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Eating disorders involve a serious disturbance in eating behaviour (either eating too much or too little).1 This chapter addresses anorexia nervosa, bulimia nervosa and binge eating disorder.
Eating disorders are unhealthy eating patterns that take on a life of their own. They are not a function of will. While the voluntary eating of smaller- or larger-than-usual portions of food is common, for some individuals this develops into a compulsion.
Individuals with anorexia nervosa cannot maintain a minimally normal body weight, carry an intense fear of gaining weight, and have a distorted perception of the shape or size of their bodies.2
Individuals with bulimia nervosa undertake binge eating and then use compensatory methods to prevent weight gain, such as induced vomiting, excessive exercise or laxative abuse. They also place excessive importance on body shape and weight. In order for a diagnosis of bulimia nervosa, the binge eating and compensatory behaviours must occur, on average, at least twice a week for three months.3
A diagnosis of binge eating disorder is made if the binge eating is not followed by some compensatory behaviour, such as vomiting, excessive exercise or laxative abuse. This disorder is often associated with obesity.
According to Statistics Canada's 2002 Mental Health and Well-being Survey (Canadian Community Health Survey (CCHS), Cycle 1.2), 0.5% of Canadians aged 15 years and over reported that they had been diagnosed with an eating disorder in the previous 12 months. Through a separate set of questions, the survey also found that 1.7% of Canadians aged 15 and over reported symptoms that met the 12-month criteria for an eating attitude problem.
Anorexia nervosa and bulimia nervosa are most predominant among adolescent girls and young women; 5-15% of anorexia nervosa and bulimia nervosa and 40% of binge eating disorders are among boys or men, however.4 5 In most cases, binge eating disorder onsets during adolescence or young adulthood.
According to the 2002 Mental Health and Well- being Survey (CCHS 1.2), women were more likely than men to report an eating disorder: 0.8% versus 0.2%, respectively. More women than men met the criteria for an eating attitude problem: 2.9% of women versus 0.5% of men. Among young women (15–24 years), 1.5% reported that they had an eating disorder. Two percent reported symptoms that met the criteria for an eating attitude problem.
Approximately 3% of women will be affected by an eating disorder in their lifetime.6Between 0.5% and 3.7% of women will develop anorexia nervosa during their lifetime,7 8 and between 1.1% and 4.2% will develop bulimia.9 10
Binge eating disorder affects about 2% of the population.11
Individuals with anorexia nervosa and bulimia may recover after a single episode of the disorder. Other individuals may have a fluctuating pattern of weight gain and relapse while others will continue to have issues with food and weight throughout their lives. Poorer long-term outcomes are associated with a lifetime history of problematic substance use at the time of diagnosis and longer duration of symptoms before diagnosis.12
Individuals with anorexia nervosa and bulimia may develop serious physical problems that can lead to death, such as heart conditions, electrolyte imbalance and kidney failure. Suicide is also a possible outcome.
Even after the acute episode has been resolved, eating disorders may cause long-term psychological, social and health problems.13
An eating disorder causes young people to miss school, work and recreation activities. The physical weakness associated with the illness also seriously affects their social interaction with friends and their involvement in life in general. Friends also have difficulty knowing how to react and how to help.
Families of individuals with eating disorders also live under great stress. They may blame themselves, feel anxious about their loved one's future, worry that the family member will die or face the stigma associated with having a child with a mental illness. Parents, especially, experience the tension between their natural protective instinct to force healthy behaviours on the child (which can often make the situation worse) and the child's need to take control over his/her illness and health.
The stigma associated with eating disorders comes from the lack of understanding that an eating disorder is a problematic coping strategy.
The mistaken impression among many is that parents are to blame if a child has anorexia nervosa or bulimia. This stigmatization isolates parents from their peers and other family members.
The individual with an eating disorder may feel shame about weight fluctuations. Stigma is also associated with the presumption of a loss of control around eating, stealing binge food or bingeing in secret.
Individuals with binge eating disorder who are obese contend with negative societal attitudes toward obesity, which tend to make them feel isolated. The loss of self-esteem also exacerbates the illness.
