|MadSci Network: General Biology|
That is a very good question. The risks of being severely underweight are different from those associated with being severely overweight. People who are severely underweight are at risk for a variety of nutritional deficiency diseases and also often have impaired immune systems, making them much more susceptible to infections and their marginal deficiencies make healing more difficult. A classic example of severe underweight is people who have marasmus, or protein-energy malnutrition, brought about by lack of food. These individuals are at much higher risk of infection and an inability to recover from those infections. Severe overweight is associated with an increased risk of developing chronic diseases, such as heart disease. Severely overweight (also called morbid obesity)people may also have a variety of other problems, such as joint abnormalities (from the stress placed on their joints from the weight)and difficulty breathing lying down (from the weight placed on their lungs). Health risks of being slightly overweight or underweight are very individual. As long as there are no obvious clinical symptoms, there probably is not much difference from a health viewpoint.
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