Considerable interest exists internationally in determining the effectiveness of obesity prevention initiatives that commence early in life. The Prevention of Overweight in Infancy (POI) study was a randomized controlled trial investigating whether additional guidance and support around sleep, breastfeeding, diet and physical activity would slow the rate of excessive weight gain from birth to two years of age. While POI is part of the Early Prevention of Overweight in CHildren (EPOCH) prospective meta-analysis collaboration of four similar Australasian trials, it is unique in having a sleep intervention arm and including multiparous as well as primiparous mothers. 802 women were recruited in late pregnancy and randomized to: 1) Sleep (education sessions antenatally and at 3 weeks targeting the prevention of sleep problems, followed by an intervention from 6 months postpartum targeting the treatment of sleep problems), 2) FAB (provision of a lactation consultant to promote breastfeeding to 6 months, and education sessions at 3, 5, 7, 9, 12 and 18 months targeting healthy eating, sedentary time and active play for families), 3) Combo (Sleep and FAB interventions) or 4) Control. All four groups received standard Well Child care from the provider of their choice (typically 8 consultations in the first two years of life). Retention was high with 85% of families still involved in the study at 2 years of age. Further data were collected at 3.5 years and data collection at 5 years is ongoing. Mean body mass index (BMI) did not differ at 2 years by intervention group but children in the sleep arm were significantly less likely to be obese (≥ 95th percentile) than those in the FAB group. FAB and Combo appeared to increase physical activity and reduce sedentary activity. Data on infant feeding, physical activity (accelerometry), sleep, and dietary intake (Food Frequency Questionnaire) will be presented.