Understanding ObesityObesity is a medical condition in which excess body fat has accumul

Understanding Obesity

Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health. People are generally considered obese when their body mass index (BMI)，a measurement obtained by dividing a person' s weight by the square of the person' 8 height, is over 30 kg/n2, with the range 25-30kg/n2 defined as overweight. Some Asian countries use love values.

Causes

Obesity is most commonly caused by a combination of food intake, lack of physical activity, endocrine disorders, medications or mental illness. Evidence to support the view that obese people eat little yet gain weight due to a slow metabolism is not generally supported. On average, obese people have greater energy expenditure than their thin counterparts due to the energy required to maintain an increased body mass.

A 2006 review identified ten other possible contributors to the recent increase of obesity (1)insufficient sleep(2)endocrine disrupters(environmental pollutants that interfere with lipid metabolism), (3)decreased variability in surrounding temperature,(4)decreased rates of smoking, because smoking suppresses appetite, (5)increased use of medications that can cause weight gain(e.g., a typical antipsychotics), (6)proportional increases in ethic and age groups that tend to be heavier,(7)pregnancy at a later age(which may Cause susceptibility to obesity in children), (8)epigenetic risk factors passed on generationally, (9)natural selection for higher BMI, and(10)assortative mating leading to increased concentration of obesity risk factors (this would increase the number of obese people by increasing population variance in weight)

Effects on health

Excessive body weight is associated with various diseases, particularly cardiovascular diseases, diabetes mellitus Type 2, obstructive sleep apnea, certain types of cancer, osteoarthritis and asthma. As a result, obesity has been found to reduce life expectancy.

Obesity diminishes almost every aspect of health, from reproductive and respiratory function to memory and mood. Obesity increases the risk of several deadly diseases, including diabetes, heart disease and some cancers. It does this through a variety of pathways, some as straightforward as the mechanical stress of carrying extra pounds and some involving complex changes in-hormones and metabolism. Obesity decreases the quality and length of life and increased individual, national and global healthcare costs. The good news, though, is that weight loss can curtail some obesity-related risks. Losing as little as 5 to 10 percent of body weight offers meaningful health benefits to people who are obese even if they never achieve their "ideal" weight, and even if they only begin to lose weight later in life.

Prevention of obesity

Obesity is a leading preventable cause of death worldwide, with increasing rates in adults and children. In 2014, 600 million adults (13%) and 42 million children under the age of five were obese. Obesity is more common in women than men. 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 seen as a symbol of wealth and fertility at other times in history and still is in some part of the world. In 2013 the American Medical Association classified obesity as a disease.

Obesity is mostly preventable through a combination of social changes and personal choices. Changes to diet and exercising are the main treatments. Diet quality can be improved by reducing the consumption of energy-dense foods, such as those high in fat sugars. And by increasing the intake of dietary fiber. Medications may be taken, along with a suitable diet, to reduce appetite or decrease fat absorption. If diet, exercise and medication are not effective, a gastric balloon or surgery may be performed to reduce stomach volume or bowel length, leading to feeling full earlier or reduced ability to absorb nutrients from food

1、A person is usually considered obese when___.

A. his/her BMI reaches over 30kg/n2

B. his/her BMI ranges from 25-30kg/n2

C. he/she has accumulated excess body fat.

D. he/she eats too much.

2、What is the near-synonym to the word “susceptibility”(in the 1st sentence of the 2nd paragraph)？

A. Infection

B. Suspicion

C. Ailment

D. Tendency

3、What is true about obesity？

A. some people become obese easily because of genetic susceptibility

B. A slow metabolism explains why obese people eat little yet gain weight

C. Obese people need less energy required to maintain an increased body mass

D. Excessive food intake will definitely cause obesity

4、Potential reasons for the rise of weight gain include following except__.

A. side effects of some medications

B. endocrine dysfunction

C. inadequate sleep

D. excessive smoking

5、According to the passage, what is not the possible consequence of obesity.

A. Diabetes mellitus Type 1 and 2

B. Difficulty in breathing during sleep

C. Decreased life quality

D. Shorter life expectancy