Nutrition Intervention in the Treatment of Anorexia Nervosa, Bulimia Nervosa, and Eating Disorder Not Otherwise Specified (EDNOS) - Treatment of Anorexia Nervosa

Written by HealthyPlace.com Staff Writer

BULIMIA NERVOSA

Bulimia Nervosa (BN) occurs in approximately 2 to 5% of the population. Most patients with BN tend to be of normal weight or moderately overweight and therefore are often undetectable by appearance alone. The average onset of BN occurs between mid-adolescence and the late 20s with a great diversity of socioeconomic status. A full syndrome of BN is rare in the first decade of life. A biopsychosocial model seems best for explaining the etiology of BN (55). The individual at risk for the disorder may have a biological vulnerability to depression that is exacerbated by a chaotic and conflicting family and social role expectations. Society's emphasis on thinness often helps the person identify weight loss as the solution. Dieting then leads to binging, and the cyclical disorder begins (56,57). A subgroup of these patients exists where the binging proceeds dieting. This group tends to be of a higher body weight (58). The patient with BN has an eating pattern which is typically chaotic although rules of what should be eaten, how much and what constitutes good and bad foods occupy the thought process for the majority of the patient's day. Although the amount of food consumed that is labeled a binge episode is subjective, the criteria for bulimia nervosa requires other measures such as the feeling of out-of-control behavior during the bingeing (See Figure).

Although the diagnostic criteria for this disorder focuses on the binge/purge behavior, much of the time the person with BN is restricting her/his diet. The dietary restriction can be the physiological or psychological trigger to subsequent binge eating. Also, the trauma of breaking rules by eating something other than what was intended or more than what was intended may lead to self-destructive binge-eating behavior. Any subjective or objective sensation of stomach fullness may trigger the person to purge. Common purging methods consist of selfinduced vomiting with or without the use of syrup of ipecac, laxative use, diuretic use, and excessive exercise. Once purged, the patient may feel some initial relief; however, this is often followed by guilt and shame. Resuming normal eating commonly leads to gastrointestinal complaints such as bloating, constipation and flatulence. This physical discomfort as well as the guilt from binging often results in a cyclical pattern as the patient tries to get back on track by restricting once again. Although the focus is on the food, the binge/purge behavior is often a means for the person to regulate and manage emotions and to medicate psychological pain (59).

Medical Symptoms

In the initial assessment, it is important to assess and evaluate for medical conditions that may play a role in the purging behavior. Conditions such as esophageal reflux disease (GERD) and helicobacter pylori may increase the pain and the need for the patient to vomit. Interventions for these conditions may help in reducing the vomiting and allow the treatment for BN to be more focused. Nutritional abnormalities for patients with BN depend on the amount of restriction during the non-binge episodes. It is important to note that purging behaviors do not completely prevent the utilization of calories from the binge; an average retention of 1200 calories occurs from binges of various sizes and contents (60,61).

Muscle weakness, fatigue, cardiac arrhythmias, dehydration and electrolyte imbalance can be caused by purging, especially self-induced vomiting and laxative abuse. It is common to see hypokalemia and hypochloremic alkalosis as well as gastrointestinal problems involving the stomach and esophagus. Dental erosion from self-induced vomiting can be quite serious. Although laxatives are used to purge calories, they are quite ineffective. Chronic ipecac use has been shown to cause skeletal myopathy, electrocardiographic changes and cardiomyopathy with consequent congestive heart failure, arrhythmia and sudden death (2).

Medical and Nutritional Management of Bulimia Nervosa As with AN, interdisciplinary team management is essential to care. The majority of patients with BN are treated in an outpatient or partial hospitalization setting. Indications for inpatient hospitalization include severe disabling symptoms that are unresponsive to outpatient treatment or additional medical problems such as uncontrolled vomiting, severe laxative abuse withdrawal, metabolic abnormalities or vital sign changes, suicidal ideations, or severe, concurrent substance abuse (12).

The registered dietitian's main role is to help develop an eating plan to help normalize eating for the patient with BN. The registered dietitian assists in the medical management of patients through the monitoring of electrolytes, vital signs, and weight and monitors intake and behaviors, which sometimes allows for preventive interventions before biochemical index change. Most patients with BN desire some amount of weight loss at the beginning of treatment. It is not uncommon to hear patients say that they want to get well but they also want to lose the number of pounds that they feel is above what they should weigh. It is important to communicate to the patient that it is incompatible to diet and recover from the eating disorder at the same time. They must understand that the primary goal of intervention is to normalize eating patterns. Any weight loss that is achieved would occur as a result of a normalized eating plan and the elimination of binging. Helping patients combat food myths often requires specialized nutrition knowledge. The registered dietitian is uniquely qualified to provide scientific nutrition education (62). Given that there are so many fad diets and fallacies about nutrition, it is not uncommon for other members of the treatment team to be confused by the nutrition fallacies. Whenever possible, it is suggested that either formal or informal basic nutrition education inservices be provided for the treatment team.