Recovery Without Medical Supervision Can Be Fatal in Malnourished Anorexic Patients Presenting at Low Weights
In recovery from anorexia nervosa, which manifests as an individual restricting his or her caloric intake to result in a significantly low weight, an idea exists among non-scientific persons that the most prudent course of action is an immediate and drastic increase in caloric intake in order to remedy severe weight restoration. Unfortunately, patients who are severely malnourished and present at severely low weights are at an increased risk for refeeding syndrome, which if not addressed immediately can result in acute cardiac arrest and death.
Refeeding syndrome occurs when electrolyte levels are suddenly and drastically altered with the introduction of proper nutrition [1,4]. In a body that has been deprived of carbohydrates for an extended period of time, metabolic and hormonal functions are significantly altered, as the body becomes reliant on adipose tissue, or body fat, in addition to muscular protein stores that exist within the skeletal and cardiac muscle [2,3]. In other words, the body adapts to the restriction of dietary carbohydrates by decreasing the production of insulin, which allows glucose from metabolized carbohydrates to enter the cells of the body and stimulates glycogen and protein synthesis .
However, when carbohydrates are reintroduced into the body, as occurs during the refeeding process for anorexia patients, insulin levels increase in order to metabolize the carbohydrates, which allows glucose to be absorbed into the cells for glycogen and protein synthesis . Unfortunately, the synthesis of glycogen and protein requires important minerals, namely phosphate, magnesium, and potassium, which may are often deficient in malnourished patients [2,4]. Refeeding syndrome occurs when already diminished phosphate, magnesium, and potassium are absorbed from the bloodstream into cells of the body that are attempting to metabolize carbohydrates, leaving blood levels of those important minerals to be dangerously low [1,2,4].
Role of Nutrition in Refeeding Syndrome:
When such an intense electro-chemical gradient exists between extra-cellular, such as the bloodstream, and intra-cellular environments, these minerals enter into the cell quite rapidly, which obviously causes a dramatic shift in electrolyte levels throughout the body. These shifts can occur suddenly and without warning within any malnourished patient, leading to the malfunction of vital organs, such as the heart, which is reliant on proper electrolyte balance to pulse rhythmically; the nerves present within the brain and throughout the nervous system, which function by using electro-chemical gradients to send electric signals; and the skeletal muscles, which also rely on alternating electro-chemical gradients to contract and extend .
As a result of multiple organs being affected by the rapid electrolyte imbalances occurring as a result of refeeding syndrome, symptoms can range from mild nausea, vomiting, and fatigue to severe cardiac arrhythmias, respiratory and heart failure, coma, and even death [1,4,5]. As is evident, the body is immensely reliant on the maintenance of electrolytes and other vital minerals, which are responsible for the regular functioning of vital organs. The effects of altered levels of phosphate, potassium, magnesium, sodium, and vitamins is represented in Table 1: the clinical manifestation of electrolyte abnormalities associated with refeeding syndrome .
While refeeding syndrome is a rare occurrence, some patients carry a higher risk than others. Patients with a high risk of developing refeeding syndrome are defined as having a BMI of less than 16 kg/m^2, experiencing weight loss greater than 15% of total body weight within three to six months, and having negligible food intake for more than ten days [1,2]. Patients with a moderate risk of developing refeeding syndrome are defined as having a BMI of less than 18 kg/m^2, experiencing weight loss greater than 10% of total body weight in three to six months, having negligible food intake for more than five days, and have a history of alcohol or diuretic abuse or have undergone chemotherapy [1,2].
The high mortality rate of refeeding syndrome very clearly illustrates the need for medical supervision during the refeeding process in recovery from anorexia nervosa. The symptoms of refeeding syndrome can occur suddenly and without warning, which can be a dangerous and tragic situation if the patient is not within minutes of medical care. Attempting refeeding without medical supervision, even in patients suffering from bulimia or EDNOS, is risky and dangerous. Refeeding syndrome is very serious and can kill swiftly and without warning.
 Khan et al. 2011. Refeeding syndrome: a literature review. Gastroenterology Research and Practice 2011 (2011): 6.
 Mehanna et al. 2008. Refeeding syndrome: what it is, and how to prevent and treat it. British Medical Journal 336(7659): 1495 - 1498.
 Hearing S. D. 2004. Refeeding syndrome. British Medical Journal 328: 908.
 Boateng et al. 2009. Refeeding syndrome: treatment conditions based on collective analysis of literature case reports. Nutrition 26(2): 156 - 157.
 Stanga et al. 2008. Nutrition in clinical process - the refeeding syndrome: illustrative cases and guidelines for prevention and treatment. European Journal of Clinical Nutrition 62: 687 - 694.