# Refeeding Syndrome in Children

> Refeeding syndrome for NEET-PG Paediatrics: hypophosphataemia after feeding starved children, risk criteria, thiamine, slow calorie start and monitoring.

- Canonical URL: https://prepelephant.com/topics/neet-pg/paediatrics/refeeding-syndrome
- Exam / course: NEET-PG · Subject: Paediatrics
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-02
- Last updated: 2026-10-02
- How to cite: "Refeeding Syndrome in Children", PrepElephant, https://prepelephant.com/topics/neet-pg/paediatrics/refeeding-syndrome

## Direct answer

Hypophosphataemia within 72 hours of starting feeds in a severely malnourished child is refeeding syndrome: the switch from fat to carbohydrate metabolism drives insulin release, shifting phosphate, potassium and magnesium intracellularly — the quartet of hypophosphataemia (the hallmark, below about 2 mg/dL), hypokalaemia, hypomagnesaemia and fluid retention, with cardiac failure, arrhythmia, seizures, respiratory weakness and sudden death. The at-risk child in India is usually the severely wasted child, but anorexia nervosa, prolonged fasting, post-operative states and chronic illness all qualify. Prevention is the therapy: thiamine and B-complex before feeding, about 10-20 kcal/kg/day initially in high-risk children (advancing over four to seven days), electrolyte correction, fluid and sodium restriction, and daily potassium, phosphate and magnesium for the first week — the WHO severe-malnutrition protocol's cautious F-75 starter formula embodies exactly this logic.

## What you must remember

- **Mechanism in one sentence:** refeeding switches the starved body from ketone-based fat to glucose metabolism; insulin surges, driving phosphate, potassium and magnesium into cells while extracellular stores are depleted — the serum falls as the body consumes.
- **Biochemical quartet with timings:** phosphate falls within 12-72 hours (hallmark, below 2 mg/dL), potassium and magnesium follow, thiamine decompensates acutely, and fluid retention follows sodium retention.
- **Clinical consequences map:** cardiac failure and arrhythmia (QT prolongation, sudden death) on an atrophic myocardium, respiratory muscle weakness, haemolysis with infection risk, and Wernicke encephalopathy.
- **Risk criteria to recite:** severe acute malnutrition (weight-for-height below -3 z or MUAC below 115 mm), negligible intake for five or more days, rapid weight loss, anorexia nervosa, and pre-existing electrolyte depletion — the NICE-style screening logic.
- **Prevention protocol:** thiamine plus B-complex before the first feed; start at 10-20 kcal/kg/day in high-risk children, advancing over four to seven days; correct potassium, phosphate and magnesium before or with feeding; restrict fluid and sodium; avoid iron in stabilisation.
- **Monitoring discipline:** electrolytes and glucose daily for the first five to seven days, plus fluid balance, weight (gain beyond about 10 g/kg/day signals overhydration) and cardiac review.
- **The WHO translation:** F-75 starter formula (75 kcal per 100 mL), deliberately low in protein, sodium and iron, steps up to F-100 or ready-to-use therapeutic food only after appetite returns — refeeding management built into the programme, an Indian-practice anchor.
- **Treatment of established syndrome:** stop or halve feeding, correct phosphate (1-2 mmol/kg over 4-6 hours), potassium and magnesium, thiamine urgently, fluid restriction, cardiac monitoring.

## A preventable death walked through — and then prevented

Take a 14-month-old, weight-for-height z-score below -4, oedematous, from a drought district with five days of almost no intake. The wrong pathway is "he is starving, feed him": high-energy feeds and a dextrose bolus, apparent stabilisation, then day-two pulmonary oedema, phosphate 1.1, potassium 2.8, arrhythmia — the atrophic, thiamine-starved myocardium failing under the load. The right pathway from hour zero: prevent hypoglycaemia and hypothermia, give thiamine and B-complex, start F-75 (roughly 80-100 kcal/kg/day), hold iron, use sodium-poor fluids, and give antibiotics — severe malnutrition is infection until disproven. Chart discipline: electrolytes baseline and daily; when phosphate drifts to 2.1 on day two, feeds continue while oral phosphate corrects — watched, not celebrated. Around day four to seven appetite returns — the programme's own signal — and catch-up feeding (F-100 or ready-to-use therapeutic food) begins, guided by the child demanding feeds rather than the calendar. The twin exam messages: the child dies of the treatment, not the starvation, and every severe-malnutrition protocol is at heart a refeeding-syndrome prevention protocol.

## Where students slip

Equating refeeding syndrome with "too many calories" alone misses the electrolyte shift as the killer — hypophosphataemia is the answer the exam wants, and its 72-hour window is stated verbatim in stems. Second, iron given early in severe acute malnutrition; it is withheld in stabilisation (free-iron infection risk) — a WHO-specific detail exams love. Third, thiamine remembered as "alcoholics" knowledge and omitted in paediatrics, yet it must precede the first feed. Fourth, overhydration misread as "the malnutrition worsening" — rapid weight gain is fluid, and the answer is restriction, not more protein.

## Frequently asked questions

### What is the biochemical hallmark of refeeding syndrome?

Hypophosphataemia, typically below 2 mg/dL within 12-72 hours of feeding, accompanied by hypokalaemia, hypomagnesaemia, salt and water retention, and thiamine depletion.

### Which children are at highest risk?

Severe acute malnutrition, negligible intake for five or more days, anorexia nervosa, rapid weight loss, or pre-existing electrolyte depletion — screened before any feeding plan.

### How is refeeding syndrome prevented?

Thiamine and B-complex before feeding, about 10-20 kcal/kg/day advancing over four to seven days, electrolyte correction, sodium and fluid restriction, daily monitoring in the first week.

### Why does WHO's F-75 formula embody refeeding caution?

It is deliberately modest in calories, low in protein, sodium and iron for the stabilisation phase, feeding the child at a rate the depleted cellular machinery can metabolise before catch-up feeding begins.

### How is established refeeding syndrome treated?

Reduce or pause feeds, correct phosphate (1-2 mmol/kg), potassium and magnesium with monitoring, give thiamine urgently, restrict fluids, and provide cardiac monitoring until electrolytes stabilise.