Underweight

For the financial securities rating, see Underweight (stock market).

Underweight

The term underweight refers to a human who is considered to be under a healthy weight. The definition is usually made with reference to the body mass index (BMI). A BMI of under 18.5 is usually referred to as underweight. This medical definition of underweight may differ from other uses of the term, such as those based on attractiveness.

Causes

The most common cause of a person being underweight is primarily malnutrition caused by the unavailability of adequate food. The effects of primary malnutrition may be amplified by disease; even easily treatable diseases such as diarrhea may lead to death.

Some people are skinny due to genetics, others due to poverty.

Being underweight can sometimes be the result of mental or physical disease, such as hyperthyroidism, cancer, or tuberculosis. People with gastrointestinal or liver problems may be unable to absorb nutrients adequately. People with eating disorders are likely to become underweight.

Problems

The immediate problem with being underweight is that it might be secondary to, and/or symptomatic of, an underlying disease. Unexplained weight loss requires professional medical diagnosis.

Underweight can also be a primary causative condition. Severely underweight individuals may have poor physical stamina and a weak immune system, leaving them open to infection. According to Robert E. Black of the Johns Hopkins School of Public Health, "Underweight status ... and micronutrient deficiencies also cause decreases in immune and non-immune host defenses, and should be classified as underlying causes of death if followed by infectious diseases that are the terminal associated causes." People who are malnutrative underweight raise special concerns, as not only gross caloric intake may be inadequate, but also intake and absorption of other vital nutrients, especially essential amino acids and micronutrients such as vitamins and minerals.

In women, being grossly underweight can result in amenorrhea (absence of menstruation) and possible complications during pregnancy. It can also cause anemia and hair loss.

Underweight is an established risk factor for osteoporosis, even for young people. This is a particular insidious consequence, because the affected persons do not notice the danger. After the occurrence of first spontaneous fractures the damage is often already irreversible.

Treatment

Diet

There are two ways to gain weight. There is an unhealthy way to gain weight and a healthy way to gain weight. The unhealthy route to gaining weight is consuming junk food and not getting adequate exercise. The healthy way to gain weight is by increasing calorie amounts of the food that you already eat. Placing high amounts of butter, cream or cheese sauces, peanut butter, olive oil, salad dressing, seeds, and nuts on foods help increase food calories. Eating calories dense foods can also be beneficial. Some examples of calorie dense foods are: dried fruits, cheese, raisins, and nuts. Drinking liquids with high calories can add up weight. Some examples of popular weight gain drinks are Ensure and Boost. Another examples are milk and fruit juice. Eating a healthy diet is also crucial in weight gain. Consuming starchy vegetables like potatoes and corn can also add weight gain. Eating protein, healthy fats, carbohydrates, vegetables, fruits are important for a weight gain diet. Nutritional supplements may be beneficial for people who aren't getting enough vitamins or minerals.

Exercise

Another way for underweight people to gain weight is by exercising to obtain muscle mass. Gaining muscle give you more body mass. Weight-lifting exercises help gain muscle.

See also

• Body image
• Stunted growth
• Malnutrition