Anorexia Nervosa

Jun 10, 2019 | 0 comments

Jun 10, 2019 | Miscellaneous | 0 comments

Anorexia Nervosa Nutritional Rehabilitation


Anorexia nervosa (AN) is a frequent and complex intractable illness, which has an unknown etiology that is habitually disabling and chronic. It has the characteristics of aberrant behaviors of feeding, an extreme pursuit of emaciation and thinness as well as distortions of body image. Notably, the onset of AN tends to happen in females in the adolescent period and about 0.7 percent of this group can be affected, whereas the present lifetime estimate prevalence of AN is 0.3 percent. There are two subtypes of eating-associated AN behaviors. The first type is the restricting-type anorexics (R-AN) whereby the victim loses weight purely through exercising and dieting with bing purging or eating. The second type is the binge-eating or purging-type anorexics (BP-AN), whereby the victims also restrict their intake of food and exercise to lose weight, although periodically are involved in binge eating or purging. This research paper aims to make a summary of what is known about the nutritional and caloric requirements in gaining and maintaining weight in patients. It also examines the urgent requirement to expand significant nutritional knowledge relating to patients in establishing evidenced regarded treatments.

Notably, AN is frequently related to illness denial and treatment resistance. As a result, it is hard to engage people suffering from AN in treatment, involving weight normalization, and nutritional restoration. The permanent restrictive malnutrition and eating led to pervasive disturbances of various organ systems such as endocrine disorders, gastrointestinal and cardiovascular complications, and other various metabolic alterations (Garner and Garfinkel, 2016). Hence, nutrition restoration is the main treatment element due to the weight restoration need for avoiding severe physical complications as well as improving cognitive function in making psychological interventions effective and useful.

People with AN do not complete their treatment programs and often relapse due to continued eating behaviors that are harmful. These people tend to be frequently hospitalized and have high chronicity and mortality. Regardless of them experiencing denial and resistance, there are other different contributory factors. To start with, collected data has suggested that people with AN, specifically, the restricting type, face difficulty while eating because AN generates a profound anxiety sense, instead of reward or pleasure. However, there is current evidence the AN patients have neural mechanisms alterations that generally activate the food consumption drive when hungry or starved (Bruch, 2014). Additionally, patients habitually consume diets with vegetables, which results in low calorie, and also consume meals with low fat that are insufficient daily calorie, essential amino acids, and fatty acid requirements. Even in patients that have undergone weight restoration, abnormal behaviors of eating often persist, as a limited variety of diet was examined to be related to poor outcomes. From a clinical perspective, AN victims seem to be hypermetabolic in weight restoration in such a way that they require an increased intake of calories in maintaining a safe recovery in weight. Nonetheless, the tendency of returning to restrictive habits of eating after hospitalizations involves the increased caloric requirement need as a result of the hypermetabolic state.

Importantly, there is little available empirical data in defining optimum choices of food for the restoration of weight and addressing the associated challenges with weight gain rate and weight maintenance. This has impacted the development of guidelines of evidence-based therapy on nutritional rehabilitation in AN.

AN Behavior of Eating

It is well documented that AN patients, contrary to healthy controls, tend to significantly eat low calories in restricting the caloric intake and avoid calorie-dense foods. Individuals have various unusual behaviors of eating such as irregular and slow eating, vegetarianism, and choosing from a narrow food range. More interesting, it has been established that these patterns of an eating disorder are witnessed before the illness starts. Different scholars have shown how premorbid individuals’ daily diets are basically less calorie dense compared to those with healthy controls. Eating only vegetarian food of low energy density as a losing weight means may result to various problems like essential nutrient intake deficit in cases where proteins from plant-based sources are not well balanced leading to lack of some essential amino acids as well as an inadequate synthesis of proteins in the human body (Sullivian, 2015). Noteworthy, voluntary restriction in calorie in lean people, including ingestion of 75 percent of daily calorie requirements, to improve longevity and slow aging, is not related with essential nutrient intake severe deficit, most likely as a result of diverse protein adequate amounts inclusion and diet prescription micronutrients (Russell, 2017.

About different studies examining food consumption differences between a patient of AN and healthy controls, AN adolescents had the lowest intake of all fat types, higher intake in fiber, and normal carbohydrates and proteins. Besides, they showed a lower fat intake although they had a higher carbohydrate intake with no protein difference found involving a naturalistic laboratory design of the study. Different studies on adult patients of AN show similarity in adolescent data having micronutrients and macronutrient deficiencies. Other studies have shown how people highly avoid fatty foods and how there is a lower intake in total energy in AN compared to healthy controls. In regards to carbohydrates, other studies have documented that diets increased intake percentage, although other studies have not confirmed the same data. Similarly, protein intake data percentage in AN victims was inconsistent, although some studies showed an increase in percentage intake and others showed a percentage decrease.

