Abstracts Plenary Session: Before the First 1000 Days: Before Conception and After Birth INFLUENCE OF EARLY NUTRITIONAL FACTORS ON OBESITY IN THE OFFSPRING L. Moreno1 1GENUD research group- Universidad de Zaragoza- Instituto Agroalimentario de Aragón IA2 - Instituto de Investigación Sanitaria de Aragón IIS Aragón- Centro de Investigación Biomédi ca en red de Fisiopatología de la Obesidad y Nutrición CIBEROBN- Zaragoza- Spain, Facultad de Ciencias de la Salud, Zaragoza, Spain Childhood obesity is the most prevalent nutritional disorder during childhood. It develops in individuals with a genetic predisposition substrate and the presence of factors related with nutrition, sedentary behaviours and others as short sleep duration. During early periods of life, starting at conception and until the end of the second year, there is a large number of factors that could influence the development of obesity later in life: pre-pregnancy maternal body mass index (BMI), gestational weight gain, gestational diabetes, maternal malnutrition, maternal smoking during pregnancy, alcohol consumption during pregnancy, free sugars intake during pregnancy, low polyunsaturated fat (omega 3) intake during pregnancy, low physical activity levels during pregnancy, antibiotics consumption during pregnancy, high or low body weight at birth, lack of breast feeding, consumption of high protein content infant formulas, rapid infant weight gain, high protein, fat or free sugars intake during infancy, early introduction of complementary feeding and short sleep duration. From all these candidate risk factors, the ones more strongly associated with obesity development during childhood are maternal obesity before pregnancy, low birth weight and rapid weight gain during infancy. Perinatal factors also influence the expression of some genes related with obesity development. For instance, birth weight modifies the effect of the FTO gene polymorphism in the development of obesity and breastfeeding also modulate the effect of the PPAR-gamma 2 gene polymorphism on the excess of adiposity in adolescents. Interventions trying to prevent obesity should start as early as possible as the possibility to positively influence the early programming of the condition is optimal in this period. Plenary Session: Before the First 1000 Days: Before Conception and After Birth NUTRITION, CONCEPTION AND THE OFFSPRING EPIGENOME M. Silver1 1MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Nutrition, London, United Kingdom Our group has a long-standing interest in exploring links between early life nutritional exposures and long-term health outcomes. Much of our research centres on a rural community in The Gambia in Sub-Saharan West Africa. A key focus is on epigenetics - the study of modifications to the genome that can affect gene expression without altering the underlying DNA sequence. Mounting evidence from animal and human studies suggests such modifications may mediate observed associations between early-life nutrition and later health and disease. For our epigenetic studies we are able to exploit an ‘experiment of nature’ in rural Gambia whereby fluctuations in energy balance and maternal nutritional exposures show a distinct bimodal seasonal pattern. We have shown for example that season of conception and blood levels of key maternal nutritional biomarkers relating to one-carbon metabolism (B2, B6, cysteine and homocysteine) predict DNA methylation in infants at a number of metastable epialleles (MEs) - genomic regions where methylation is established stochastically in the early embryo, leading to systemic (cross-tissue) inter-individual variation. I will give an overview of our work in this area and describe some of the interesting candidate MEs that we have selected for follow up in our population including a region at the POMC gene with links to obesity in children and adults. Plenary Session: Before the First 1000 Days: Before Conception and After Birth BREAST FEEDING AND GROWTH K.F. Michaelsen1 1Department of Nutrition- Exercise and Sports, University of Copenhagen, Denmark, Denmark Breastfeeding has a marked effect on early growth and there are some indications that there are also effects on growth later in life. Breastfed infants grow faster during the first 2-3 months and have thereafter a slower growth velocity up to the age of about 12 months, compared to infants that are not breastfed. This growth pattern, which is regarded as optimal, is also reflected in differences in body composition. There are studies suggesting a modest reduction in risk of obesity, but some studies show no effect. The vast majority of studies of the effect of breastfeeding on growth are observational and it is therefore difficult to conclude on causality as residual