GH1 and nutritional deficiency disease: During the period of free food supply, immediately after malnutrition, catch-up growth results from two apparently conflicting actions associated with the action of GH and ghrelin [22], since in this period, hepatic resistance to GH ends, and the elevated GH levels result in elevated IGF-1 levels that act on target tissues to promote higher than normal protein synthesis and cell division, leading to catch-up growth.