Furthermore, reports have been written that patients of AN have a tendency of choosing similar foods in every meal, and these behaviors of eating persist during recovery in the short-term, with dense food with low energy and limited variety being related to a poor outcome. Recently, it has been shown that high-density scores in dietary energy are highly predictive for better outcomes compared to overall caloric intake. Remarkably, a study on food intake follow-up for one year after a patient was discharged from the hospital revealed that AN individuals most of the time revert to low intake in calorie and pathological eating. Considering actual intake in calories, considerations should make that healthy young or adult women always eat almost 30 kilograms/kilocalories per day (kcal/kg/day), with a 20 to 40 kcal/kg/day range (Garner, Olmstead, and Polivy, 2013). To women who are 50 kg, their consumption ranges almost 1,500 kcal/ day with a normal range of 1,000 to 2,000 kcal/ day. In the present experience, individuals face difficulties in eating more than 10 to 20 kcal/kg daily (Suilivian, 2015).

What is known on AN weight restoration?

Weight and nutritional restoration are the main components in treatment programs. Regardless of the emphasis, little research has been done in the AN section. This is notable when referring to considerable re-feeding literature on forced starvation or a long fast in individuals that are non-AN. Markedly, both the National Institute for Health and Care Excellence (NICE) and American Psychological Association (APA) guidelines have specified clearly how the first treatment goal is through weight restoration (Brumberg, 2018). Nonetheless, the guidelines of APA do not give specifications on caloric guidelines on outpatients’ intake, although they give suggestions on hospitalization-related amounts, without mentioning the quality and quantity of nutrients most important in achieving treatment goals. Similarly, the guidelines of NICE report the weight gain in weeks that are expected in AN outpatients and inpatients, although particular prescriptions in calorie are not involved. Remarkably, the literature on the significance of AN weight gain involves re-feeding in resistant and severe AN cases, clinical improvement needing a caloric intake, micronutrient alterations and deficiencies effects on adolescent victims, inpatient treatments, and re-feeding risks. Nevertheless, relatively less is documented on moderate essential nutrients or the food products that are most important in replenishing these essential nutrients. The issue is important because AN dietary choice is directed by vegetarian-based preference, low food type energy-dense diet, instead of entire starvation mode (Russell, 2017).

Notably, different studies have examined caloric intake in AN weight gain and have made estimations on the caloric intake amount required in gaining weight in kg. Most importantly, caloric requirements differences have been shown between AN groups subtype, with R-AN victims requiring more calories compared to BP-AN victims in gaining similar weight amounts.

Considering different experiments, AN tends to need escalating intake in calories in maintaining a 1 to 1.5 kg/week gain in weight during the period of hospitalization. In fact, healthy women who are not victims of an eating disorder need approximately 30 kcal/kg/day in maintaining their weight which ranges between 20 to 40 daily kcal/ kg. If re-feeding for AN people began on this amount, they ultimately would fail in gaining weight. Instead, the intake in calorie would be required to be increased over time in steps to between 60 to 100 daily kcal/ kg in sustaining their weight gain (Minuchin, 2018).

Role of energy metabolism and exercise in weight gain resistance

Of importance, obese people on losing weight they become hypo-metabolic, meaning that they lose their intake in calories but face difficulties in losing weight or to maintain the weight that they have lost for a while. On top of this, in case of raising their intake in food, they easily gain weight. AN people have a totally different problem meaning that they turn to be hypermetabolic, easily losing weight, and are required to eat high food amounts in gaining weight. Thus, intake in calorie has low efficiency based on being converted to AN patient‘s tissue (Palazzoli, 2015). Furthermore, it has been proven that patients who had a previous history of obesity rapidly gain weight compared to non-obese patients. This suggests that metabolic rate differences play a major role in the weight gain effort outcome.

Markedly, excessive exercise is an exhibited behavior by many patients of AN. On top of severe emaciation, different patients continuously stand or experience restless motions or others spend a substantial day portion jogging or pacing. This kind of exercise may contribute to the high requirements in calories in weight gain. Caloric expenditure literature in emaciated patients’ furring exercise is scarce. According to different scholars, they stated that the exercise amounts engaged by AN individual’s results in around threefold calories range needed in gaining one kilogram. This means that individuals who take little exercise require only 4,000 calories in excess in gaining one kilogram of weight, whereby those taking extreme exercise require more than 12,000 more calories in gaining similar weight (Russell, 2017).

