My son is a poor appetite, sleep is not practical, in the middle always wake up, how to do?

How old is kid. The appetite parameters and sleep habits of kids vary with age and stage of growth. The rapid growth rate of the first yr slows to 1/3 as fast by 2, picking up again by puberty. Appetite reflects growth rate & state of health. Sleep habits follow a variety of influences, mostly anxiety-separation issues in toddlers. Clearly stating a kids age/stage will permit for focused answers.
I've tried to. Understand your question but I can't. Will you please rephrase your question?