People who don't get enough food often experience hunger, and hunger can lead to malnutrition over the long term. But someone can become malnourished for reasons that have nothing to do with hunger. Even people who have plenty to eat may be malnourished if they don't eat food that provides the right nutrients, vitamins, and minerals.
Some diseases and conditions prevent people from digesting or absorbing their food properly. For example:
- Someone with celiac disease has intestinal problems that are triggered by a protein called gluten, which is found in wheat, rye, and barley.
- Kids with cystic fibrosis have trouble absorbing nutrients because the disease affects the pancreas, an organ that normally produces enzymes necessary for digestion.
- Kids who are lactose intolerant have difficulty digesting milk and other dairy products. By avoiding dairy products, they're at higher risk of malnutrition because milk and dairy products provide 75% of the calcium in America's food supply.
Someone who doesn't get enough of one specific nutrient has a nutritional deficiency, a form of malnutrition (although it doesn't necessarily mean the person will become seriously ill). The most common form of malnutrition in the world is iron deficiency, which can lead to anemia. The World Health Organization (WHO) estimates that as many 2 billion people worldwide don't have enough iron (which is found in foods like red meat, egg yolks, and fortified flour, bread, and cereals) in their diets
Credits to:
http://kidshealth.org/parent/growth/feeding/hunger.html
