Synopsis
Identify a clinically important change in growth trajectory, verify measurement and intake, observe feeding, distinguish nutritional, medical and psychosocial causes, intervene proportionately and protect the child without stigmatising or blaming the family.
- Use serial accurate measurements, not visual impression. Plot weight and length or height on UK-WHO charts, correct for prematurity when appropriate and review the trajectory from birth.
- NICE thresholds for concern are a fall across 1 centile space when birth weight was below the 9th centile, 2 spaces when between the 9th and 91st, or 3 spaces when above the 91st; current weight below the 2nd centile also warrants concern.
- Weight loss above 10% of birth weight triggers clinical assessment, feeding history and direct observation, but does not by itself diagnose disease or mandate formula.
- First-line investigation is a detailed clinical, developmental and social assessment plus an observed feed or meal by a competent practitioner.
- Measure length or height and, over age 2, calculate BMI centile. Weight faltering with preserved length often reflects recent energy deficit; impaired length suggests longer duration or systemic disease.
- Ask what is actually offered and consumed: milk preparation, feed frequency, texture, meal structure, supplements, vomiting, stool, feeding interaction and food access.
- NICE advises considering urinary tract infection and coeliac disease when clinically indicated. Broad routine blood panels have a low yield in a well child without other clinical features.
- Management is stepwise: correct feeding mechanics and routine, increase energy and nutrient density using ordinary foods, involve a paediatric dietitian, then consider a time-limited oral supplement only with goals and review.
- Tube feeding is not a shortcut for diagnostic uncertainty. Use specialist multidisciplinary assessment when intake remains insufficient or swallowing is unsafe, with an exit and oral-experience plan.
- Discuss growth in neutral language. Food insecurity, caregiver illness and inaccessible advice are treatable contributors, not evidence of indifference.
Key red flags
Lethargy, reduced urine, prolonged capillary refill, hypothermia, hypoglycaemia or severe wasting requires same-day paediatric assessment.
Weight loss, rather than slow gain, after the neonatal period is more concerning and needs prompt explanation.
Bilious or projectile vomiting, chronic diarrhoea, blood in stool, dysphagia, cough with feeds or recurrent infection indicates organic disease.
Developmental regression, abnormal tone, cardiac or respiratory signs, organomegaly or dysmorphism broadens assessment beyond feeding.
Disproportionately poor linear growth, delayed puberty or Cushingoid features suggests endocrine or chronic systemic disease.
Inconsistent histories, missed care, deliberate restriction, unsafe formula dilution or failure to implement feasible support raises safeguarding concern.
Investigation priorities
Confirm the growth pattern and identify modifiable intake or skill problems.
Management branches
A measurement or trajectory raises concern.
- Repeat accurate weight and length or height and plot all prior reliable measures.
- Apply NICE centile-space thresholds and assess current clinical urgency.
- Complete developmental, medical and social assessment and observe feeding.
The child is stable and intake or interaction can improve.
- Agree regular meals and snacks, responsive boundaries and correction of breast, bottle or texture technique.
- Increase energy and nutrient density with dietitian-informed affordable foods while protecting appetite.
- Set measurable goals and a proportionate review interval.