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Revision notes 7.4 Section 7.4 Obesity Learning outcomes Discuss factors related to overeating and the development of obesity. Discuss prevention strategies and treatments for overeating and obesity. According to the World Health Organization (WHO), obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health and is a major preventable cause of death worldwide. Among adults, between 1976–80 and 1999–2002 the rate of obesity more than doubled, rising from 15 to 31%. The overall rates of obesity and being overweight in the USA were 47% in 1976–80 and 65% in 1999–2002. It has continued rising since then although some studies show the recent rise has not been statistically significant. According to Kessler (2010), three decades ago, fewer than 10% of Britons were obese; now it is 25%. It is projected that by 2050, obesity will be the norm in British society. To read more about this click here. In 1978, the typical teenage male in the USA drank about seven ounces of soft drinks daily. Today he drinks nearly three times that amount, deriving 9% of his daily caloric intake from soft drinks. Soft drinks and processed food contain large numbers of empty calories that have little nutritional benefit. Therefore, while many modern teens eat far more calories than their predecessors, they can be obese and have ailments associated with malnutrition such as calcium deficiency and an increased likelihood of bone fractures. Twenty years ago, US teenage males drank twice as much milk as soft drinks; now they drink twice as many soft drinks as milk. Only 13% of boys and 15% of girls consume the recommended amount of fruit. Only 29% of boys and 12% of girls consume the recommended amount of dairy foods. This suggests a lack of education as well as a lack of volition to eat healthily. © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com 1 The availability of fast food, processed food and a general lack of exercise have all contributed to this however, it should be noted: Not everyone is getting heavier and people are not forced to eat poor food and avoid exercise. Therefore, social scientists need to put forward theories as to why some people are becoming more obese whereas others are able to resist unhealthy temptations and remain healthy by eating good food and exercising regularly. The following factors should be discussed in the context of each other: No one perspective should be taken in isolation. Sociocultural factors There are a number of political, cultural and economic reasons for the explosion of obesity in the West. The sedentary lifestyle is a major cause. In the past, work usually meant physical toil, now work is usually mechanized or at least involves very little physical energy expenditure. The social learning theory assumes people learn behaviour via processes present in the environment or culture (e.g. modelling and conditioning) via reward and punishment. Wilkinson (2005) reported on a British study that analyzed 12 000 three-year-olds who were raised either by their grandparents or by their parents. The study suggests the risk for becoming overweight was 34% higher if grandparents cared for children full-time. It was further suggested that this was connected to grandparents using food as a reward for good behaviour as well as being less inclined to restrict children’s urges. Second-hand obesity is the notion that children learn to be obese. It is also an example of how the Bandurian concept of modelling can lead to a corrosive behaviour being passed onto a child (children learn lifelong habits while in the presence of their parents) at the same time that obesity is normalized. The increasing availability of unhealthy processed food and its use as a reward has meant obesity rates have soared. The fast food industry is an aggressive advertiser and targets children in particular by modelling product-consuming behaviour (e.g. celebrities endorsing the product) and providing positive associations with drinks and food. Ludwig et al. (2001) conducted an observational study at the Children’s Hospital in Boston on the relationship between soft drinks and obesity in children. The 19-month study involved 548 children whose average age was just under 12 years. It found that the chances of becoming obese increased significantly with each additional daily serving of sugar-sweetened drink (cited in Jacobson, 2005). In 2004, Coca-Cola and its subsidiaries spent $2.2 billion on promotions worldwide (Coca-Cola Company. Annual Report 2004.) Schlosser (2001) outlines how soft drink manufacturers deliberately target school children as they are still developing their taste preferences and habits. Establishing brand loyalty at a young age © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com 2 increases the chances of a child becoming a consumer of the product throughout their lifetime. Companies pay US school districts for exclusive marketing rights. For example, Coca-Cola has a 10-year exclusive contract with Colorado Springs that is worth between $8 million and $11 million (Kaufman, 