A University of California, San Francisco (UCSF) study challenges the current conservative approach to feeding adolescents who have anorexia nervosa during hospitalization for malnutrition, suggesting a higher calorie diet may be called for.
Health plans often limit the duration of an individual’s hospitalization, and researchers are also concerned with the psychological and emotional impact that may result from rapid hospital discharge.
Anorexia is an eating disorder characterized by a refusal to maintain a healthy body weight, and an obsessive fear of gaining weight. This disorder may become life-threatening requiring hospitalization. Medical care is typically directed at refeeding to gain significant weight during their first week in the hospital.
According to the researchers, current guidelines recommend starting with about 1,200 calories per day and advancing slowly by 200 calories every other day.
This “start low and go slow” approach is intended to avoid “re-feeding syndrome” — a potentially fatal condition resulting from rapid electrolyte shifts, a well-known risk when starting nutrition therapy in a starving patient.
The new research is the first to test these recommendations, which have been in place since 2000.
“Our findings show that the current recommendations are just not effective,” said Andrea Garber, Ph.D., R.D., associate professor of pediatrics who led the research with colleagues in the UCSF Adolescent Eating Disorders Program.
Study participants were hospitalized due to signs of malnutrition, including low body temperature, blood pressure, heart rate and body mass index. The vast majority of the 35 primarily white, female adolescent patients received low-calorie diets based on the current recommendations.
Patients were fed six small meals per day, and when they refused food, they were given high calorie liquid supplements as a replacement. The patients’ vital signs were monitored closely, with their heart rates measured continuously and electrolytes checked twice a day.
While the low calorie diets did prevent refeeding syndrome for those patients, about 83 percent of them also experienced significant initial weight loss and no overall weight gain until their eighth day in the hospital. This finding represents “a missed opportunity,” according to Garber.
“Studies show that weight gain during hospitalization is crucial for patients’ long-term recovery,” she said. “We have to make the most out of their short time in the hospital.”
In the new study a range of diets were evaluated from 800 to 2,200 calories. This caloric variation allowed the researchers to examine the effect of increasing calories. According to Garber, two important findings emerged:
- The calorie level of the starting diet predicted the amount of weight that would be lost in the hospital. In other words, those on lower calorie diets lost significantly more weight.
- Higher calorie diets led to less time in the hospital. In fact, Garber said, “we showed that for every 100 calories higher, the hospital stay was almost one day shorter.”
While the study finds that current recommendations are too cautious, it raises other questions, according to the research team. For example, while a shorter hospital stay may reduce insurance costs, patients may not be ready to go home yet.
“Shorter is not necessarily better,” said Garber. “We have to consider the potential implications down the line, both psychological and emotional.”
Another unanswered question relates to refeeding syndrome, which remains “a very real fear,” according to Barbara Moscicki, M.D., a professor of pediatrics and senior author on the paper.
Moscicki says that the team is proceeding cautiously since more aggressive approaches to feeding and supplementation have not yet been well studied.
Nevertheless, the researchers say that the study results are a promising start because no adverse events were seen in the study subjects on the higher calorie diets. “If we can improve weight gain with higher calories,” Garber said, “then we’re on the right path.”
Research findings will be published in the January issue of the Journal of Adolescent Health with an accompanying editorial.