187: Weight For It… New Guidelines on Faltering Weight!

July 29, 2026 | By Sydney Engel

Audio

Failure to thrive is out, faltering weight is in! Join us as pediatric gastroenterologist and guideline author Dr. Praveen Goday weighs in on the new AAP guideline for faltering weight. Learn how to use z-scores to identify children at risk for malnutrition, when nutritional intervention should precede diagnostic testing, and practical strategies to support catch-up growth across the pediatric age spectrum. Tune in to learn how to tip the scales toward healthy growth while avoiding unnecessary testing.

Faltering Weight Pearls

1. Think of faltering weight as a child being at risk for malnutrition—aim for early recognition and intervention before height and overall growth are affected.
2. Use weight-for-length (or BMI) and z-scores rather than percentile crossing alone; a decline of ≥1 z-score is more meaningful than simply dropping percentiles.
3. Most children with faltering weight do not need extensive testing upfront—insufficient caloric intake is far more common than an underlying medical disorder.
4. A detailed feeding history is often more valuable than laboratory testing; ask about breastfeeding effectiveness, formula preparation, grazing, juice intake, and meal structure.
5. For formula-fed infants, increasing formula concentration to 24 kcal/oz is a simple and effective first-line intervention that often provides the extra calories needed for catch-up growth.
6. Symptoms should drive the workup: vomiting, diarrhea, developmental delay, cardiorespiratory symptoms, or signs of nutritional deficiency warrant targeted evaluation beyond nutrition alone.
7. Children who fail to respond to adequate caloric intervention deserve a broader evaluation and may benefit from subspecialty support, including GI, feeding therapy, and/or developmental services.

Faltering Weight Notes 

Key Updates to Definitions

“Failure to Thrive” Has Been Replaced by “Faltering Weight”: The new terminology avoids stigmatizing language and emphasizes early recognition of children at risk for malnutrition before more significant growth impairment occurs.

Think Beyond Percentiles—Use Z-Scores: A drop in percentiles can be misleading depending on where a child starts on the growth curve. Z-scores provide a standardized way to assess growth changes across the spectrum. Criteria used to define faltering weight include:

• Weight-for-length or BMI z-score below -1.65 (approximately the 5th percentile) 
• Decline of ≥1 z-score over time 
• In children younger than 2 years, weight gain velocity less than −2 z-score for age (2.3rd percentile)

Evaluation

History

Every history should include a detailed dietary intake, which may include:

• Breastfeeding frequency, duration and patterns
• Formula quantity and preparation
• Juice and sugar-sweetened beverage intake
• School meals
• Feeding behaviors such as grazing and family mealtime routines

History should also include:

• Family history (e.g., celiac disease, inflammatory bowel disease, genetic conditions)
• Developmental milestones
• Access to food resources (WIC, SNAP) and other social determinants of health

Physical Exam

• Signs of chronic disease (e.g., hepatosplenomegaly, thyroid enlargement, genitourinary abnormalities, hypo/hypertension)
• Neurologic abnormalities (e.g, abnormal deep tendon reflexes, hypotonia)
• Dysmorphic features
• Signs of nutrition deficiency (e.g., scaling skin, spoon-shaped nails, edema, bony deformities)
• Evidence of cardiorespiratory disease (e.g., murmur, tachycardia, tachypnea, clubbing)

When to Consider Testing

Testing becomes more important when:

• Growth failure is severe, particularly if approaching a weight-for-length or BMI z-score <-3, which would meet criteria for malnutrition
• Nutritional interventions are unsuccessful
• Symptoms suggest a specific diagnosis
• History and exam do not explain poor growth 

Signs and symptoms warranting testing include:

• Persistent vomiting
• Significant diarrhea
• Developmental delay
• Cardiorespiratory symptoms
• Severe constipation
• Signs of nutritional deficiency

Potential testing may include:

• Celiac screening
• Thyroid studies
• Endoscopy
• Metabolic evaluation
• Additional subspecialty-directed workup

Management

Nutritional Intervention

Breastfed Infants

• Optimize feeding frequency and technique
• Supplement with formula when needed. Dr. Goday will work with the family to determine what is easiest, but often will recommend 2-3 supplemental feeds of formula or expressed breast milk fortified to 27 kcal/oz each day
• Shared decision-making is essential – figure out what will work best for the family

Formula-Fed Infants

• Verify proper formula mixing (all US-based formulas are 1 scoop per 2 ounces of water)
• Increase caloric density (typically to 24 kcal/oz) – there are many good online resources to teach families how to prepare this using their regular formula, which is preferred to switching to higher kcal/oz formulas designed for preterm infants 
• Consider step-down towards standard caloric density once the baby is maintaining target weight gain (Dr. Praveen will typically follow up every 1-2 months)

Toddlers and Older Children

• Establish structured meals and snacks; avoid grazing 
• Limit juice and sugar-sweetened beverages
• Add calorie-dense foods strategically (e.g., oils, butter, cream)
• Consider high-calorie nutritional supplements (30 kcal/oz beverages – often given at bedtime to avoid “spoiling the appetite” for other meals) 

Appetite Stimulants

Cyproheptadine may be useful in select children, although effects often diminish over time. Dr. Goday will always start with adding calories first, but in children who struggle to gain weight due to low appetite this is a reasonable next step. He tends to give it as a single bedtime dose rather than divided into multiple doses to increase adherence. 

Referral/Hospitalization 

Consider referral for:

• Feeding dysfunction (OT/feeding therapy)
• Persistent growth concerns despite intervention
• Suspected gastrointestinal disease
• Developmental concerns requiring specialist evaluation

Hospitalization may be appropriate when:

• Malnutrition is severe (e.g., z-score < -3)
• The history does not match the degree of growth failure
• Outpatient follow-up is difficult
• Urgent diagnostic evaluation is needed

Resources

• American Academy of Pediatrics Clinical Practice Guideline: Clinical Practice Guideline for Diagnosis and Management of Faltering Weight (2026)
• American Society for Parenteral and Enteral Nutrition (ASPEN)
• North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN)

Goal

After listening to this episode, listeners will be able to recognize faltering weight early, perform a focused evaluation, and implement practical nutritional interventions to prevent progression to pediatric malnutrition.

Learning Objectives

After listening to this episode listeners will…  

1. Define faltering weight using the updated AAP diagnostic criteria, including the role of weight-for-length, BMI, and z-scores.
2. Identify key historical, physical exam, and growth chart findings that help distinguish inadequate caloric intake from underlying medical causes of faltering weight.
3. Describe an evidence-informed approach to evaluating children with faltering weight, including when nutritional intervention should precede diagnostic testing.
4. Implement practical age-specific strategies to increase caloric intake in breastfed infants, formula-fed infants, and older children with faltering weight.
5. Recognize indications for targeted laboratory evaluation, subspecialty referral, and hospitalization in children with faltering weight.

Disclosures

Dr. Goday has financial relationships with Kate Farms and Nutricia for research support and Abbott for consulting fees. All efforts have been made to present balanced information about treatment options.

Citation

Engel S, Goday P, Lidsky H, Chiu C, Masur S. “#187: Weight for it…New Guidelines on Faltering Weight”. The Cribsiders Podcast. https:/www.thecribsiders.com/ July 29, 2026