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. It is important to note that the BMI is a statistical estimate and some individuals classified as underweight may be perfectly healthy. In fact, caloric restriction may be a viable means of increasing the lifespan, and it can easily lead to a BMI of less than 18.5. 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, which can run as high as 50% in parts of sub-Saharan Africa and south Asia. The effects of primary malnutrition may be amplified by disease; even easily treatable diseases such as diarrhea may lead to death.
In the presence of adequate food resources, being underweight can sometimes be the result of mental or physical disease. There are hundreds of possible medical causes for excessive weight loss or a person being underweight. Some of the more prevalent include:
Poverty
Famine
Torture
Cancer or Cancer Treatment
Tuberculosis
Hyperthyroidism
Type 1 Diabetes
Anxiety and depressive disorders
Drug abuse
Inflammatory bowel disease
Malfunctioning digestive organs
Dental pain
Over-training (endurance sports)
HIV/AIDS
Genetics
Stimulant use
Naturally light weight.
Problems
The most immediate problem with 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, they can feel fit and may be brilliant for example in endurance sports. After the occurrence of first spontaneous fractures the damage is often already irreversible.
How to Gain Weight ?
If an individual is severely underweight to the point where problems with his or her health develop, it may be necessary for the person to make a concentrated effort to gain weight. The treatment for an underweight individual is to increase the food energy intake so that more food energy is consumed than is being used as work. It is usually suggested that weight training is also to be undertaken to increase muscle mass.
If weight loss results from a disease, resolving the illness and consuming adequate calories can bring many underweight individuals to a healthy body weight.
Showing posts with label Weight Loss. Show all posts
Showing posts with label Weight Loss. Show all posts
Saturday, October 25, 2008
DIETING AND ITS EFFECTS
Dieting is the practice of ingesting food in a regulated fashion to achieve or maintain a controlled weight. In most cases the goal is weight loss in those who are overweight or obese, but some athletes aspire to gain weight (usually in the form of muscle) and diets can also be used to maintain a stable body weight.
Types of dieting
There are several kinds of diets:
Weight-loss diets restricts the intake of specific foods, or food in general, to reduce body weight. What works to reduce body weight for one person will not necessarily work for another, due to metabolic differences and lifestyle factors. Also, for a variety of reasons, most people find it difficult to maintain significant weight loss over time — among individuals that have lost 10% or more of body weight, only 20% are able to maintain that weight loss for a full year.
Many professional athletes impose weight-gain diets on themselves. American football players may try to "bulk up" through weight-gain diets in order to gain an advantage on the field with a higher mass.
Individuals who are underweight, such as those recovering from anorexia nervosa or starvation, may adopt weight-gain diets which, unlike those of athletes, have the goal of restoring normal levels of body fat, muscle, and stores of essential nutrients.
Many people in the acting industry may choose to lose or gain weight depending on the role they are given.
As more cultures scrutinize their diets, many parents consider putting their children on restricted diets that actually do more harm than good. This is extremely harmful to a young child's health because a full and balanced diet (fats, carbohydrates, protein, vitamins, minerals, fiber, etc.) is needed for growth. A doctor should be consulted before putting any child on a specialized diet.
Research also shows that putting children on diet foods can be harmful. The brain is unable to learn how to correlate taste with nutritional value, which is why such children may consistently overeat later in life despite adequate nutritional intake.
Fat loss versus muscle loss
Weight loss typically involves the loss of fat, water and muscle. A dieter can lose weight without losing much fat. Ideally, overweight people should seek to lose fat and preserve muscle, since muscle burns more calories than fat. Generally, the more muscle mass one has, the higher one's metabolism is, resulting in more calories being burned. Approximately 14 kilocalories are burned per pound of muscle at rest. Since muscles are more dense than fat, muscle loss results in little loss of physical bulk compared with fat loss. To determine whether weight loss is due to fat, various methods of measuring body fat percentage have been developed.
Muscle loss during weight loss can be restricted by regularly lifting weights (or doing push-ups and other strength-oriented calisthenics) and by maintaining sufficient protein intake. According to the National Academy of Sciences, the Dietary Reference Intake for protein is "0.8 grams per kilogram of body weight for adults."
