It has been a week since Alister was locked up in a cage. During that time, he had practiced his mind control superpower to pass the time.
Perhaps out of kindness, Alister had prevented the death of the abducted children who were about to die of starvation. He used his viral energy to convert it into energy and nutrients and passed it to the children who were about to die.
It wasn't that their kidnappers didn't give them food. However, the kidnappers seemed to have preferential treatment for some of the abducted children. Those children that they determined to be of high quality and could fetch for a good price were given full nutritious meals compared to those who weren't.
Alister was included in that but the lower-quality children could barely have a full meal so they were malnourished and were about to die from starvation.
