Despite what it may look like, starving children do not have bloated stomachs due to excess fat, like children who are overfed; rather, they have bloated stomachs due to a condition called protein calorie malnutrition, or PCM, which implies that the child is receiving enough calories, but not enough protein in those calories. A healthy body's blood vessels and organs secrete fluids, which are then flushed out by the lymphatic system. However, in a malnourished child who is suffering from PCM, the lymphatic system isn't effective enough to keep an appropriate amount of fluids flushed out, resulting in excess waste fluids being stored in the abdomen.
Protein calorie malnutrition is common in third-world countries where foods lacking most nutrients, like rice or maize, are abundant and the main daily food source, but other nutrient-rich foods, like fish, chicken or legumes, are scarce. The result is a diet high in nutrient- and protein-poor foods but sufficient in calorie count.
Protein calorie malnutrition can lead to two other diseases: marasmus and kwashiorkor. Marasmus is marked by severe weight loss, low body temperature, constipation and starvation diarrhea. Kwashiorkor is marked by edema in the hands and feet, a low capillary-filtration rate, hypoalbuminemia, or low concentrations of albumin in the blood, and dermatitis.