Higher calorie treatment for people hospitalized with anorexia

The study is testing refeeding approaches in young people hospitalized for anorexia. SDI Productions/ E+ via Getty Images

People with anorexia nervosa may see themselves as overweight, but they are often dangerously underweight. Long periods of malnutrition and even starvation can damage the bones, heart, brain, and other organs. Anorexia is the deadliest of the eating disorders: about 5% of people with the condition will eventually die from its complications.

When people are hospitalized for anorexia, they go through a period of supervised refeeding to increase their weight and stabilize their vital signs and organ function. Traditionally, this has been done by starting with a lower calorie diet and proceeding cautiously. The approach involves slow weight gain and an often lengthy hospital stay.

Many doctors believed that giving people with severe malnutrition too many calories at once could be dangerous. Prisoners during wartime have experienced a rare phenomenon called refeeding syndrome. In this syndrome, starving people fed too quickly develop an imbalance in electrolytes, such as potassium and magnesium. This can lead to heart attack and death.

Some hospitals have begun to use higher calorie refeeding programs for anorexia treatment, but studies have not yet determined the safety of this approach. In a new clinical trial, researchers led by Dr. Andrea Garber from the University of California, San Francisco directly compared the two approaches. They recruited 111 people between the ages of 12 and 24 who were hospitalized for anorexia. People with a BMI of 60% or lower than normal weren’t recruited, as they are very fragile and require more care.

The team randomly assigned participants to one of two refeeding programs. The lower-calorie group began at 1,400 calories a day. This increased slowly, every other day, to reach weight-gain goals. Higher-calorie refeeding started at 2,000 calories a day and increased every day as needed.

The researchers compared how long it took for participants to reach medical stability. This benchmark included improvements in heart rate, blood pressure, and body temperature, and reaching at least 75% of the average body max index (BMI) for their age and sex.

The study was funded in part by NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Results were published on October 19, 2020, in JAMA Pediatrics.

An equal proportion of people in both groups reached medical stability during hospitalization. However, people in the higher-calorie group stabilized an average of 3 days earlier than those receiving fewer calories.

People in the higher-calorie group also had their heart rates normalize faster and gained more weight overall. Earlier stability led to shorter hospital stays; people in the higher-calorie group were able to leave the hospital an average of 4 days earlier than those given the lower-calorie regimen.

Higher-calorie refeeding appeared to be safe. Electrolyte problems did not differ between the groups, and no cases of refeeding syndrome occurred in either group.

The research team will continue to follow all participants for a year after treatment.

“We are eager to find out if the benefits in hospital are sustained over time,” Garber says. “We want to avoid a situation in which shorter stays create a revolving door of more frequent readmissions, undoing early good outcomes and hospital cost savings.”

—by Sharon Reynolds