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Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS Objectives To understand the four components of effective weight control To be familiar with the health problems that are associated with carrying too much body fat To know the principle factors that cause obesity To be able to interpret the recommended fat intake levels for people wanting to lose weight To explain why the body needs to have adequate levels of carbohydrate To explain why get-slim-quick diets don’t work To have an understanding of the popular high protein/low carbohydrate diet and the effects it produces in the body To realise that eating disorders are difficult to treat, professional guidance is highly recommended, Anorexia Nervosa may be life threatening INTRODUCTION People are different shapes and sizes. Trim, chubby, tall, short, everyone looks different. Many people want to have a slim, “ideal” body shape. However, being a healthy weight does not mean that everybody will fit into small clothing sizes. For some people, a healthy weight can be a lot larger, depending on their height and body frame size3. Putting current fashion trends aside, there are very good health reasons for achieving and maintaining a healthy body weight. Those who maintain a healthy body weight are more likely to enjoy a better quality of life and live longer3. Dieting seems to be the most popular indoor sport of women. Hardly a week passes without some new diet making the headlines; most are designed to appeal to women. However, the fact that there are more overweight males than females in Australia has not escaped the notice of those marketing slimming methods. Men as well as women are now being seduced with tales that fibre pills, meal replacement powders and a wide variety of diets will decrease their waistlines4. The worst feature of most of those diets is that they simply do not work. Many also make the would-be slimmer feel so lethargic and irritable that exercise becomes a burden and family and friends begin to wonder what has happened 4. Most diets reduce the number of calories/kilojoules coming into the body from food and drinks. That is fine in theory since excess weight results from an excess of calories/kilojoules. In practice however, if calories/kilojoules are cut back too far, the body reduces the amount of energy it uses to keep its vital processes ticking away. This is the process of metabolism and the rate of any individual’s metabolism can 263 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS vary greatly. If you diet constantly, the body learns to live on fewer calories/kilojoules and thus burns up less energy. It then becomes increasingly easy to regain any lost weight and into the bargain to add a few bonus kilograms of body fat4. Most slimmers know the pattern well. You go on a diet, lose weight, then find the weight seems to miraculously reappear, often with a few bonus bulges. So you try yet another diet, lose some more weight, regain it, and the dieting roundabout goes on and on4. Diets too low in calories/kilojoules can actually make you fat4. Most popular diets are designed for fast weight loss. They extol the joys of seeing a weight loss showing up on the scales but neglect to mention the fact that most of the weight lost is not fat but water. In addition the body’s lean muscle tissue is lost 4. With most weight reduction diets, particularly the popular low carbohydrate diets, the loss of body fat is minimal4. While this unit focuses mainly on diet, it is emphasized that a truly effective weight control program must consider exercise, behaviour change and positive thinking. The degree of emphasis required for each of these four components to combine successfully will vary from one person to another, according to the individual’s needs and situation1. 1. Sensible Eating A basic understanding of nutrition principles and sensible eating is essential to well being, and to sort out the genuine from the fad diet programs offered to the public today. The ‘Your Balanced Eating Plan’ outlined in this unit is an effective system and allows you to plan a well-balanced eating program, tailored to one’s food preferences1. 2. Exercise Regular exercise hastens weight loss and helps to reshape the body – a good way to ‘wake-up’ a sluggish metabolism. It also provides physical fitness, strengthens the heart and blood circulation and also provides psychological and emotional benefits 1. 3. Behaviour Management Behaviour management recognises that many behaviours are significantly associated with overweight, and that learning better eating habits is of vital importance in the control of weight. Habits are formed over many years and they cannot be unlearned overnight1. 4. Positive Thinking and Self-Esteem How you think about your self is central to anything you want to achieve or accomplish in life. Enhancing your self-esteem will provide greater motivation to take the necessary steps to control your weight and adopt a positive, brighter outlook on life1. 