1999). Again, this demonstrates deliberate targeting of children. McDonalds operates more playgrounds designed specifically to attract children and their parents to its restaurants than any other private entity in the USA. The playgrounds, and high sugar content of the products, provide positive associations with the industry and corporation (Schlosser, 2001). In 2010, a UK consumer advice group, Which? found 38% of 8–11-year-olds listed McDonalds as their favourite restaurant because of the toys and ‘happy meals’ the company marketed to them. Which? expressed concern over the use of the toys with fast food, arguing they contributed to pester-power (the habit of children nagging parents for a particular consumer product). Biological factors The medical establishment accept that only a small minority of obesity cases are caused by physiological abnormalities. Most cases of obesity are caused by poor diet (characterized by cheap, highly processed food), lack of exercise and lack of self-discipline. The following are examples of physiological abnormalities that can cause obesity. Hypothyroidism is sometimes associated with weight gain. However, patients with an underactive thyroid generally show only a moderate weight increase of 5–10 pounds. Very rare genetic disorders, including Froehlich’s syndrome in boys, Laurence–Moon–Biedl syndrome and Prader–Willi syndrome, cause obesity. Although most cases of obesity are caused by poor diet and a lack of exercise, this it does not mean that physiological factors have no part in shaping eating patterns. However, this can also be linked with secondhand obesity and learned lifestyles – healthy parents who eat healthily will pass that knowledge onto the child and vice versa. Obesity is being passed on via the cultural equivalent of the gene – the meme. Memes are ideas, symbols or behavioural practices transmitted from one mind to another through writing, speech, gestures, cultural or family rituals or other imitable phenomena. Memetic transmission of obesity is more likely than genetic transmission as the recent explosion in obese people points to an environmental change and a shift in how humans interact in their environment rather than an inherent genetic alteration. Clearly, body type is inherited, but lifestyle choices are the key. Children are not born with a predisposition to eat poor food and avoid exercise. There will always be biological variations in energy intake for individuals. Basal metabolic rate may well be under genetic influence (although definitive studies do not yet exist) and other bodily processes such as the rates of carbohydrate-to-fat oxidation, © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com 3 and the degree of insulin sensitivity, which are closely involved in energy balance and therefore body weight (Ravussin, 1993) may also play a part. But these processes alone cannot account for the rapid growth of obesity in society nor the obesity within individuals. There have always been different body styles in human history but never has the human body been so overweight on such a scale before. The evidence is weak for innate predetermined factors in individuals to explain the obesity epidemic, but that does not mean food cannot be designed to influence physiological mechanisms to make us eat more. Kessler (2010) argues: Higher sugar, fat and salt intake actually makes the individual want to eat more as they make the intake of food compelling for the brain. Neurons are stimulated and release dopamine, a chemical that has been linked with making people want to eat more. Food manufacturers understand this and deliberately engineer food to be ‘compelling.’ People reach a bliss point with food; it is here they get the greatest pleasure from sugar, fat or salt. He interviewed industry insiders who detailed how corporations deliberately design food to create a bliss point, making a product indulgent or high in hedonic value, maximizing the chances of the consumer eating more as well as receiving positive rewards for eating the product. Food itself has been deliberately changed in terms of its chemical composition: sugar, fat and salt are either loaded into a core ingredient (such as meat, vegetables, potato or bread), or layered on top of it, or both. Deep-fried tortilla chips are an example of loading – the fat is contained in the chip itself. When it is smothered in cheese, sour cream and sauce, it then becomes layered. Cognitive factors Eating healthily and exercising regularly takes self-discipline and motivation. Both are difficult to measure and to instil into others. Education is required to show people the effects of their lifestyle on their health. Cognitive dissonance is needed to change behaviour. Perception can be influenced by a number of factors. Fat-acceptance movements try to change opinions about how obesity should be seen – although they are rarely taken seriously by the mainstream medical establishment. Individuals with high self-acceptance (i.e. people who are happy with their lifestyle choices) and extreme weight are unlikely to enact change. Although