Psychological research on attempts to lose weight have led to the derivation of notions such as set-point theory, the externality hypothesis and the restrained eating hypothesis, each of which imply that not only are most of these attempts detrimental to ones health, but are also rather futile and may even result in the opposite of the desired effects occurring.
Obesity is most common amongst people living in Western society, with evidence suggesting that about 24% of men and 27% of women in the United States being regarded as thus (Williamson, 1995). It therefore comes as no surprise that an estimated 24% of men and 40% of women are dieting at any one time (Brownell & Rodin, 1994). However, even though it appears that we are aware of
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The dual-centres model of hunger (Valenstein, 1973; Winn, 1995), which proposed the idea that there were two specific centres in the brain, the lateral hypothalamus, and the ventromedial nucleus of the hypothalamus, of which decreased the experience of hunger (Anand & Brobeck, 1951) and increased the experience of hunger (Brobeck, Tepperman, & Long, 1943) respectively, was discredited with the discovery of the paraventricular nucleus of the hypothalamus. The paraventricular nucleus was found to stimulate eating after it had been injected with various neurotransmitters (Leibowitz, 1992). This new observation led to further studies, which have since focused more on neural circuits, for accumulating evidence suggests that the hypothalamus contains interacting systems, which regulate eating by monitoring many different physiological processes.
Glucose is a simple sugar that is an important source of energy (Weiten, 2001); the glucostatic theory proposes that hunger is regulated by the rise and fall of blood glucose levels (Mayer, 1955, 1968). Experiments in the manipulation of glucose levels found that a decrease in blood glucose increased hunger, and an increase in blood glucose levels decreased hunger. Mayer's theory also proposes that the fluctuation in blood glucose levels were monitored in the brain by glucostats, which are neurones that are sensitive to glucose in the surrounding fluid. The
Scientifically, it has been proven that one should not make long-term decisions while hungry. Students at the University of Gothenburg in Sweden studied whether or not it is smart to make a decision when you are ravenous. A hormone that is made in the gastrointestinal tract, called ghrelin enhanced this study. Ghrelin is released when your body is searching for food as energy. When you are no longer hungry, the manufacturing of ghrelin halts. Ghrelin is also associated with drug and alcohol intake. Tests were developed to demonstrate how this happens through living organisms, the researchers at the University of Gothenburg examined rats. Although rats are not humans, they can display human-like behaviors. When an extra amount of ghrelin was inserted into the rat, they went against their regular impulses. They would gain a
Obesity is an increasing issue in modern society. It has been deemed an ‘epidemic in the developed world’ and statistics (from Public Health England) show obesity in the United Kingdom has been on the rise for many years, with currently 61.9% of men and women being obese or overweight. In England alone, 1 in 4 adults (age 16 years or over) are currently obese – (25.6%) - placing more than half the adult population overweight or obese (HSE, 2014). This growing problem in developed countries is responsible for thousands of deaths each year due to a number of contributory factors.
Obesity is defined as a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduce life expectancy and/or increased health problems. “The problem of obesity is increasing in the United States. Understanding the impact of social inequalities on health has become a public health priority in the new millennium. Social, political, and economic factors now are acknowledged to be "fundamental" causes of disease that affect behavior, beliefs, and biology.” (Goodman, 2003) In the United States today, obesity has become an enormous problem. In the last 3 decades, the number of people overweight has increased dramatically. Obesity has not always been seen as a medical
In the United States today, obesity has become an enormous problem. In the last 3 decades, the number of people overweight has increased dramatically. A study done by the Centers of Disease Control showed that since 1980, one third of our adult population has become overweight. America is the richest but also the fattest nation in the world and our obese backsides are the butt of jokes in every other country (Klein 28). The 1980s were a time when Americans suddenly started going crazy over dieting, jumping onto the treadmills, and buying prepackaged non-fat foods. However, while all of that was going on, the number of obese Americans began to increase. According to a report in the Journal of the American Medical Association, 58 million
“Obesity is a disease that affects more than one-third of the U.S adult population (approximately 78.6 million Americans). The number of Americans with obesity had steadily increase since 1960, a trend that has slowed down in recent years but show no sign of reversing”.
68.8 percent of people in the United States and 30 percent of the entire global population are obese. “Obesity today is officially an epidemic; it is arguably the most pressing public health problem we face, costing the healthcare system an estimated $90 billion a year.” said Michael Pollan in “The Omnivore’s Dilemma: A Natural History of Four Meals.”
