The spelling word that best completes the sentence is this: The children were suffering from starvation.
What is starvation?
Starvation is a severe deficiency in caloric energy intake, below the level needed to maintain an organism's life. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death.
Some of the symptoms of starvation are weight loss, fatigue, weakness, and muscle wasting. Supporting sustainable agriculture is a way to prevent starvation.