Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health, leading to reduced life expectancy and/or increased health problems. Obesity increases the likelihood of various diseases, particularly heart disease, type two diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Obesity is most commonly caused by a combination of excessive food energy intake, lack of physical activity, and genetic susceptibility, although a few cases are caused primarily by genes, endocrine disorders, medications, or psychiatric illness. Evidence to support the view that some obese people eat little yet gain weight due to a slow metabolism is limited. On average, obese people have a greater energy expenditure than their thin counterparts due to the energy required to maintain an increased body mass. Obesity is a leading preventable cause of death worldwide, with increasing rates in adults and children. Authorities view it as one of the most serious public health problems of the 21st century. Obesity is stigmatized in much of the modern world (particularly in the Western world), though it was widely seen as a symbol of wealth and fertility at other times in history and still is in some parts of the world. In 2013, the American Medical Association classified obesity as a disease. According to the National Health and Nutrition Examination Surveys, approximately 69% of adults are overweight or obese, with more than 78 million adult Americans considered obese. Children have become heavier as well. In the past 30 years, the prevalence of childhood obesity has more than doubled among children ages 2 to 5, has nearly tripled among youth ages 6 to 11, and has more than tripled among ages 12 to 19. However, recent data suggest that the rate of overweight in children did not increase significantly between 1999 and 2008, except in the heaviest boys. This rate, though, remains alarmingly high. About 17% of American children ages 2 to 19, or 1 in 6, are obese. Further, the latest data continue to suggest that overweight and obesity are having a greater effect on minorities, including blacks and Hispanics. Obesity in childhood can add up to health problems—often for life. In adults, overweight and obesity are linked to increased risk of heart disease, type 2 diabetes (high blood sugar), high blood pressure, certain cancers, and other chronic conditions. Research has shown that obese children are more likely to be overweight or obese as adults.
Data from the 2005-2006 NHANES survey show that in the United States, nearly 13% of adults age 20 and older have diabetes, but 40% of them have not been diagnosed. Type 2 diabetes (formerly called adult-onset diabetes) accounts for up to 95 percent of all diabetes cases and almost all cases of undiagnosed diabetes. Pre-diabetes, which causes no symptoms, greatly raises the risk of a heart attack or stroke and of developing type 2 diabetes. Though rare in youth ages 12 to 19 years, type two diabetes is increasingly being seen in children and adolescents, particularly among minority communities. Moreover, the 2005-2006 NHANES data show that about 16% of these youth have pre-diabetes. In a recent national study, 58% of children diagnosed with type two diabetes were obese. And then how to reduce the obesity, the first step in preventing childhood obesity is for parents and