In the global，a lot of people have problems in health, the obesity is on behalf of these problems. “Particularly affected are the USA, where 35.5% of men and 35.8% of women were classified as obese in 2010” (Lehnert et al, 2013, p. ?). In order to solve this problem, scientist try to learn more about the obesity, and they find one reason that causes obesity is the environment. People are struggle in the busy work and they need more nutrition. What’s more? In the modern life we have a large number of technologies to make it possible. That means people can easily get more nutrition and have problems in obesity. And another reason is the people have less sleep, because of the stress of work and study. Other reasons like less sports, genetic disease of obesity, the hormone and the mental factor also make up the most factor of obesity.
At first, the environment which causes the obesity include two parts, one of them is social environment and the other is economic environment. “The current social environment in the United States encourages consumption of energy and discourages expenditure of energy (10, 11). Possible factors in the environment that promote overconsumption of energy include the easy availability of a wide variety of good-tasting, inexpensive, energy-dense foods and the serving of these foods in large portions”. (Hill et al, 2013) In this situation, people rise the risk of have problem in obesity. Another social environment is people in busy work easier to have obesity, “Time pressure is emerging as a modern malaise, People need time to keep healthy, to exercise and to maintain strong social and family bonds. If urban designs or environmental solutions can reduce time demands they may directly improve health and social outcomes. However, where they increase time demands they may have unanticipated health costs” (Lyndall,2007) Now people don’t have enough time to do sports and they are struggle in so much stress, which made them need more food to provide the energy. It has been a die circulation, where people are busy for working, then they eat a lot of food without controlling, then they continue to work without do any sports to digest them, the action comes back in cycle.in this case, people get more nutrition and fat, so that they drop in obesity.
The other reason is economic environment, “Economists’ first law of demand implies that a decrease in the price of food will cause consumption to increase (43). Moreover, if the price of calorie-dense, prepackaged, and/or prepared foods (e.g., fast food) falls faster than for less calorie-dense foods (e.g., vegetables), then individuals will shift their consumption toward these cheaper alternatives. Between 1985 and 2000, the price of fresh fruits and vegetables, fish, and dairy products increased by 118%, 77%, and 56%, respectively, whereas sugar and sweets, fats and oils, and carbonated beverages (54) increased at lower rates—46%, 35%, and 20%”.（ Finkelstein，2005） So people more like to choose the food with higher caloric which seems like cheaper than the healthy food. Therefore, people are struggle in obesity.
The second thing that cause the obesity is genetic disease of obesity. General parents obese or their family has a history of obesity. their children have the high risk to be obese. “Empirical methods to test this hypothesis have not thus far adequately controlled for the endogeneity of obesity. We use variation in genotype to predict variation in phenotype (obesity). Genetic information from specific genes linked to obesity in the biomedical literature provides strong exogenous variation in the body mass index and thus can be used as instrumental variables. These genes predict swings in weight of between 5 and 20 pounds for persons between five and six feet tall.”(Norton et al, 2008)and British scientists have discovered a gene variant that regulates the amount of fat in the body. People with the gene variant weighed an average of 1.2 kilograms more than people without it. That shows why the gene cause the obesity.
The last thing that cause the obesity is the hormone. Scientist says that a key hormone in inducing hunger, leptin also known as the anti-obesity factor, controls our appetite for food. people who lack leptin love all of the food and eat so much. And in the end, they become the obese. “Growth hormone (GH) secretion, either spontaneous or evoked by provocative stimuli, is markedly blunted in obesity. In fact obese patients display, compared to normal weight subjects, a reduced half-life, frequency of secretory episodes and daily production rate of the hormone. Recent evidence suggests that leptin, the product of adipocyte specific ob gene, exerts a stimulating effect on GH release in rodents; should the same hold true in man, the coexistence of high leptin and low GH serum levels in human obesity would fit in well with the concept of a leptin resistance in this condition. Concerning the influence of metabolic and nutritional factors, an impaired somatotropin response to hypoglycaemia and a failure of glucose load to inhibit spontaneous and stimulated GH release are well documented in obese patients” (Pincelli,1999) the study really shows that the hormone causes the obesity.
In conclusion, obesity is generally divided into two categorise. One is obesity caused by diseases, which is caused by endocrine disorder caused by diseases (encephalitis, brain tumor, or chronic diseases requiring hormones or taking hormones due to illness), another reason is the gene people get from their parents or the gene has been changed by some factors, that makes people can’t control themselves to eat, the they have trouble in obesity. the last reason I want to show is the environment where we live in. we can easier get the food we like and we consumed too much calories in our daily life, which greatly exceeds the calories we need. Then the fat and nutrition are store by our body. We become obese in this way.
References
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- Norton, E. C., & Han, E. (2008). Genetic information, obesity, and labor market outcomes. Health Economics, 17(9), 1089-1104.
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