264 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS Sensible Dieting Regular Exercise Behaviour Modification Positive Thinking WHAT IS WRONG WITH BEING OVERWEIGHT? There are health problems associated with carrying too much body fat3. Extra weight means more work, especially for the heart. An increase in body weight is accompanied by an increase in the amount of blood vessels through which blood must be pumped. Extra weight also means extra work for the lungs and the digestive system. Excessive weight may put an added burden on the back and legs – it is like carrying around a suitcase weighing 5, 10, or 15 kilograms wherever you go! Overweight people are more likely than people with a healthy weight to develop diabetes, high blood pressure, heart disease, gall bladder disorders and certain types of cancers. Disorders such as sleep apnoea and arthritis may be worsened 3. The good news is that, in people who are carrying around too much body fat, even a modest weight loss may provide a significant decrease in health risks. Weight loss can improve blood sugar control and reduce blood pressure and blood cholesterol levels3. WHERE THE EXCESS WEIGHT IS LOCATED ON THE BODY MAKES A DIFFERENCE2. Moderate amounts of body fat do not compromise health. Just where body fat is stored determines the health risk. It is better to be a pear shape than an apple shape. Excess body fat carried on the hips and thighs is not associated with elevated risk of heart disease, 265 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS hypertension, diabetes and cancer as is the excess fat carried on the upper body or abdomen2. The lower body obesity has less health risks, possibly because the fat on the hips is not well mobilized. The waist/hip ratio measurement may actually be a better predictor of heart disease and risk of death than other measurements of obesity2. OBESITY IS NOT JUST AN ADULT PROBLEM2 We are seeing an increasing number of children and adolescents who are becoming obese. It is estimated that a child has a 50% chance of becoming obese if one parent is obese and a 70 – 80% chance if both parents are obese2. Obesity in children also manifests the same health risks seen in adults such as elevated blood lipids, high blood pressure and impaired glucose tolerance 2. Obesity in teenage years strongly increases the risk of adulthood obesity2. Children should be encouraged to eat a well balanced diet so that they can grow and develop into healthy adults. If your child is overweight for their age and height, the solution is to help balance the energy equation3. You should encourage them to become more active and change the type of foods eaten if these include a lot of fatty fast foods or sugary snacks and drinks 3. Try turning off the television or limiting computer games and encouraging your child to spend more time playing outdoor games, participating in sports and perhaps riding or walking to school if possible3. Putting your child on a restricted diet is not advisable. Encourage your child to make healthier food choices (such as fresh fruit) rather than telling them to eat less food. Aim to hold your child at the current weight over a certain length of time, so that their height can increase and catch up3. WHAT MAKES PEOPLE FAT2? The principle factors causing obesity are over consumption of food and an inadequate energy expenditure. It is a little like your bank account. If you put more money in than you use, you gain. Excess food calories are stored. Even small excesses over a long period of time can lead to obesity2. We may be tempted by a plentiful supply of foods in our home, by advertising of high kilojoule snack foods. Or we may just enjoy eating and drinking3. Sometimes over-eating becomes a way to alleviate boredom, frustration or depression. We may also just eat out of habit3. Modern society has many labour saving devices, which have reduced our day-to-day physical activities. As well, our spare time is often spent in watching television, using the Internet, or doing other activities that do not require us to expend much energy. The latest data has shown that 67% of Australians do little or no exercise each day3. 266 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS Eating too many foods that are high in fats on a regular basis Most people in Australia still eat too much fat. Too much fat in the diet can contribute to weight gain if it is not burnt up as energy by the body. Eating fast foods, preprepared and restaurant meals can make it difficult to control the amount of fat and other nutrients in your diet. This is an important issue as the trend for meals purchased outside the home seems to be increasing3. Percentage of fat in foods. Don’t be fooled by the promotion of foods claiming to have a low percentage of fat. It is the serving size and total grams of fat that count1. For example, whole milk with 3.8% fat sounds low (3.8 g of fat per 100 ml/g of product) but a 250 ml cup contains 9.5 g of fat (and 2 cups contain 19 g fat)1. Ice cream with 10% fat seems high, yet a large scoop (50 g) has only 5 g fat. (Lowfat ice cream has less than 2 g fat per serve)1. Please note: Don’t go home and start eating ice cream every day! Remember to count the grams of fat per serving, or for the total quantity of that particular food you consume in a day, as in the illustration above 1. HOW CAN I LOSE WEIGHT3? There is no quick solution to losing weight permanently. Losing weight is all about getting the right balance between energy intake and energy output 3. To lose weight we need to create an energy deficit. When we eat just as many kilojoules as we use up each day, our body weight remains the same. If more kilojoules are eaten than are used up each day, they are stored as body fat and we may gain weight3. But if fewer kilojoules are eaten than are burnt up we are likely to lose weight. Put simply, for weight loss, energy output needs to be greater than energy intake. This is the underlying principle of a weight loss plan3. Energy Intake Our energy needs vary according to our age, gender, body size, weight and physical activity. The energy we get from food is now measured in units called kilojoules (kJ). (1 calorie = 4.2 kilojoules3.) Fat contains twice as many kilojoules as carbohydrate or protein. So fatty foods are often higher in kilojoules than low-fat alternatives. In addition, the kilojoules from fats are stored more readily as body fat than the kilojoules from carbohydrates and proteins. In fact, it takes eight times as much energy for your body to convert carbohydrates into body fat than it dies to convert dietary fat into body fat. Reducing the amount of fat in your diet is a major aspect of weight reduction3. However at the end of a typical day, any excess energy (from either fat, sugar, alcohol or another source) that hasn’t been used by your body is converted into body fat3. While too much fat in the diet can increase our level of body fat, it is important to realise that fat is a necessary nutrient. Dietary fats supply essential fatty acids, such 267 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS as omega-3 fats and the fat-soluble vitamins A, D, E, and K that our bodies need to maintain good health. Fat also adds flavour and texture to our foods3. Recommended fat intakes for men and women Health authorities recommend that daily fat intake should contribute 30% or less of total daily kilojoule (or calorie) intake. This is equivalent to 40 – 60 grams of total fat per day for men, 30 – 50 grams per day for women and children and 70 grams per day for very active teenagers and adults3. However for those wanting to lose weight (unless they are teenagers or very active), it is recommended that daily fat intake be kept to 40 – 50 grams for men and 30 – 40 grams for women3. Energy Output The energy we use for physical activity and maintaining our body-s systems is also measured in kilojoules. Exercise is a very important aspect of maintaining a healthy weight. Exercise burns up the energy provided by food and increases the rate at which energy is used for the rest of the day, (basal metabolic rate) thereby helping to reduce fat stores. Exercise also helps to relieve boredom, stress and frustration – factors which often lead to overeating3. Exercise equivalents of food energy1 Food cals kj Gardening (mins) Brisk walking (mins) Fast running (mins) 2 plain biscuits 1 can soft drink 100 gram chocolate 1 scoop ice-cream 1 meat pie small packet of chips 72 180 525 90 500 150 300 750 2200 375 2090 625 22 56 163 28 155 46 17 42 122 21 116 35 7 16 48 8 45 13 Example: You would need to walk briskly for 2 hours to burn up a chocolate bar 1. DO GENES HAVE ANY INFLUENCE? The genes you inherit do play a role in determining whether you will have the tendency to gain weight and whether you are likely to develop associated diseases, such as diabetes and heart disease3. However, your lifestyle can strongly influence how your genes express themselves. Therefore, what you eat and how much you exercise is still very important 3. WHY THE ‘GET-SLIM-QUICK’ DIETS DON’T WORK Diets offering shortcuts rarely work in the long term. Just as excess body fat does not appear overnight, it will not disappear quickly either3. 268 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS Crash diets fail because quick weight loss is usually taken from muscle tissue and water stores instead of body fat. The body can restore these supplies in a very short time. Once a normal eating pattern is resumed, the dieter is back to square one – sometimes with a few extra kilos for their efforts3. Health authorities consider an average weight loss of ½ to 1 kilogram each week to be healthy and achievable for people who are overweight3. High protein/low carbohydrate diets (popular in the community at present and often recommended by slimming clinics at considerable financial cost)4 For many years, most of the popular weight loss diets have been formulated on the premise that proteins won’t make you fat. Carbohydrates on the other hand have been painted as the villains, many people believing that any successful