Explanation

Prolonged starvation causes marasmus due to a generalized wasting of body because of both energy and protein deficiency. The body becomes lean and weak, eyes depressed and skin wrinkled. Kwashiorkor is a disease caused by continued deficiency of proteins in diet although energy intake may be adequate. Rickets (in children) occurs due to deficiency of vitamin-D. Pellagra occurs due to deficiency of nicotinamide (vitamin-$B_{3}$).