Medical weight restoration consequences

According to different researchers, emaciation is related to considerable medical complications. Or instance, many patients of AN are victims of a compromised status of cardiovascular and fluid balance shifts, with some patients being over-hydrated while others being dehydrated, others have reduced blood albumin levels and anemia. In case enteral or parenteral re-feeding is vital due to extreme resistance, nutrients administration should be slowly practiced, beginning with not more than 500 daily kcal given as complete liquid form diet for many days, then followed by a gradual caloric load increase through a step-wise manner (Brumberg, 2018).

An important side effect in weight gain restoration is the re-feeding syndrome as a result of rapid re-feeding during the starvation state, mainly chronic condition. Notably, the adverse rapid acute re-feeding effects have been an issue since rehabilitation concentration experience with camp survivors. The syndrome is characterized biochemically with hypomagnesemia, glucose intolerance, hypophosphatemia, hypokalemia, thiamine deficiency, and fluid overload. Clinical consequences may include hypotension, coma, seizures, and weakness of the skeletal muscle, heart failure, cardiac arrhythmias, respiratory failure, and rhabdomyolysis (Minuchin, 2018).

Weight gain rate

Notably, AN patients need about 5,000 to 10,000 calories in excess in gaining a kilogram of weight. This reason behind this wide range in calories gain is unclear. Nonetheless, many factors have been suggested in trying to define the variability such as individual energy efficiency variations, physical activity, synthesized tissue composition, treatment phase, age, thermoregulatory response, and fluid shifts (Russell, 2017).

Weight Maintenance

After getting their weight of a healthy body, both BP-AN and R-AN have high energy inefficient and need a high intake of calories in maintaining the weight that is restored. In fact, if healthy women require 30 daily kcal/kg for maintaining their weight, the weight maintenance amount is between 50 and 60 daily kcal per kg for a patient of AN. The requirement for high calorie can be associated to slow neuroendocrine processes normalization. Without this food substantial amount, there is always a high loss in weight due to the high relapse rate is shown in about 50 percent of AN victims. Upon hospital discharge, eating attitudes show a reliable outcome predictor. It has been documented by different scholars that patients with AN sometimes regress to a body that is underweight after a follow-up of one year after hospitalization. Physiological and psychological, neuroendocrine, and metabolic factors result in the long-term recovery of a serious syndrome. Moreover, increased needs in calories cannot be examined by mal-absorption (Palazzoli, 2015). However, scientific data literature indicates that needs in calorie sometimes normalize. Notably, during 3 to 7 months, both BP-AN and R-AN indicate metabolism normalization that is the same as the caloric amount required by women who are healthy and not victims of an eating disorder. In obtaining a long-term weight recovery maintenance best chance, AN patients must persist in an intake treatment plan of increased calories (Garner, Olmstead, and Polivy, 2013).

Nutrient Intake

From the perspective of nutrition, the replenishing chances of micronutrient and macronutrient requirements are enhanced by increasing the food variety that was prescribed to the patients. In essence, this is difficult for victims as eating food variety resistance is the main symptomatology element. A crucial clinical issue is no particular macronutrient requirements distributions recommendations in eating disorder people has been documented. However, the daily macronutrient needed in maintaining weight as was stated by the Institute of Medicine is between 110 to 140 carbohydrates grams, 15 to 20 essential fatty acids grams as well as one protein gram per kilogram of the weight of the body. Remarkably, the Recommended Daily Allowances (RDA’s) for minerals and vitamins vary based on gender and age, although they can be compensated for the multi-mineral or multivitamin intake (Suilivian, 2015). Emphasizing the requirements of nutrients, attained in food intake, as opposed to an intake of calories, may be of help in lessening the resistance and anxiety on re-feeding experienced by patients.


In the clinical experience, using, intuition, insight, and reason are not enough in convincing a person with AN to eat. This is because patients are highly subjective and have little backing information on the reasons they should eat in scientific research. Thus, in restoring both weight and nutrient status gradually and slowly rise as it is tolerated. For a fact, there must be a continued emphasis on the intake of nutrients as it is different in taking calorie, which should be accompanied by psychotherapy encouragements in raising both the diversity and amount in food selections with the ultimate goal of nutrition and weight restoration. Considering that diet diversity is weight maintenance predictive in patients of AN, most emphasis should then be put on nutrient status and intake in providing a less approach of anxiogenic to achieve increased diversity in the diet that should ultimately result in consistent food levels intake capable of maintaining a normal weight range.


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Sullivan, P. F. (2015). Mortality in anorexia nervosa. American Journal of Psychiatry152(7), 1073-1074.