Eating disorders are complex syndromes strongly associated with other mental illnesses such as mood, personality and anxiety disorders. The development of an eating disorder is believed to result from a combination of biological, psychological and social factors. In addition, the secondary effects of the maladaptive eating practices likely contribute to the disorder.17 (Table 7-1)
Eating disorders are more frequent in females. In particular, teen girls and young women are at higher risk for disordered eating, shape and weight preoccupation, and dieting behaviour.
Adolescents go through major hormonal and physical changes during puberty that often result in a heightened awareness and altered perception of their body image. Images of female beauty portrayed in magazines and on TV are often unrealistic and unattainable. Media attention on the "ideal" weight and size for both females and males may foster a negative self- perception when those ideals are not achieved.
According to the World Health Organization's 2002 Health Behaviour in School-aged Children (HBSC) Canadian survey, approximately 60% of students from Grades 6 to 10 reported that their body image was just right: 59% of males and 56% of females. Almost 1 in 3 (31%) young women thought that they were too fat. The proportion increased with age, so that by Grade 10, 44% felt that they were too fat. (Figure 7-1). The proportion is much lower among young men (22% overall) and varied only slightly with age.
By comparison, boys across all grades were more likely than girls to indicate that they were too thin rather than too fat. (Figure 7-2) This proportion increased during the early high school years.
Unrealistic perceptions of body size may carry various health risks. These range from inappropriate attempts at dieting (which can lead to anorexia nervosa or bulimia) to failure to recognize and manage weight gain. Psychologically, perceiving that one's body is outside the "normal" range or having unfavourable body image may lead to low self- esteem and self-confidence.
"While the media is not the cause of eating disorders, it is a significant sociocultural determinant of why so many people (particularly women) convey their distress through the language and behaviour of an eating disorder."18
According to the 2002 HBSC Canadian survey, the proportion of young women who indicated that they were on a diet to lose weight was 2.2 times greater than the proportion of young men (20% versus 9%, respectively). This was consistent across all grade levels. (Figure 7-3) By Grades 9 and 10, over 25% of young women were on a diet at the time of the survey.
Preventive interventions are generally targeted at school age children, professional schools with specific high risk populations (such as ballet students, female athletes, fashion models, culinary students), or young girls and women showing unhealthy eating behaviours. Studies of the effectiveness of various interventions show mixed results. More research is needed to study risk factors; to identify factors that characterize successful interventions; and to predict which interventions will be effective on particular populations.19
Eating disorders can be treated and healthy weight restored. Treatment is most effective if started in the early stages of the disorder. Routine assessment of teens and young adults for the signs of an eating disorder can help the early identification of those who have a problem.
Treatment of eating dis20,21orders has changed dramatically over time. Nutritional stabilization has replaced the former practice that emphasized long-term psychotherapy and potentially harmful medications. Once an individual's nutrition status has improved, a variety of psychotherapies (cognitive-analytical, family and cognitive-behavioural) can improve the illness. Young women who are not afraid of weight gain and who do not have a distorted body image have a better prognosis.22
Eating disorder behaviours are very valuable for the individual: weight loss can provide a sense of accomplishment; or binge-and-purge episodes can help in managing or avoiding difficult emotions. As a result, motivational issues must be addressed throughout treatment to ensure that it matches a client's readiness for change.23 24
A comprehensive treatment plan should include an investigation of problematic substance use and the experience of trauma. Treating co- existing mental illnesses, such as depression, anxiety and alcoholism, is also essential.
Anti-depressants have been shown to be useful in the treatment of bulimia nervosa.25 Some medications are also useful for treating binge eating disorder. Unfortunately, effective drugs for treating anorexia nervosa have not been identified.
For people who have been ill for many years with anorexia nervosa, brief time-limited admissions to hospital with supportive psychotherapy can help stabilize weight loss and treat metabolic complications.
Hospitalization rates for eating disorders are highest among young women in the 15–19 year-old age group. (Figure 7-4) The next highest rates are among the 10–14 and 20–24 year-old age groups.
The National Eating Disorders Information Centre (www.nedic.ca ) offers several suggestions for family and friends of an individual who is experiencing food and weight problems. Suggestions include: