if the health situation was out of control following warnings of the threat of severe diarrhoeal diseases, WHO spokesman Paul Garwood said: "At the moment we're not seeing that that's the case."
Diarrhoea was about 30 percent up over the same season last year in Pakistan, he added, while cases of malaria and skin diseases were rising.
"All the conditions are there for a very worrying situation in terms of health but there has also been, as best as possible, a very robust response."