confounding and reverse causation are likely to influence the associations. There is an increasing number of studies examining the association between composition of breastmilk and growth of the infant. Especially the content of macronutrients, human milk oligosaccharides and appetite related hormones seem to have an effect on growth. A better understanding of these associations are likely to improve our understanding on how breastfeeding is regulating short and long term growth. Future studies should include analysis of milk composition and measurements of body composition when possible. Furthermore, data should also be analyzed according to sex as several studies have suggested that the association between milk intake and composition and growth is different in boys and girls. Plenary Session: Water, Sanitation and Hygiene (WASH) Interventions to Improve Child Health: Where Do We Go Now? PATHWAYS LINKING WASH AND GROWTH S. Sinharoy1 1Emory University, Environmental Health, Atlanta, USA The relationship between water, sanitation, and hygiene and child nutrition remains unclear, with mixed results from ecological and intervention studies. This presentation will provide an overview of key components of water, sanitation and hygiene (WaSH) and will outline the mechanisms and pathways through which WaSH may influence child nutritional status. Specifically, poor WaSH conditions may lead to diarrhea, environmental enteric dysfunction (a subclinical disorder of the small intestine), and intestinal parasitic infection. These in turn may result in undernutrition through appetite suppression, nutrient loss, malabsorption, and inflammation. Our understanding of these mechanisms provides a strong theoretical rationale for combining WaSH interventions to improve child nutrition. To illustrate how these relationships may operate in a real-world setting, the presentation will include results from a matched cohort effectiveness evaluation of a combined on-premise piped water and improved sanitation intervention in rural Odisha, India. We collected data in mid-2016 on anthropometry for children under age 5 (N=1826) in 45 intervention and 45 control villages. Children under age 5 living in communities that received the intervention had higher mean height-for-age z-score (HAZ) (+0.17 HAZ, 95% CI:0.03-0.31) compared to children in control villages. A structural modeling equation (SEM) approach quantified the direct and indirect intervention effects on HAZ through a complex system of divergent water, sanitation, and hygiene pathways. The results of the SEM analysis suggest that piped water and sanitation together influenced HAZ, and that both may be necessary for programs to impact child linear growth. Plenary Session: Water, Sanitation and Hygiene (WASH) Interventions to Improve Child Health: Where Do We Go Now? THE SHINE AND WASH BENEFITS TRIALS J. Humphrey1 1Johns Hopkins Bloomberg School of Public Health, International Health- Center for Human Nutrition, Baltimore, USA The WASH Benefits Bangladesh, WASH Benefits Kenya, and Sanitation Infant Feeding Efficacy (SHINE, Zimbabwe) trials were cluster-randomized controlled trials to test the independent and combined effects of improving household water and sanitation/hygiene (WASH) and improving infant diet on child stunting and anemia at 18 mo (SHINE) or 24 mo (WASH Benefits trials). In addition, 7-day prevalence of diarrhea at 12 and 18 or 24 months was a primary outcome of WASH Benefits and secondary outcome of SHINE. Together the three trials included more than 18,000 children; provided free pit latrines, soap, chlorine, and lipid-based micronutrient supplement; delivered behaviour change modules based on years of formative research and pilot testing, and grounded in behaviour change theory, and measured outcomes by standardized and supervised research staff. WASH Benefits included 7 arms [sanitation, handwashing with soap, point of use water chlorination, all these interventions combined (WASH), infant feeding, WASH+infant feeding, and a double sized control arm (passive in Bangladesh, active in Kenya)]. Thus, it was also designed to compare the benefits of single or combined WASH interventions. SHINE was a 2x2 factorial trials (WASH, Infant feeding, WASH+infant feeding, and an active control). In all three trials: • The interventions were delivered with high fidelity and achieved substantial behavior change; • The infant feeding intervention had a modest benefit but WASH had no effect on stunting; • The infant feeding intervention improved haemoglobin but WASH had no effect on haemoglobin concentration. In Bangladesh, all the intervention arms except water chlorination reduced diarrhea by a relative 30-40% from a very low prevalence (~5%); in the two Africa sites there