Open Access Highly Accessed Study protocol

Prevention of Overweight in Infancy (POI.nz) study: a randomised controlled trial of sleep, food and activity interventions for preventing overweight from birth

Barry J Taylor1*, Anne-Louise M Heath2, Barbara C Galland1, Andrew R Gray3, Julie A Lawrence1, Rachel M Sayers1, Kelly Dale1, Kirsten J Coppell4 and Rachael W Taylor4

Author Affiliations

1 Department of Women's and Children's Health, University of Otago, PO Box 913, Dunedin 9016, New Zealand

2 Department of Human Nutrition, University of Otago, PO Box 913, Dunedin 9016, New Zealand

3 Department of Preventive and Social Medicine, University of Otago, PO Box 913, Dunedin 9016, New Zealand

4 Edgar National Centre for Diabetes and Obesity Research, University of Otago, PO Box 913, Dunedin 9016, New Zealand

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BMC Public Health 2011, 11:942 doi:10.1186/1471-2458-11-942

Published: 19 December 2011

Abstract

Background

Rapid weight gain during the first three years of life predicts child and adult obesity, and also later cardiovascular and other morbidities. Cross-sectional studies suggest that infant diet, activity and sleep are linked to excessive weight gain. As intervention for overweight children is difficult, the aim of the Prevention of Overweight in Infancy (POI.nz) study is to evaluate two primary prevention strategies during late pregnancy and early childhood that could be delivered separately or together as part of normal health care.

Methods/Design

This four-arm randomised controlled trial is being conducted with 800 families recruited at booking in the only maternity unit in the city of Dunedin, New Zealand. Mothers are randomised during pregnancy to either a usual care group (7 core contacts with a provider of government funded "Well Child" care over 2 years) or to one of three intervention groups given education and support in addition to "Well Child" care: the Food, Activity and Breastfeeding group which receives 8 extra parent contacts over the first 2 years of life; the Sleep group which receives at least 3 extra parent contacts over the first 6 months of life with a focus on prevention of sleep problems and then active intervention if there is a sleep problem from 6 months to 2 years; or the Combination group which receives all extra contacts. The main outcome measures are conditional weight velocity (0-6, 6-12, 12-24 months) and body mass index z-score at 24 months, with secondary outcomes including sleep and physical activity (parent report, accelerometry), duration of breastfeeding, timing of introduction of solids, diet quality, and measures of family function and wellbeing (parental depression, child mindedness, discipline practices, family quality of life and health care use). This study will contribute to a prospective meta-analysis of early life obesity prevention studies in Australasia.

Discussion

Infancy is likely to be the most effective time to establish patterns of behaviour around food, activity and sleep that promote healthy child and adult weight. The POI.nz study will determine the extent to which sleep, food and activity interventions in infancy prevent the development of overweight.

Trial Registration

Clinical Trials NCT00892983

Prospective meta-analysis registered on PROSPERO CRD420111188. Available from http://www.crd.york.ac.uk/PROSPERO webcite