Those on low-carbohydrate diets, and those doing particularly strenuous exercise, may wish to increase their protein intake which is necessary. However, there may be risks involved. According to the American Heart Association, excessive protein intake may cause liver and kidney problems and may be a risk factor for heart disease.There is no conclusive evidence that moderately high protein diets in healthy individuals are dangerous, however; it has only been shown that these diets are dangerous in individuals who already have kidney and liver problems.
How the body gets rid of fat
All body processes require energy to run properly. When the body is expending more energy than it is taking in (e.g. when exercising), the body's cells rely on internally stored energy sources, like complex carbohydrates and fats, for energy. The first source the body turns to is glycogen (by glycogenolysis). Glycogen is a complex carbohydrate (in total about 2000 kcal). 65% is stored in skeletal muscles and the rest in the liver. It is created from the excess of ingested macronutrients, mainly carbohydrates. When those sources are nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. In this process, fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to make energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.
Fats are also secreted by the sebaceous glands (in the skin).
Types of dieting
There are several kinds of diets:
Weight-loss diets restricts the intake of specific foods, or food in general, to reduce body weight. What works to reduce body weight for one person will not necessarily work for another, due to metabolic differences and lifestyle factors. Also, for a variety of reasons, most people find it difficult to maintain significant weight loss over time — among individuals that have lost 10% or more of body weight, only 20% are able to maintain that weight loss for a full year.
Many professional athletes impose weight-gain diets on themselves. American football players may try to "bulk up" through weight-gain diets in order to gain an advantage on the field with a higher mass.
Individuals who are underweight, such as those recovering from anorexia nervosa or starvation, may adopt weight-gain diets which, unlike those of athletes, have the goal of restoring normal levels of body fat, muscle, and stores of essential nutrients.
Many people in the acting industry may choose to lose or gain weight depending on the role they are given.
As more cultures scrutinize their diets, many parents consider putting their children on restricted diets that actually do more harm than good. This is extremely harmful to a young child's health because a full and balanced diet (fats, carbohydrates, protein, vitamins, minerals, fiber, etc.) is needed for growth. A doctor should be consulted before putting any child on a specialized diet.
Research also shows that putting children on diet foods can be harmful. The brain is unable to learn how to correlate taste with nutritional value, which is why such children may consistently overeat later in life despite adequate nutritional intake.
Fat loss versus muscle loss
Weight loss typically involves the loss of fat, water and muscle. A dieter can lose weight without losing much fat. Ideally, overweight people should seek to lose fat and preserve muscle, since muscle burns more calories than fat. Generally, the more muscle mass one has, the higher one's metabolism is, resulting in more calories being burned. Approximately 14 kilocalories are burned per pound of muscle at rest. Since muscles are more dense than fat, muscle loss results in little loss of physical bulk compared with fat loss. To determine whether weight loss is due to fat, various methods of measuring body fat percentage have been developed.
Muscle loss during weight loss can be restricted by regularly lifting weights (or doing push-ups and other strength-oriented calisthenics) and by maintaining sufficient protein intake. According to the National Academy of Sciences, the Dietary Reference Intake for protein is "0.8 grams per kilogram of body weight for adults."
Those on low-carbohydrate diets, and those doing particularly strenuous exercise, may wish to increase their protein intake which is necessary. However, there may be risks involved. According to the American Heart Association, excessive protein intake may cause liver and kidney problems and may be a risk factor for heart disease.There is no conclusive evidence that moderately high protein diets in healthy individuals are dangerous, however; it has only been shown that these diets are dangerous in individuals who already have kidney and liver problems.
How the body gets rid of fat
All body processes require energy to run properly. When the body is expending more energy than it is taking in (e.g. when exercising), the body's cells rely on internally stored energy sources, like complex carbohydrates and fats, for energy. The first source the body turns to is glycogen (by glycogenolysis). Glycogen is a complex carbohydrate (in total about 2000 kcal). 65% is stored in skeletal muscles and the rest in the liver. It is created from the excess of ingested macronutrients, mainly carbohydrates. When those sources are nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. In this process, fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to make energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.
Fats are also secreted by the sebaceous glands (in the skin).
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