Summary: This article goes on to tell us what a problem obesity is becoming. It’s becoming such a problem that nowadays Overweight and obesity are the main risk factors for many non-communicable diseases like diabetes, cardiovascular diseases, musculoskeletal disorders, and some types of cancers. Statistics show, in both developed and developing countries, that the prevalence of overweight and obesity is growing. It used to be in just developed countries that obesity and overweight was a problem. But now, it’s a problem in both developed and developing
Obesity has become increasingly more prominent in American society. The Unites States has even been termed an overweight nation. Some twenty to thirty percent of American adults are now considered obese (Hwang 1999 and Hirsch et al 1997). With this in mind, Americans constantly look around themselves determining their weight status as well as that of those around them. While some Americans do fit the healthy category, others enter the underweight, overweight, and even obese categories, all of which can be unhealthy.
Obesity, defined as an excess of body fat, has become a serious public health concern in the United States (Morrill and Chinn 2004). Obesity rates in the United States have more than doubled since the 1960s, where one in eight men and women were estimated to be obese (Fryar et al. 2012). The prevalence of obesity has now jumped to more than one in three men and women in the United States (Ogden et al. 2014; Flegal et al. 2012). This rate has remained the same since 2003 and is seen for both men and women of all ages and in every racial or ethnic group (Ogden et al. 2013; Simon et al. , 2006).
Statistical information confirms: obesity and overweight have already turned into an issue of national concern. In 2002, “a National Survey conducted by American Sports Data revealed that 61% of adults in the U.S. felt that they were overweight, 19% admitting that they were ‘considerably’ overweight” (American Sports Data). The major causes of obesity, overweight, and similar nutritional problems included genetics, population trends, hurried lifestyles, high-carbohydrate diets, less demanding workplaces, smoking cessation, and social class aspects (American Sports Data). That hurried lifestyles and a less demanding workplace contribute in the development of obesity trends is clear. But even more importantly, because the number of those who are overweight or obese exceeds one half of the American population, the government must control our diets. The information about the costs of obesity and related diseases is even more compelling.
The presence of peripheral signals influences the hypothalamus through actions from afferent neurones and brainstem. The chemoreceptors also play important roles in controlling appetite. These receptors mediate vagal afferent and pass on the signal s to the nucleus of tractus solitaries (NTS) present in the brainstem. Gut hormones also work through this vagal pathway and brainstem (Schwartz et al, 2000). Hence, the orexigenic and anorexigenic neurons in the hypothalamus are mediated by neural and hormonal signals. These neurons will extend to various others in the extra-hypothalamic and intra-hypothalamic regions, such as the hypothalamic paraventricular nucleus (PVN), and lateral hypothalamus (LH) where some of the significant efferent pathways
Appetite is the desire to eat and the inner motivating force to pursuit, choose, and consume food [11]. Appetite is thought to be a complicated process which regulation involves the gastrointestinal tract, many hormones and the nervous system [12]. Nevertheless, satiation and satiety are involved in this complex process and both are associated with the inhibition of eating. Satiation is the feeling of satisfaction that makes an individual stop eating during a meal( intra-meal), while satiety is the feeling of fullness that carry on after eating, inhibiting further consumption of food till feeling of hunger appears again [11][13][14][15].
Ghrelin sends a message to the hypothalamus that monitors body functions. Once the hunger is appeased, there is a reduction in the production of ghrelin. Researchers believe that overwhelming elevations of ghrelin is the cause of overeating; however, researchers are unsure why the hormone increases. The body stores the nutrients in the stomach, and a nutrient reserve. Carlson (as cited in Novin, VanderWeele, and Rezek, 1973) explained that the hepatic portal vein in the liver transmits hunger signals to the brain when glucose is low. Unfortunately, the body uses up more energy than it takes in, which is the time the hunger cycle begins
In a normally functioning body, the intake of food triggers the
Obesity is classified as one of the extremely common and serious public health problems in the world. Overweight and obesity are the fifth leading global risks of mortality in the world (World Health Organization, 2009). Furthermore, they are one of the major factors of for a number of chronic diseases, such as cardiovascular diseases, heart disease, stroke, diabetes and cancer (World Health Organization, 2005). According to NHS UK, obesity is defined as a body mass index (BMI) of 30 or more for adults, and the UK 1990 growth reference curves are used to define obesity for Children (Cole TJ, Freeman JV, Preece MA, 1995). The growing challenge of obesity of Europe countries is remarkable among Asian countries .In 2008, 1.4 billion adults (35%) aged 20 and over were overweight and 500 million were obese (11%). More than 40 million children under the age of 5 were overweight or obese in 2012(World Health Organization, 2014). That is the global obesity situation. Furthermore, the obesity problem in the UK is not optimistic, the UK has the highest obesity rates among Europe countries, and this trend has strikingly increased over the recent years to the point where more than 20% of the population are now obese. (University of Birmingham, 2014) However, the obesity situation in Singapore is more worrisome. In 2010, 40% adults aged 18 to 69 were overweight and 10% were obese which is more than double the level seen in 1992. (Ministry of Health Singapore, 2010) This essay will