BMC Public Health 2008, 8:103 http://www.biomedcentral.com/1471-2458/8/103 months), a positive impact on children's dietary intakes using similar approaches. The intervention will use an anticipatory guidance frame- work, to coincide with opportunities to support parents regarding feeding, physical activity and sedentary behav- iour issues for infants prior to their evolution. In addition, it will utilise the dynamics of existing first time parents' groups to support and reinforce the messages delivered in the intervention. Aims and Hypotheses The aim of the study is to test the effectiveness of an early childhood obesity prevention intervention delivered to first-time parents and focussed on parenting skills which support the development of positive diet and physical activity behaviours, and reduced sedentary behaviours in infants from 3 to 18 months of age. Study hypotheses In comparison to the control group infants, over the course of the intervention, the intervention group infants will:- Demonstrate greater increases in consumption of fruits and vegetables, and smaller increases in consumption of cordials, soft-drinks and juices and energy-dense snack foods. Demonstrate greater increases in time spent being phys- ically active and smaller increases in time spent in seden- tary behaviours, specifically TV viewing. Exhibit reduced incremental BMI gain. In comparison to the control group parents, the interven- tion group parents will demonstrate greater increases in:- the frequency with which they offer fruit and vegetables, water and milk (rather than cordials, soft-drinks and juices); and smaller increases in the frequency with which they offer energy-dense snack foods to their child; knowledge regarding infant eating, physical activity and sedentary behaviours and greater development of positive attitudes/beliefs regarding their capacity to influence these behaviours. the adoption of desired feeding strategies, including the division of responsibility in feeding and in providing opportunities for modelling of healthy eating. the adoption of strategies, including modelling, for increasing opportunities for physical activity and reducing opportunities for sedentary behaviours. Design and Methods Overall study design The INFANT study is a cluster- randomised controlled trial, with first-time parent groups within local govern- ment areas, as the unit of randomization (see Figure 1). The intervention will run from three to 18 months of age (currently funded; National Health and Medical Research Council Grant No. 425801) and additional funding will be sought for follow-up to assess sustainability of out- comes. Ethical approval to conduct the study has been granted by the Deakin University Ethics Committee (ID number:EC 175-2007) and by the Victorian Office for Children (Ref : CDF/07/1138). Participants and recruitment A two-stage random sampling process will be used to select first-time parent groups. At the first stage, twelve local government areas within a 60 km radius of the research centre (Deakin University in Burwood, Victoria, Australia) will be randomly selected. Local government areas within this geographical area that have an annual birth rate lower than 600 will be excluded. At the second stage, first-time parent groups within selected local gov- ernment areas will be randomly selected, proportional to the total number of first-time parent groups within each area. The first-time parents group currently underway will then be invited to participate. These first-time parent groups will be accessed initially via the MCH nurse who will set up an appropriate time to invite a member of the research team to speak with the group about the study. This team member will explain the study to the group and distribute research information packages. The packages will contain general study information, consent forms and contact details of the research team so any parent is free to contact the team to discuss any concerns or unan- swered questions. A majority of group members will be required to consent to allow the group to participate in the study. Non-consenting parents within participating groups will be permitted to attend the intervention ses- sions, but will not be required to provide data or be con- tacted by the research team in any other way. Inclusion criteria Parents will be eligible to participate if they are able to freely give informed consent, are first-time parents, mem- bers of a participating 'first-time parents group' and are able to communicate in English. Exclusion criteria Parents will be excluded from the study if they are unable to give informed consent or are unable to communicate in English. Infants with chronic health problems that are likely to influence height, weight, levels of physical activ- ity or eating habits will be excluded from analyses but will be permitted to participate in the study. Page 4 of 9 (page number not for citation purposes)