F75 and F100 are specialized therapeutic milk formulas used to treat severe acute malnutrition (SAM) in children, as outlined by the World Health Organization (WHO) protocols. These are not ordinary formulas; they are carefully balanced to address the specific metabolic and nutritional needs of a severely malnourished child, whose body cannot tolerate normal feeding patterns. Proper administration requires medical supervision and a clear understanding of the two main phases of treatment.
The Two Phases of Inpatient Malnutrition Treatment
Phase 1: Stabilization with F75
F75 therapeutic milk is the foundation of the initial, or stabilization, phase of treatment. This phase is for children with SAM who have medical complications, severe edema, or a poor appetite. The body of a severely malnourished child has undergone a process of metabolic adaptation to conserve energy, and an abrupt, high-calorie refeeding attempt can be dangerous, potentially causing a fatal condition known as refeeding syndrome.
The primary goals of F75 feeding are to:
- Restore metabolic function cautiously.
- Correct severe electrolyte imbalances, particularly deficiencies of potassium and magnesium.
- Treat underlying infections, which are often present but may lack typical symptoms.
- Rehydrate slowly and cautiously.
To achieve these goals, F75 is a low-protein, low-lactose, and low-sodium formula that provides 75 kilocalories per 100 milliliters. This modest nutritional profile prevents overwhelming the child's fragile system. The initial phase with F75 typically lasts between 2 and 7 days, with small, frequent feeds given every two to three hours, day and night.
Phase 2: Rehabilitation with F100
Once a child has been successfully stabilized on F75, they can transition to the rehabilitation phase, where the primary objective is rapid weight gain and catch-up growth. The transition from F75 to F100 or a Ready-to-Use Therapeutic Food (RUTF) is signaled by several key indicators:
- The child's appetite has returned and is strong.
- Medical complications have resolved or are improving significantly.
- Any severe edema has started to disappear.
F100, which provides 100 kilocalories per 100 milliliters, has a higher content of protein, energy, and micronutrients to fuel the rapid growth required for recovery. In many settings, RUTF, a nutrient-dense paste, is now used in place of liquid F100 during this phase, especially for outpatient care, as it is ready-to-eat and does not require mixing with water. The rehabilitation phase can last for several weeks until the child reaches a healthy weight-for-height and is ready for a normal, healthy diet.
The Critical Transition from F75 to F100
The shift from F75 to F100 (or RUTF) is a crucial step that must be managed carefully over a two to three-day period. A gradual transition allows the child's gastrointestinal tract and metabolic systems to adapt to the increased energy and protein load, further mitigating the risk of refeeding syndrome. During this time, the child's intake is carefully monitored to ensure tolerance. The feeding amount is gradually increased from the F75 regimen to the higher volumes required for catch-up growth.
Comparison Table: F75 vs. F100
| Feature | F75 Therapeutic Milk | F100 Therapeutic Milk |
|---|---|---|
| Phase of Treatment | Stabilization (Phase 1) | Rehabilitation (Phase 2) |
| Primary Goal | Metabolic stabilization and cautious rehydration | Rapid weight gain and catch-up growth |
| Energy Content | 75 kcal per 100 ml | 100 kcal per 100 ml |
| Protein Content | Low (approx. 0.9 g per 100 ml) | High (approx. 2.9 g per 100 ml) |
| Lactose & Sodium | Low to prevent metabolic stress | Higher, to support growth |
| Indications | Medical complications, poor appetite, severe edema | Stabilized condition, good appetite, reduced edema |
Preparation and Administration
Both F75 and F100 formulas come in powdered form and must be reconstituted with boiled and cooled water under medical supervision to ensure the correct concentration and prevent bacterial contamination.
The standard preparation steps include:
- Using a measuring scoop provided with the formula.
- Adding the powder to the exact amount of cooled, boiled water.
- Mixing thoroughly to avoid clumps and ensure uniform nutrient distribution.
- Following the instructions for use on the product label precisely.
These therapeutic milks are strictly for supervised use in hospitals or therapeutic feeding centers, not for general community distribution. Continued breastfeeding is encouraged alongside these formulas when applicable. For outpatient treatment of uncomplicated SAM, RUTF is the standard, as it is ready-to-use and safer for home environments.
Conclusion: The Phased Approach to Recovery
The decision of when to give F75 and F100 is not arbitrary but is a critical component of a standardized, life-saving protocol for severe acute malnutrition. Starting with F75 ensures metabolic stability and prevents fatal complications, while transitioning to F100 provides the necessary energy for a strong recovery. This phased approach, combined with vigilant medical supervision, has dramatically improved outcomes for countless severely malnourished children globally. The use of these specialized formulas is a testament to evidence-based medical care in the fight against malnutrition.
For more information on the management of severe malnutrition, consult the Pocket Book of Hospital Care for Children from the National Center for Biotechnology Information.
