Gastrointestinal Tolerance of Under-five Children With Severe Acute Malnutrition to ONS Compared to F-75/F-100

The primary outcome of the study is to identify gastrointestinal tolerance of under-five children with severe acute malnutrition to ready-to-drink high energy (1.5 kcal/ml) and standard energy (1 kcal/ml) oral nutrition supplement (ONS) compared to Formula-75/Formula-100. The secondary outcomes of the study are weight gain, electrolyte profile and plasma amino acid profile at the beginning and the end of stabilization phase. In this randomized, controlled trial, 108 patients with severe acute malnutrition will be enrolled. Patients are randomly assigned to 3 groups (Formula-75/Formula-100, high energy ONS, and standard energy ONS) to undergo a two-week treatment. In order to ensure an adequate intake, nasogastric-tube will be placed for home enteral nutrition for at least throughout the two-week study period. Parent or caregiver will be asked to record daily intake, vomit, and defecation score using Bristol stool chart.

The study compares 3 groups of nutrition intervention for severe acute malnourished children aged 6-59 months in terms of gastrointestinal tolerance (primary outcome) and weight gain, electrolyte profile, and amino acid profile (secondary outcomes). The gastrointestinal tolerance is examined by Bristol stool chart and vomit daily record during 14 days of intervention. Diarrhea is defined according to ESPGHAN, i.e. a decrease in the consistency of stools score (loose or liquid) and an increase in the frequency of evacuations (typically 3 or more in 24 hours). The duration of diarrhea, frequency of diarrhea, and consistency of each stool are recorded. Vomit will be counted as mean frequency of vomit per day during 14 days intervention. Volume of vomit is recorded. Only vomit due to milk intolerance is counted. Vomit due to irrelevant reasons, such as coughing and crying, will be excluded. To ensure accurate formula intake, nasogastric tube is placed and patient is admitted for observation for a few days, depending on clinical conditions. Patient is discharged to undergo home enteral nutrition after parent is trained to administer formula and to clean all feeding devices properly. Parents of group F-75/F-100 is trained to make F-75/F-100 at home with hygienic procedure. The volume of milk intake is recorded daily. Patient is advised not to eat food/drink milk other than the intervention formula. Protocol for formula advancement is as follows: * Calorie requirement is calculated by multiplying ideal weight with daily energy requirement (recommended daily allowance, RDA). * Ideal weight is the median weight for actual height based on WHO growth chart (weight for height/length). * Height age is the median age corresponding to actual height of patient, based on WHO growth chart (height/length for age) * The value of RDA is based on height age, which is 110 kcal/day for height age 0-12 months and 100 kcal/kg/day 1. On the first day: patient is given 50-75% of RDA (recommended daily allowance), the daily volume of formula (F75/standard energy ONS/high energy ONS) will be divided into 8 feeding sessions (every 3 hours). Complete blood count, electrolyte, and amino acid profile will be tested prior to administering formula. 2. On the second day: patient is given 75-90% of RDA as F75/standard energy ONS/high energy ONS. 3. On the third day: patient is given 100% of RDA as F100/standard energy ONS/high energy ONS. Serum electrolyte will be tested before administering formula. Should there be any electrolyte imbalance, the electrolyte level will be corrected according to the clinical guideline. Weight and height will be measured on the first day and day 14. Head circumference will be measured on the first day.