Eating Disorder Behaviours

Knowledge Translation Commentary

Here are many ways that patients compensate for the food they consume in an effort to lose weight or prevent weight gain.

Purging behaviours are very physically damaging and can cause life-threatening medical complications.

Purging behaviours include:

• Self-induced vomiting
• Laxatives
• Diuretics
• Diet pills
• Chewing and spitting out food or rumination
• Excessive exercise and hyperactivity
• Ipecac

Self-induced vomiting:

• Leads to dangerous fluid and electrolyte abnormalities, namely dehydration, hypochloremia, hypokalemia, and metabolic alkalosis.
• Signs of self-induced vomiting include Russell's sign (calluses on the knuckles or back of the hand due to repeated self-induced vomiting over long periods of time), a face that appears swollen due to enlargement of the parotid and submandibular glands, dental complications, e.g erosion of enamel, dental caries, erythema of the soft tissues of the mouth (palate, pharynx, and gingiva).

Laxatives: Act primarily on the large intestine after the absorption of nutrients, which occurs primarily in the small intestine, and therefore are an ineffective method of avoiding calorie absorption. They interfere with fluid absorption and produce a temporary fluid loss caused by watery diarrhea that gives the patient a sense of weight loss. Reflex fluid retention and weight gain leads to further usage, and over time tolerance develops and patients increase their dose. Individuals can ingest 60 or more tablets daily.

Diuretics: Can lead to significant hypokalemia. Also leads to reflex fluid retention which causes weight gain and sustains diuretic use.

Diet pills: Usually includes over the counter drugs with amphetamine and caffeine. Patients can also abuse thyroid medications. They often titrate their dose to dangerously high levels causing cardiac arrhythmias. Other side effects include rebound fatigue, hyperphagia, insomnia, mood changes, irritability, and in rare case, psychosis.

Chewing and spitting out food or rumination: Rumination refers to the conscious regurgitation of gastric contents that are then chewed and swallowed again. This symptom can result in rapid erosion of the teeth, aspiration, and Barrett's esophagus (a precancerous lesion of the lower esophagus). This is often missed and patients rarely volunteer this symptom.

Excessive exercise and hyperactivity: Patients with AN not only engage in excessive and intense aerobic activity, but also spend much of their day either standing, fidgeting, or walking. Often, they are not aware of how hyperactive they are.

Ipecac: Is an over the counter drug that contais the alkaloid emetine. Patients use this as a way of promoting vomiting. This drug is particularly dangerous as it causes gastrointestinal, cardiovascular, and neuromuscular toxicity.