2.5. Sample Size Calculation
The main objective of the study was to compare four locally produced RUTFs with the standard peanut-based RUTF for acceptability and efficacy. For the efficacy study, we based our initial sample size estimates on an overall increase of 4 g/kg BW/day, the target set by the WHO. A sample size of 50 children per group would allow the detection of a 20% difference between control and intervention products, assuming a standard deviation (SD) of 1.6 g/kg BW, a study design effect of 1.0 (individual randomization), a significance of 0.05 and a power of 0.80.