slimmer must strive to avoid them4. Certainly the body needs protein, since all body cells, including muscles and hormones are made of it. However, there are no special virtues in eating it beyond the body’s ordinary requirements. Nor does it mean that extra protein will be magically absorbed into better and bigger biceps4. Many of the world’s most famous ‘diet doctors’ used (and still prescribe) high protein diets for their overweight clients. These so-called slimming diets are low in carbohydrate. If you try one of these high protein/low carbohydrate diets for a few days and then step on the scales, you will see why the slimming regime has so many devotees among the ‘diet doctors’ and their clients4. By omitting carbohydrate and increasing protein, you will lose weight. This drop in the reading on the scales has been responsible for many of the foolish and dangerous diets which have dominated the lives of so many overweight people for many years4. Only recently has the reason for the weight loss, which accompanies the high protein/low carbohydrate diet, been exposed as well as its dangers4. When protein is increased and carbohydrate is decreased, the body responds by losing water. This shows up in a loss of weight. However, you are not necessarily losing body fat at all – only water. Since the body is more than half water, a drop in the body’s normal fluid content will appear as a loss of body weight4. Unfortunately, however, it is not water which overweight people need to lose, but fat. A further problem also develops. A low carbohydrate diet causes an inevitable loss of some of the body’s lean tissue. Loss of body fat (the stuff we really want to get rid of) is minimal4. The problems of too little carbohydrate To function properly, the body must have adequate levels of carbohydrate, in the form of glucose, in the blood. The brain for example, cannot use any other fuel but glucose, and has almost no stores within it self. Other vital organs such as the heart, liver and kidneys also need glucose as their energy source4. 269 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS The body does keep some stores of glucose in the form of glycogen in the liver and the muscles. When carbohydrate intake is low, the glycogen stores are mobilised and converted into glucose. Glycogen is stored in the body with a lot of water, so any time you use up your glycogen, a lot of water is released. There is no mystery to the loss of weight, which appears with a decrease in the carbohydrate content of the diet – it is simply due to the loss of water associated with the loss of glycogen 4. Once the glycogen stores are used, the body will break down some of its muscle tissue to produce glucose to keep the vital organs functioning. Fats can be burned to provide energy for muscles, but they cannot provide the glucose needed by the vital organs. Since fats cannot be converted to glucose, some loss of lean tissue will occur with low carbohydrate diets4. The fact that most of the rapid weight loss associated with cutting back on carbohydrates is largely water rather than fat is never mentioned. After a few days, the body will gradually replenish its water supplies and the would-be slimmer is faced with the inevitable return of the lost weight4. What is concerning about this situation is that most slimmers will automatically blame themselves, feeling that they were unable even to lose weight with a strict diet. In fact it’s not the dieter who is at fault it’s the diet4. The added problem of too much fat Any diet, which is low in carbohydrate, will automatically be high in protein and fat. The high protein content is emphasised, but very little is said about the high percentage of fats, which almost inevitably accompanies the protein 4. There is no doubt that fats most certainly are the problem, whether there are carbohydrates in the diet or not. The high fat diet so common in the Western world is at least partly responsible for many of our most common health problems, including obesity, coronary heart disease, gallstones, diabetes and certain types of cancer 4. Specific dynamic action Some of the proponents of the high protein slimming diets quote a theory called the “Specific dynamic action” of proteins. This theory has some basis, since pure proteins do have some ability to stimulate the body’s metabolism. However, this applies only to pure proteins and not to the same extent when the protein is in combination with fat and carbohydrate. In practice, eating any food will stimulate the body to burn up energy for its metabolism; the effect of protein is not significantly higher than that of a mixed diet4. Ketosis Some of the more modern protein promoters have extolled the virtues of a high protein/high fat diet to produce a condition known as ketosis. This state occurs within the body during fasting or starvation. It is also present when the diet lacks carbohydrates and thus consists almost entirely of proteins and fats4. Every tissue in the body normally uses glucose as its source of energy. This comes