• Weight gain during the 12-week follow-up (in grams)
  

• Length gain during the 12-week follow-up (in centimetres)
  
• Change in blood haemoglobin concentration during the study period (g/l)
  
• Change in serum ferritin concentration during the study period (µg/l)
  
• Change in anthropometric indices (WAZ, WHZ and HAZ)
  
• Proportion developing moderate or severe wasting during the intervention (WHM<80% of the reference median)
  
• Change in mid-upper arm and head circumference
  

Childhood undernutrition is very common in rural Malawi, like in many other countries in Sub-Saharan Africa. Usually, undernutrition develops between 6 and 24 months of age. By two years of age, 30-50% of all children in rural Malawi are undernourished, predisposing them to subsequent morbidity, developmental delay and mortality. Urgent interventions are needed but the magnitude of the problem precludes a hospital-based management strategy. Therefore, emphasis must be on prevention and early home-based rehabilitation of children with mild-to-moderate malnutrition. However, the options for community based approaches are not as developed as those for institutional management of undernutrition.

The present study tests a recently developed micronutrient fortified spread, FS, which offers a potential solution to home based nutrition rehabilitation. The concept has previously been shown to work not only in therapeutic feeding of undernourished children in nutrition rehabilitation units in Malawi but also home based supplementation of undernourished children aged 42 to 60 months in Mangochi District, southern Malawi. In the present study the investigators will test the efficacy in growth promotion of this product when provided as a supplementary food to moderately underweight, but not wasted, infants (defined as WAZ <-2, WHM=>80%) between 6 and 18 months of age.

The study will be conducted in Lungwena area, Mangochi District, rural Malawi. A total of 189 6-15 -month old infants will be enrolled and randomised to three groups receiving different daily food supplements for 12 weeks. Children in group one (control group) will not receive any supplementation, children in group two will receive 300 g FS weekly (43 g / day) and children in group 3 will received 500 g of fortified maize/soy flour weekly (71 g / day). The food supplements will be delivered to the participant's home at weekly intervals.

All children will undergo medical and anthropometric examinations at 6-weekly intervals and disease symptoms monitoring every week. Dietary intake assessments will be conducted at 9 weeks after the onset of supplementation. A blood sample will be collected at the beginning and end of the study to measure blood haemoglobin and serum ferritin concentrations.

The impact of the dietary interventions will be primarily assessed by comparing weight gain in the three intervention groups. Secondary outcomes include length gain and changes in blood haemoglobin and serum ferritin concentration. The study will also produce descriptive data on morbidity and intake of foods during the intervention.