Child Health, Agriculture and Integrated Nutrition (CHAIN): a randomized trial to close the nutrient gap in rural Zimbabwe Stunting (low height for a child's age) affects 155 million under-5 children around the world and leads to a higher risk of dying, poorer school performance and lower wages in adult life. Improving the quantity and quality of food for children under two years of age is the best approach we have to prevent stunting. We recently did a trial in rural Zimbabwe called SHINE, in which we showed that educating mothers about infant and young child feeding (IYCF) and giving the child a daily supplement (called Nutributter) to provide extra calories and vitamins, helped children grow taller. Despite this, many children still did not meet their daily nutrient requirements and over one-quarter remained stunted. In addition, the quantity of nutrients a child needs in developing countries is probably higher than in developed countries, because the gut is inflamed and less able to absorb nutrients. We therefore need to increase the nutrients children get and try to heal the gut, to help children grow better.   In this project, we will compare a new package of interventions against the SHINE approach, to see if we can close this nutrient gap. Almost 200 households with a 6-month-old child will be randomly allocated (like the flip of a coin) to receive the SHINE IYCF package (which we know reduces stunting) or the new package, which we call "IYCF-plus". Households receiving the SHINE IYCF package will receive 6 visits from a Village Health Worker to provide a series of lessons in how to feed a young child a healthy diet, including daily Nutributter. Households receiving the IYCF-plus package will receive an agriculture intervention and a more intensive feeding intervention. Families will receive three new varieties of crops (fortified maize, which is more resistant to drought and pests; moringa trees, which contain high amounts of protein, vitamins and calcium; and sugar beans, which contain easily digestible protein, zinc and iron) and will receive advice during planting and harvesting seasons. We hope this will increase the family's food availability, provide a more diverse range of food choices for the child and improve the nutrient content of the diet. The nutrients contained in these crops may also help the child's gut to heal, which should improve absorption of the food. Village Health Workers will visit households 12 times to give Nutributter and to provide more intensive messages about how to feed a young child, including use of the new crops. Families will also receive powdered versions of the crops that can immediately be used (for example, by adding to the child's porridge) before the family becomes self-sufficient by growing their own.  We will compare children in the IYCF and IYCF-plus groups at 18 months of age. The main outcome will be how many children in each group meet their daily nutrient requirements, using a detailed questionnaire that recalls and weighs all food the child ate in the previous day. We think that more children in the IYCF-plus group will meet their daily nutrient requirements.  We will also measure their height, weight, blood count, the amount of muscle and fat in the body, and collect blood, urine and stool samples. We will use these samples to measure nutrient levels in the blood (such as iron and protein), to study the body's metabolism (how certain nutrients are broken down and used), and to test our theory that the children in the IYCF-plus group will have a less inflamed gut.  If we show that the IYCF-plus intervention leads to better nutrient intake, a healthier gut, and higher levels of nutrients in the blood, we would expect the combined agriculture-infant feeding approach to improve children's growth more than the SHINE intervention did. This approach has the advantage of being sustainable because families can grow and process their own crops for the child to eat, and health workers in rural areas can provide the advice needed to ensure infants receive the food they need to grow. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.