gaining weight can be seen as a problem, losing weight and maintaining a healthy lifestyle is a bigger obstacle. According to the Malaysian Association for the Study of Obesity (MASO), poor problem-solving skills usually lead to negative coping mechanisms that may involve behaviour that promotes weight gain as well as behaviour that prohibits it being shed. © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com 4 Prevention strategies Clearly, the best way to deal with obesity is stop it developing in the first place. The following strategies are designed to remind people about maintaining a healthy lifestyle as well as to educate people about food. Education Many people remain ignorant about the food industry in terms of how food is produced and where it comes from. In 2002, the Royal Highland Education Trust (RHET) in Scotland interviewed 126 children aged 8 and 9. They found 30% did not know where eggs came from and over 50% thought oranges were grown in Scotland. Exercise and eating healthily are the best prevention but the Campaign to End Obesity in the USA states 52% of adults do not meet minimum physical activity recommendations while only 35.8% of high-school students are physically active for an hour or more every day. The campaign also notes that only 12% of adults and 2% of children eat a healthy diet consistent with federal nutrition recommendations. However, education only works if people want to lose weight. The absence of volition can be a major barrier to weight reduction and groups such as the fat acceptance movement are seen as an obstacle to convincing people weight-loss is in their best interest. Political intervention Food labels In the USA, food labels are required by the Food and Drug Administration (FDA) so consumers can make an informed choice about the food they eat. However, according to Obesity Action, foods sold in restaurants, hospital cafeterias and airplanes ,or sold by food-service vendors (including vending machines) or food shipped in bulk (e.g. that which may be shipped to a restaurant for preparation) are exempt from labelling. Another problem is people have to become active readers of the information and understand what impact the various chemicals and additives have. Otherwise, the labels are meaningless. Zoning Laws which govern where fast food outlets can open are under the control of national and local governments. Mair et al. (2005) state that wealthier neighbourhoods have more than three times as many supermarkets as the poorest neighbourhoods. Supermarkets have been linked with healthier diets as a greater range of food is available. However the residents of poor neighbourhoods have less access to private transportation, thereby limiting their chances of visiting places with healthier food available. Grass roots movements The USA comes in for criticism as a result of the high levels of obesity but it is also a source of a significant number of community-based organizations who aim to benefit people – often overcoming political or corporate power in order to do so. Groups such as the Campaign to End Obesity, Two © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com 5 Angry Moms, Queen of Hearts Foundation, National Action Against Obesity (NAAO) and Obesity Action have made a significant contribution to the community landscape via media appearances, school visits and local organizing. According to Otto and Aratani (2006) many school districts in the USA have now banned soft drinks, junk foods and sweets from school vending machines and cafeterias in response to pressure from parents and anti-obesity groups. Treatments Dieting Dieting is associated with a food programme designed to limit energy intake to a level below the rate of energy use. This results in weight loss because the body uses energy from stored fat. However, this cannot be maintained indefinitely. At some point, the individual has to balance their energy intake with energy use. This is achieved by a healthy diet with regular exercise in order to maintain the body weight at a constant level. A person should never engage in extreme weight loss behaviour without first consulting a medical professional. Geissler and Powers (2005) argue the key to weight loss is new habits associated with food and exercise. A healthy diet is not the same as dieting. Weight loss trials with diets invariably work better in tightly controlled environments where clinicians can control what people eat. Geissler and Powers (2005) argue high degrees of compliance and motivation, and a willingness to accept new diets and lifestyles are needed for the dieting process to be a success. These are often difficult to achieve and dieters can be dishonest about what they eat. To improve adherence, consideration should always be given to an individual’s food preferences as well as educational and socio-economic circumstances. Achieving behavioural as well as cognitive change – seeing food in a new way and understanding the challenges – is the key to success with such weight-loss programmes. There are many types of diet. Very low-energy diets (VLEDs) aim to supply very little energy (in the form of calories) but provide all the essential nutrients. The calorie count is usually set at approximately 800 calories a day. However, reducing energy content so greatly requires increased nutritional density and this can be difficult to achieve with natural food. It should also be noted: VLED diets should never be entered into without strict medical supervision. Low-energy diets (LEDs) set the calorie count between 800–1500 calories per day and thus allow for greater use of natural foods. Weight loss is less significant than with VLEDs but the long-term gains are greater as they introduce the individual to healthy, natural food and set habits and 6 © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com routines for greater long-term health. Low-fat diets (LFDs) reduce fat content but promote protein, complex carbohydrates and fibre. LFDs have been shown to be less effective than LEDs for obese patients (e.g. Geissler and Powers, 2005) but are still effective for overweight people. Low-carbohydrate diets (LCDs) reduce carbohydrate intake but promote high levels of protein consumption. They have been shown to induce weight loss in obese patients but pose negative health risks in cardiovascular factors as well as showing poor long-term benefits. Self-help groups Overeaters Anonymous (OA) is an organization similar in structure and intent to Alcoholics Anonymous. A key internalization is for members to admit they are powerless over their desire for food and they embark on a spiritual journey to regain control of their compulsions. Another key element of OA is the notion that excessive weight gain or loss is a symptom of underlying problems and, therefore, the aim of OA is to focus on these issues. Individuals do not report on weight gain or loss, instead members chart their personal, spiritual and emotional progress in the context of food and their wider lives. Westphal and Smith (1996) report an average weight drop of 21 pounds but given the aims of the group, weight reduction cannot be the sole measure of success (not least because about 16% are not overweight but have either anorexia or bulimia). In a qualitative female-only study, Ronel and Libman (2003) note a cognitive shift in world view (which is the true success for OA members) in four domains: experience of self; universal order or God; relationships with others; perception of the problem. The study has limited generalizability to men. OA is not suitable for every obese person. It is only suitable for people who have underlying psychological issues with food and who want to control their problems. Surgery Gastric bypass procedures (GBP) are surgeries leading to a marked reduction in the functional volume of the stomach. They are accompanied by an altered physiological and psychological response to food. There are many variations designed to impact different areas of the digestive tract but most procedures involve reducing the size of the stomach pouch to limit food intake. The resulting weight loss is usually dramatic but the surgery is only considered for those patients who are morbidly obese (in danger of death as a result of their overeating). Positives Surgery reduces the amount of food consumed and makes the patient feel a level of fullness after ingesting only a small amount of food. © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com 7 Dramatic weight loss promotes significant psychological change; most patients are able to actively enjoy participation in family and social activities. Negatives The reduced size of the stomach pouch means a very disciplined approach to food is needed for the rest of the patient’s life. The surgery is a dramatic intervention and complications are common. It has been reported death occurs within one month in 2% of patients. Adams et al. (2007) researched 43 post-operative patients and found that almost all of them tested positive for a hydrogen breath test. This suggests an overgrowth of bacteria in the small intestine. The overgrowth of bacteria will cause the gut ecology to change and will induce nausea and vomiting. Recurring nausea and vomiting will change the rate at which food is absorbed and this exacerbates the vitamin and nutrition deficiencies common in gastric bypass patients. Elkins et al. (2005) found that many who have undergone the surgery suffer from depression in the following month as a result of a change in the role food plays in their emotional outlook. Severe limitations are in force on what the patient can eat and this can cause great emotional strain in individuals who have been used to a certain lifestyle and food choices. However, this should be set in an appropriate context: According to Adams et al. (2007), the long-term mortality rate of gastric bypass patients has been shown to be reduced by up to 40%. This suggests that although some people may be depressed following their operation, they might otherwise not be alive at all. © Pearson Education Ltd 2010. For more information about the Pearson Baccalaureate series please visit www.pearsonbacc.com 8