from carbohydrates in the diet. If the diet is deficient in carbohydrates, protein can be 270 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS broken down to glucose. Fats can never be converted into glucose, but they can still be used as fuel for muscles. However, the body’s nervous system, brain and vital organs must have glucose as a source of energy; the fats cannot be burned properly without some glucose being present. The body tries to obtain some glucose by breaking down some of the protein in the muscles4. While this process is occurring and the fats are being incompletely burned, substances called ketones are produced. As the body is making these it is in a state called ketosis. The ketones are excreted in the urine and on the breath. You can often detect ketones with an acetone-like smell on the breath of someone whose diet is deficient in carbohydrates. You can buy special testing sticks to dip in your urine to tell if the body is in a state of ketosis. These are usually used as a warning for people with diabetes4. Ketosis is an unhealthy condition. The partially burned fats can damage the kidneys and a dangerous condition, acidosis, can develop. Diets, which cause acidosis, can also cause uric acid in the blood to rise to levels, which may precipitate an attack of gout. If a pregnant woman is in a state of ketosis, her blood glucose levels will be so low that brain damage to her child may result. Ketosis is not only an undesirable and hazardous condition, but is also most unpleasant, with side effects including headaches, dizziness, nausea as well as bad-smelling breath4. A HEALTHY APPROACH TO LOSING WEIGHT Food is a basic necessity of life and it is also one of life’s pleasures. Both these points need to be kept in mind if you’re thinking about losing weight 3. A good eating plan: Ensures that the food necessary for good health is included in the diet. Allows for the enjoyment of eating out on special occasions and with the family. Provides a basis by which body weight may be kept at a desirable level in the future3. Losing weight is not something you only work on now and then – it needs to be ongoing. Try not to reach for food when you are lonely, bored, depressed, frustrated or anxious. Instead, go for a walk, ring or visit a friend, read a book or start a special project around the house or garden. If you do snack or graze, choose low fat, fibrefilled snacks3. Concentrate on your food when you are eating, avoid watching TV or reading. Slow your pace of eating and enjoy every bite. Avoid second helpings or preparing extras3. Positive thinking Make maintaining a healthy weight your goal. By making simple lifestyle changes you will be able to enjoy good health3! 271 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS EATING DISORDERS Eating disorders disturb what might be referred to as ‘normal eating’; though it needs to be recognised that many very different eating patterns can be regarded as ‘normal’. One large meal, and/or several small meals throughout the day can all constitute ‘normal eating’, providing satisfaction and enjoyment to the individual5. Eating disorders are relatively common in Australia and are distressing to those who suffer them. It is believed that strong social pressure to achieve the socially favourable slim body shape has a role in the development in susceptible individuals of eating disorders and associated problems of anorexia nervosa and bulimia nervosa. Those providing advice on diets to avoid gain or to achieve weight loss must be aware of the potential to initiate eating disorders. Every effort must be made to give a realistic view of what can be achieved5. THE PRINCIPAL EATING DISORDERS Anorexia Nervosa is a psychological disorder, most usually affecting teenage girls. The first recorded case was in 1684. Those affected persists in trying to lose weight even though they are already very underweight. The term anorexia refers to lack of appetite. Temporary loss of appetite is common in illness or with anxiety, but in anorexia nervosa, the individual determinedly goes on trying to lose weight despite family and medical advice. No known physical disease is involved5. The characteristics are as follows: 1. Low body weight Those affected are 15% or more below normal or expected body weight 5. 2. Food avoidance and faddism Those affected avoid eating normal meals. They particularly avoid any foods they consider to be fattening, including especially foods with fats and sugar. They will tend to eat salads and green vegetables but may avoid potatoes. Often they will invent excuses for not eating, and on occasions, they lie about their eating. They will talk freely about food and will prepare meals for others, but avoid eating the food themselves5. 3. Excessive concern about being fat Despite their thinness, those affected display concern about being fat. They are unable to accept that they are thin and need to gain weight rather than lose it. Whatever their weight is they generally want to lose a little bit more. They may wear loose clothes to disguise their thinness5. 