The American Academy of Pediatrics, in partnership with the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN), has published its first clinical guidance on diagnosis and management of "faltering weight," formerly described as "failure to thrive." The condition affects 5% to 10% of young pediatric patients who are not growing as expected.
The "Clinical Practice Guideline for Diagnosis and Management of Faltering Weight" and two accompanying technical reports are published in the April 2026
Pediatrics. The reports provide a clear definition of faltering weight with specific diagnostic criteria. It also lays out a consistent approach to the evaluation and management of children suspected of having faltering weight.
"The guideline takes a whole-child approach to evaluation and treatment and recognizes that safe, stable, nurturing relationships are necessary components for normal growth and development," said
Hans B. Kersten, M.D., FAAP, lead author of the guideline.
"The goals are to help doctors make accurate diagnoses, avoid unnecessary tests, and use health care resources wisely," Dr. Kersten said.
Faltering Weight is a common reason for pediatric clinic visits and hospital admissions. The AAP no longer uses the term "failure to thrive" because it has no precise definition, is stigmatizing and has unclear standards of care.
Diagnosis & treatment for faltering weight
For the first time, a mathematical calculation called the z-score (or standard score) is used to more accurately measure the infant's weight.
According to the guideline, a child may be diagnosed with faltering weight if they meet any of the criteria:
Weight-for-length, or BMI-for-age <-1.65 z score (5th percentile—or around the bottom 5%)
In children younger than age 2, weight gain velocity <-2 z score for age (2.3rd percentile)—which is much slower than expected
Decline in weight, weight-for-length, or BMI ≥1 z score
Testing such as imaging studies and laboratory tests are recommended only if there are signs of a specific problem or if poor weight gain continues. Endoscopy is recommended only for those children who have persistent faltering weight after appropriate therapies have been tried or in other cases in which diagnosis cannot be confirmed without looking inside the body.
Treatment recommendations include increased calories through food or energy-rich meals, use of oral nutrition supplements, and therapy for feeding disorders.
How the guideline was developed
This clinical practice guideline is a partnership between the AAP and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. Policies and guidelines created by AAP are written by medical experts, reflect the latest evidence in the field, and go through several rounds of peer review before being approved by the AAP Board of Directors and published in Pediatrics.
The AAP also contracted with the Evidence Foundation to conduct a systematic review of evidence and chose a panel of experts to facilitate the guideline's development. The panel included general and subspeciality pediatricians, an informatician, an epidemiologist, a social worker, a dietitian, a psychologist and a patient representative.
The clinical practice guideline includes two technical reports that examine evidence supporting the guideline.
- "The Benefits and Harms of Endoscopy and Other Diagnostic Tests to Detect Underlying Conditions in Children With Faltering Weight: Results of Two Technical Reviews" describes systematic reviews to identify the benefits and harms of diagnostic tests, including endoscopy, in children younger than 5 years who live in high-income countries.
- "The Impact of Socioeconomic Status and Different Treatment Modalities on Children With Faltering Weight: Results of Four Technical Reviews" suggests that socioeconomic status is not a reliable predictor of failure to thrive in children younger than 5 years who live in high-income countries.
More information