Rapid introduction of calories in a patient with malnutrition (pre-existing catabolic state)
Sudden influx of excess carbohydrates, results in higher insulin, and increases movement of phosphate and potassium intra-cellularly (also increased thiamine utilisation)
Leads to low potassium, magnesium, phosphate and a thiamine deficiency (phosphate is the first to drop)
Usually occurs within the first 72 hours of refeeding
Hypophosphataemia is the hallmark of refeeding syndrome, and generally manifests during the first week of re-feeding
