Refeeding syndrome was first described in Japanese prisoners of war from World War II who had been starved while imprisoned. It is a complex of biological symptoms that can occur when food is reintroduced to people who are starved or severely malnourished.
People who have not eaten for 5 or more days are at an increased risk for refeeding syndrome and may experience a constellation of metabolic derangements, electrolyte disturbances,and fluid imbalances.
Refeeding is not the same as renourishment
Refeeding syndrome may be confused with renourishment because they sound as if they might be similar processes. However, renoursihment is actually the process of reintroducing food to people who are malnourished or starved such as those who suffer from Anorexia Nervosa. Renourishment is conducted slowly and monitored diligently in an attempt to prevent consequences of refeeding syndrome.
When the body is starved it implements various physiological mechanisms to conserve muscle tissue and slow the metabolism. To achieve this various hormones are increased or decreased, the body begins to burn ketones rather than glucose, and electrolyte stores are used. For instance, in a starved person insulin secretion decreases while glucagon increases, they may develop fruity-smelling breath as they experience ketosis, and they deplete body stores of phosphate, magnesium, and calcium.
Refeeding increases insulin, decreases glucagon
In refeeding syndrome, food is introduced after prolonged starvation and this leads to an increase in insulin and decrease in glucagon. The body increases metabolism and switches from using ketones as the primary energy source back to glucose. But the switch from starvation to normal functioning may not go smoothly if it occurs too quickly.
Most importantly, phosphates are used up rapidly as well as magnesium and potassium. These ions are very important to maintain proper body functions. When they are deranged as in refeeding syndrome, it can result in cardiac arrhythmias, confusion, convulsions, coma, or even death.
To avoid refeeding sydrome, severely malnourished individuals are usually given milk as a main energy source because it is generally well tolerated and naturally has high phosphate levels. Only 50% to 70% of total necessary calories are generally introduced at first to give the body time to adjust. In addition, various supplements, vitamins, and minerals may also be given to restore electrolyte stores. Some medications may also be used to support the gastrointestinal system as it once again digests and absorbs food.