Obesity
9th and 10th Grade Informational Reading Texts
Obesity is a disease in which excess body fat has accumulated to the extent that it is likely to have negative effects on health. Obesity is commonly diagnosed on the basis of the body mass index (BMI). BMI is an estimate of body fatness based on a person's weight relative to his or her height. BMI is calculated by dividing a person's weight (in kilograms) by the square of the person's height (in meters). A BMI value of 18.5 to 25 kg/m2 is considered normal. A BMI greater than 30 kg/m2 classifies a person as obese.
Obesity is diagnosed when a child has a BMI that is greater than the 95th percentile of the reference values for children of the same age. This means that the child's BMI is higher than that of 95 percent of same-aged children in the reference sample. The reference values are based on large samples of children from the mid-to-late 20th century, before the recent rise in childhood obesity.
The medical profession breaks down obesity into additional categories, although the exact delineation of the categories is not agreed upon universally. Commonly accepted categories include; severe obesity, morbid obesity and super obesity. Fat Distribution in Obesity:
Obesity can also be categorized in terms of fat distribution, as measured by waist-to-hip ratio waist circumference divided by hip circumference.
In 1997, the World Health Organization formally recognized obesity as a global epidemic. Given its high prevalence, costs, and adverse health impacts, obesity is now considered one of the most serious public health problems of the 21st century. If rates of obesity keep increasing, obesity may soon surpass more traditional public health concerns, such as under nutrition and infectious diseases.
In 2014, about 600 million adults, (13%) worldwide were classified as obese, but in developed countries, obesity was much more prevalent. In the United States, for example, almost 37% of adults were classified as obese in 2014. Rates of obesity have risen dramatically over the past several decades. Obesity rates are also rising in the developing world, especially in urban settings. The only remaining region of the world where obesity is not common is sub-Saharan Africa.
Within populations, rates of obesity tend to be higher among women than men.
Rates of obesity also tend to increase with age, at least up to the ages of 50 or 60 years old. Obesity is less prevalent in children, but childhood obesity rates are rising in many regions of the world. In 2014, an estimated 42 million children below the age of five were obese. The earlier in life a child becomes obese, the more likely it is that the child will remain obese and become an obese adult.
Like many other diseases, most cases of obesity are the result of interplay between genetic and environmental factors. Obesity is most commonly caused by a combination of excessive food intake, inadequate physical activity, and genetic susceptibility.
A recently proposed physiological mechanism for the development of obesity is leptin resistance. Leptin is called the satiety hormone. It is secreted by fat cells and helps regulate appetite based on the body's fat reserves. When fat reserves are high, more leptin is secreted and appetite is inhibited, so you eat less. The opposite occurs when fat reserves are low. In obesity, decreased sensitivity to leptin occurs, resulting in an inability to detect satiety, despite high fat reserves. As a consequence, people with leptin resistance never feel satiated and are likely to overeat and gain more weight.
Obesity increases the risk of many other health problems and diseases, including cardiovascular disease, type 2 diabetes, fatty liver, certain types of cancer, pancreatitis, osteoarthritis, obstructive sleep apnea, and asthma. The health consequences of obesity are mainly due to the effects of either increased fat mass or increased numbers of fat cells. Extra weight from excess body fat places a lot of stress on the body and its organ systems, causing diseases such as osteoarthritis and obstructive sleep apnea. An increased number of fat cells increases inflammation and the risk of blood clots. It also changes the body's metabolism, altering the body's response to insulin and potentially leading to insulin resistance and type 2 diabetes. This explains why the link between obesity and type 2 diabetes is so strong. Not surprisingly, obesity has been found to reduce life expectancy. On average, obesity reduces life expectancy by six or seven years. super obesity reduces life expectancy by as much as ten years.
Most cases of obesity are treatable or preventable through changes in diet and physical activity that restore energy balance to the body. In fact, obesity is one of the leading preventable causes of disease and death worldwide.
Obesity is diagnosed when a child has a BMI that is greater than the 95th percentile of the reference values for children of the same age. This means that the child's BMI is higher than that of 95 percent of same-aged children in the reference sample. The reference values are based on large samples of children from the mid-to-late 20th century, before the recent rise in childhood obesity.
The medical profession breaks down obesity into additional categories, although the exact delineation of the categories is not agreed upon universally. Commonly accepted categories include; severe obesity, morbid obesity and super obesity. Fat Distribution in Obesity:
Obesity can also be categorized in terms of fat distribution, as measured by waist-to-hip ratio waist circumference divided by hip circumference.
In 1997, the World Health Organization formally recognized obesity as a global epidemic. Given its high prevalence, costs, and adverse health impacts, obesity is now considered one of the most serious public health problems of the 21st century. If rates of obesity keep increasing, obesity may soon surpass more traditional public health concerns, such as under nutrition and infectious diseases.
In 2014, about 600 million adults, (13%) worldwide were classified as obese, but in developed countries, obesity was much more prevalent. In the United States, for example, almost 37% of adults were classified as obese in 2014. Rates of obesity have risen dramatically over the past several decades. Obesity rates are also rising in the developing world, especially in urban settings. The only remaining region of the world where obesity is not common is sub-Saharan Africa.
Within populations, rates of obesity tend to be higher among women than men.
Rates of obesity also tend to increase with age, at least up to the ages of 50 or 60 years old. Obesity is less prevalent in children, but childhood obesity rates are rising in many regions of the world. In 2014, an estimated 42 million children below the age of five were obese. The earlier in life a child becomes obese, the more likely it is that the child will remain obese and become an obese adult.
Like many other diseases, most cases of obesity are the result of interplay between genetic and environmental factors. Obesity is most commonly caused by a combination of excessive food intake, inadequate physical activity, and genetic susceptibility.
A recently proposed physiological mechanism for the development of obesity is leptin resistance. Leptin is called the satiety hormone. It is secreted by fat cells and helps regulate appetite based on the body's fat reserves. When fat reserves are high, more leptin is secreted and appetite is inhibited, so you eat less. The opposite occurs when fat reserves are low. In obesity, decreased sensitivity to leptin occurs, resulting in an inability to detect satiety, despite high fat reserves. As a consequence, people with leptin resistance never feel satiated and are likely to overeat and gain more weight.
Obesity increases the risk of many other health problems and diseases, including cardiovascular disease, type 2 diabetes, fatty liver, certain types of cancer, pancreatitis, osteoarthritis, obstructive sleep apnea, and asthma. The health consequences of obesity are mainly due to the effects of either increased fat mass or increased numbers of fat cells. Extra weight from excess body fat places a lot of stress on the body and its organ systems, causing diseases such as osteoarthritis and obstructive sleep apnea. An increased number of fat cells increases inflammation and the risk of blood clots. It also changes the body's metabolism, altering the body's response to insulin and potentially leading to insulin resistance and type 2 diabetes. This explains why the link between obesity and type 2 diabetes is so strong. Not surprisingly, obesity has been found to reduce life expectancy. On average, obesity reduces life expectancy by six or seven years. super obesity reduces life expectancy by as much as ten years.
Most cases of obesity are treatable or preventable through changes in diet and physical activity that restore energy balance to the body. In fact, obesity is one of the leading preventable causes of disease and death worldwide.