The WHO said it was working with the UN's World Food Programme (WFP) to ensure food was delivered to one million people living in Ebola quarantine zones in Guinea, Liberia and Sierra Leone.
"Food has been delivered to hospitalised patients and people under quarantine who are not able to leave their homes to purchase food. Providing regular food supplies is a potent means of limiting unnecessary movement," the WHO said.
The WFP is stepping up emergency food deliveries to the quarantined areas, which include severely affected cities such as Gueckedou in Guinea, Kenema and Kailahun in Sierra Leone and Foya in Liberia.
While Nigeria appears to be containing its smaller outbreak, Liberia and Sierra Leone are struggling to halt the spread of the deadly virus.
Liberia has, however, found all 17 suspected Ebola patients who fled a quarantine centre in Monrovia at the weekend and transferred them to another clinic.
Information minister Lewis Brown also said three infected African doctors who had received the experimental Ebola drug Zmapp were showing "remarkable signs of improvement".