The purpose of F-75
F-75 is not a food meant for long-term nourishment or rapid weight gain. Instead, it serves a highly specialized and medically critical purpose: stabilizing a severely malnourished patient during the initial phase of treatment. At this stage, a child with severe acute malnutrition (SAM) is extremely fragile, with a weakened heart, compromised metabolism, and dangerously imbalanced electrolytes. Introducing high-calorie or high-protein food too quickly, a process known as refeeding, can overwhelm the patient's system and lead to a potentially fatal condition called refeeding syndrome. F-75 is precisely formulated to navigate this fragile state by providing a cautious and carefully balanced supply of energy and micronutrients.
The unique formulation of F-75
To understand how F-75 works, one must look at its nutritional composition, which is markedly different from standard nutritional formulas. The key lies in its low concentrations of protein, fat, and sodium, combined with a relatively high percentage of carbohydrates.
- High Carbohydrates, Low Osmolality: A starving patient has a compromised digestive system and reduced enzyme production. The high carbohydrate content, often including maltodextrin and sucrose, provides easily digestible energy. By maintaining a controlled osmolarity, F-75 reduces the osmotic load on the gut, which can be critical for children with diarrhea.
- Low Protein and Sodium: During prolonged starvation, the body's internal electrolyte balance is disrupted. Reintroducing normal levels of protein and sodium can cause severe electrolyte shifts, particularly of potassium, phosphate, and magnesium, as cells begin to synthesize new tissue. The low protein and sodium content of F-75 prevents this sudden, dangerous metabolic overload.
- Replenishing Micronutrients: F-75 is fortified with essential vitamins and minerals, excluding iron in the stabilization phase. The cautious withholding of iron is important because infections are common in malnourished children, and iron can fuel bacterial growth. Other crucial minerals like potassium and magnesium are included to correct deficiencies and prepare the body for the later rehabilitation phase.
The phases of SAM treatment and F-75's role
F-75's use is integrated into a multi-phase treatment protocol for severe acute malnutrition, as recommended by the WHO.
Phase 1: Stabilization
This is the initial hospital-based phase, where F-75 is exclusively used for a period of 2-7 days. The primary goals are to stabilize the patient’s metabolic function, correct electrolyte abnormalities, and treat any infections. Feeding is small and frequent, often administered every two to three hours. During this time, the patient is not expected to gain weight, and sometimes a slight weight loss occurs as edema subsides.
Phase 2: Transition and Rehabilitation
Once the child is stabilized, has regained their appetite, and has no remaining infections, they are transitioned to a different, higher-energy formula, such as F-100 or Ready-to-Use Therapeutic Food (RUTF). The transition phase, which lasts 1-3 days, involves gradually introducing the higher-calorie feed while monitoring for tolerance. The subsequent rehabilitation phase is aimed at achieving rapid weight gain and restoring normal growth.
Comparison of F-75 and F-100 therapeutic milks
F-75 and F-100 are both essential therapeutic foods, but their applications and compositions are vastly different. Using the wrong formula at the wrong time can have severe consequences, which is why F-75's specific purpose is so vital.
| Feature | F-75 Therapeutic Milk | F-100 Therapeutic Milk |
|---|---|---|
| Treatment Phase | Stabilization (Phase 1) | Rehabilitation (Phase 2) |
| Energy Density | 75 kcal per 100 ml | 100 kcal per 100 ml |
| Protein Content | Low (approx. 0.9g per 100 ml) | High (approx. 2.9g per 100 ml) |
| Fat Content | Lower percentage of total energy | Higher percentage of total energy |
| Sodium Level | Very low (max 17 mg/100ml) | Higher |
| Iron Content | Very low (max 0.05 mg/100ml) | Higher |
| Primary Goal | Stabilize metabolism, restore electrolytes | Facilitate rapid catch-up weight gain |
| Refeeding Syndrome Risk | Formulated to minimize this risk | Initiated only after metabolic stability achieved |
Conclusion
In essence, F-75 works by providing a safe, low-impact nutritional reset for a severely compromised body. It does not aim for immediate weight recovery but focuses on the more urgent, life-threatening metabolic and electrolyte abnormalities present in the initial stages of severe acute malnutrition. Its specific formulation is a cornerstone of the WHO's and other humanitarian organizations' treatment protocols, making a critical distinction between safe stabilization and potentially dangerous rapid refeeding. Its successful use allows patients to survive the initial crisis and eventually transition to more nutrient-dense formulas like F-100 for true rehabilitation and weight gain. Without this careful step, the risk of refeeding syndrome and other complications would make successful recovery far less likely.