4. Distorted perception of body size Frequently those affected indicate that they perceive their body size to be greater than it is5. 272 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS 5. Use of purging Commonly those affected use purging to attempt a greater weight loss. Purging refers to self-indulgent vomiting or overuse of laxatives or other medications, though they are generally reluctant to admit this5. 6. Excessive exercise Those affected recognise that weight loss can be achieved by increased energy expenditure as well as by restricted food intake and they commonly indulge in long periods of exercise5. Causes and Management of Anorexia Nervosa There are a number of theories about the cause of anorexia nervosa but there is no clear understanding of its origin. The condition usually begins with some form of dieting. Dieting is extremely popular yet only a small proportion of dieters develop anorexia nervosa5. The psychology of anorexia nervosa appears to be closely related to the obsessive-compulsive group of behaviours. One psychological basis suggested is an attempt to achieve control over personal relationships, while an alternative proposes some sort of addiction to dieting, related perhaps to the Western cultural approval of the thin body shape5. Severe anorexia nervosa is a serious condition and parents of affected children should not delay in seeking help. Early management is more likely to be successful. The longer it persists the more likely the problem is to be become entrenched. Because the problem is psychological in origin, management centres on counselling and cognitive behaviour therapy. It is highly recommended that people affected with eating disorders be referred to a psychologist or a psychiatrist who specialises is this area5. Bulimia Nervosa is an eating disorder closely related to anorexia nervosa and expressed through a range of disturbed behaviours. In bulimia nervosa the affected person is usually overweight to some degree and is trying very hard, or has tried, to lose weight by restricting food intake. Natural hunger has overcome the resolve to diet and the person begins ‘binge eating’. This refers to eating an exceptionally large amount of food in a period of an hour or two. After the binge the person is likely to feel depressed at having broken the diet and not being unable to get their weight down to the level they desire. In a desperate attempt to prevent the inevitable weight gain they may resort to self-induced vomiting or laxative abuse5. After this event they may resolve to restrict their eating and only eat small amounts of food over the next day or two; hunger grows to the point where another binge becomes inevitable and the whole cycle is repeated. The life of a bulimic individual becomes haphazard and unhappy, with no fixed meal pattern, difficulties around eating, and often depression or other psychological disturbance5. 273 Unit 19 OBESITY, WEIGHT MANAGEMENT AND EATING DISORDERS Prevalence of bulimia nervosa Individuals who develop bulimia nervosa are generally older than those who develop anorexia nervosa; typically they are in their late teens or early twenties, and from the middle to high socioeconomic group. The condition is thought to be more common than anorexia nervosa; possibly affecting 10% or more of the susceptible group5. Management of bulimia nervosa Management, as with anorexia nervosa, is based on psychological counselling. Because those affected are also likely to be affected by other psychological disturbances, it is important that counselling be given by a psychologist or psychiatrist5. CONCLUSION It is important that the problem of anorexia and bulimia nervosa be recognised in the community by parents, teachers, doctors, dietitians and other professionals working with young people. It is a challenging problem because, on the one hand, the Australian population is becoming fatter and fatness is associated with increased risk of ill health, but on the other hand, increased emphasis on the importance of having a slim body may increase the likelihood of initiating disordered eating5. The most effective approach is to educate children in their teenage years regarding normal body composition and the role of diet and exercise, and to assist them to have a realistic view of their own weight. With this in mind the young man or woman can adopt the health behaviours they choose without falling into the trap of striving and failing to meet unrealistic expectations5. REFERENCES: 1. Borushek A; ALLAN BORUSHEK’S DIET MANUAL Family Health Publications West Perth. 1988:2, 43, 80 2. Craig W; NUTRITION AND WELLNESS Golden Harvest Books Berrien Springs Michigan. 1999:157-166 3. Sanitarium Nutrition Education Service; HEALTHY WEIGHT HEALTHY BODY Sanitarium Health Food Company February 1999 4. Stanton R; THE ART OF SENSIBLE EATING Collins Publishers 1988: 7, 14-17 5. Wahlqvist M. L; FOOD AND NUTRITION - Australia and New Zealand 2nd Edition Allen & Unwin Pty Ltd Crows Nest NSW. 2002:406-411 274