Hunger and Malnutrition

We've all seen news reports about people who are starving in countries plagued by war or drought. Unfortunately, many people in the world go hungry because they can't get enough to eat most of the time.

According to the UN World Food Programme, over 1 billion people in the world don't have enough to eat. That's more than the entire population of the United States, Canada, and the European Union. Every 6 seconds a child dies from malnutrition and related causes.

What Are Hunger and Malnutrition?

We all feel hungry at times. Hunger is the way the body signals that it needs to eat. Once we're able to eat enough food to satisfy our body's needs, we stop being hungry. Teens can feel hungry a lot because their rapidly growing and developing bodies demand extra food.

People with malnutrition lack the nutrients necessary for their bodies to grow and stay healthy. Someone can be malnourished for a long or short period of time, and the condition may be mild or severe. Malnutrition can affect someone's physical and mental health. People who are suffering from malnutrition are more likely to get sick; in very severe cases, they may even die from its effects.

Kids who are chronically malnourished don't grow as tall as they should (a condition referred to as stunted growth) and are underweight as well. (People also can become underweight because they have an illness, and some are underweight because of their genes.)

What Causes Hunger and Malnutrition?

People suffer from hunger because they don't get enough food, and not getting enough food over the long term can lead to malnutrition. But someone can become malnourished for reasons that have nothing to do with hunger.

People who have plenty to eat may still be malnourished if they don't eat food that provides the right nutrients, vitamins, and minerals.

Some people become malnourished because they have a disease or condition that prevents them 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. Celiac disease can interfere with the intestine's ability to absorb nutrients, which may result in nutritional deficiencies.

People with cystic fibrosis have trouble absorbing nutrients because the disease affects the pancreas, an organ that normally produces chemical substances called enzymes that are necessary for digesting food.

If you don't get enough of one specific nutrient, that's a nutritional deficiency, a form of malnutrition (although it doesn't mean you will necessarily 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 as 2 billion people worldwide don't have enough iron in their diets. Iron comes from foods like red meat, egg yolks, and fortified flour, bread, and cereals.

Who Is at Risk for Hunger and Malnutrition?

No matter what country they live in, poor people are most likely to suffer from hunger and malnutrition. In poor countries, natural disasters — such as the severe droughts that African countries often experience — can contribute to malnutrition because they make it hard for people to get the food that they need.

In the United States, food manufacturers fortify some common foods with vitamins and minerals to prevent certain nutritional deficiencies. For example, the addition of iodine to salt helps prevent some thyroid gland problems; the folic acid that's added to foods can help prevent certain birth defects; and added iron can help prevent iron-deficiency anemia.

Malnutrition affects people of every age, although infants, children, and adolescents may suffer the most because many nutrients are critical for normal growth and development. Older people may develop malnutrition because aging, illness, and other factors can sometimes lead to a poor appetite, so they may not eat enough.

Alcohol can interfere with nutrient absorption, so alcoholics may not benefit from the vitamins and minerals they consume. People who abuse drugs or alcohol might be malnourished or underweight because they don't eat properly. People with anorexia, bulimia, or another eating disorder are also not eating properly and are at risk of malnutrition.

If you're on a special diet, you need to be careful about eating balanced meals and a variety of foods to get the right nutrients. Vegetarians and vegans, for example, need to make sure they get enough protein and vitamins like B12.

What Happens to Someone Who Is Malnourished?

Malnutrition harms people both physically and mentally. The more malnourished someone is — in other words, the more nutrients they're missing — the more likely it is that person will have problems.

The signs and symptoms of malnutrition depend on which nutritional deficiencies a person has, although they can include:

  • fatigue and low energy
  • dizziness
  • poor immune function (which can cause the body to have trouble fighting off infections)
  • dry, scaly skin
  • swollen and bleeding gums
  • decaying teeth
  • slowed reaction times and trouble paying attention
  • underweight
  • poor growth
  • muscle weakness
  • bloated stomach
  • bones that break easily
  • problems with organ function
  • problems learning

When a pregnant woman is malnourished, her child may weigh less at birth and have a smaller chance of survival.

Vitamin A deficiency is the biggest cause of preventable blindness in the developing world. Children in developing countries who have a severe vitamin A deficiency as a result of malnutrition have a greater chance of getting sick or of dying from infections such as diarrhea and measles.

Iodine deficiency, another form of malnutrition, can cause mental retardation, delayed development, and even blindness in severe cases. Iron deficiency can cause a person to be less active and less able to concentrate. Students who are malnourished often have trouble keeping up in school.

What Can Doctors Do?

Fortunately, many of the harmful effects of malnutrition can be reversed, especially if a person is only mildly or briefly malnourished. If you or your parents think you aren't getting enough of the right nutrients, you can seek advice from your doctor, who may look for signs of malnutrition in several ways. He or she will ask about how you are feeling, do a physical exam, and probably ask about the types and amounts of food in your diet.

When checking for malnutrition, a doctor may do one of several things:

  • look at a person's height and weight or body mass index (BMI) to get an idea of whether their weight is in the healthy range for their height and age
  • use blood tests to check for abnormalities
  • take X-rays or other types of images to look for signs of malnutrition in organs and bones
  • check for diseases or conditions that might be the underlying cause of malnutrition

To correct problems related to malnutrition, a doctor or dietitian will recommend specific changes in the types and quantities of foods that a person eats. Sometimes he or she will prescribe dietary supplements, such as vitamins and minerals. Other treatment may be necessary for people who are found to have a specific disease or condition causing their malnutrition.

Few teens in the United States and other developed nations suffer from serious malnutrition like that seen in Third World countries. Over time, even people who are very finicky eaters usually will get enough calories and nutrients to develop a healthy body. But if you're worried that you're not eating right or you're not feeling as well as you should, talk about your concerns with your parents, your doctor, or another trusted adult.

Reviewed by: Mary L. Gavin, MD
Date reviewed: November 2009

Kids Health

Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

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