Globally, overweight and obesity is a significant public health issue affecting more than 40 million children under the age of five in 2011. There is broad agreement around the aetiology of childhood overweight and obesity and risk factors have been identified prenatally, during pregnancy and early infancy. Clearly, from the point of view of the infant, risk factors that are present prenatally or during pregnancy are non-modifiable but those identified during infancy are potentially modifiable. Between 25%-33% of infants gain weight more rapidly than desirable during the first 6 months of life and this is the strongest risk factor for childhood overweight at 3 years. Rapid weight gain is potentially modifiable with interventions to facilitate better infant diet, feeding practices and exposure to physical activity. To facilitate identification of infants that might be at greater risk of developing childhood overweight and obesity a number of models have been developed. The Infant Risk of Obesity Checklist (IROC) was developed by the research team using data from the Millennium Cohort Study (MCS) and Avon Longitudinal Study of Parents and Children (ALSPAC) to potentially screen infants at 4 months of age for risk factors for childhood overweight and obesity at 3 years. However, it has not yet been tested in clinical practice.

Concerns have been expressed about using tools developed from the epidemiological literature to identify overweight and obesity risk where there are few effective evidence-based interventions for those affected. There is evidence that complex interventions targeting diet and feeding delivered to parents of infants \<2 years old show some positive intervention effects on feeding practices and physical activity, although many of these interventions do not tackle the psycho-emotional aspects of feeding and are not underpinned by behavioural change theory. The impact on weight outcomes is less certain, and in some cases this may be due to intervention components and behaviour change techniques targeted at the parent rather than infant level. Universal eligibility for overweight and obesity prevention is costly and may be unnecessary for those with a low baseline risk. However, targeting of certain groups where overweight and obesity is more prevalent (for example, lower socio-economic status, minority ethnic groups) has raised concerns around stigmatisation. Preliminary work with parents/legal guardians/carers suggests that targeting may be appropriate provided the person conveying the information has appropriate knowledge and sensitivity. his suggests a novel approach to such discussions is needed. Digital technologies are being used to provide information to patients about health care related areas. The findings of a recent review suggest that interactive multimedia programmes have the capacity to facilitate communication between health professionals and patients, but further research in this field is needed.

A pragmatic research design is planned with three linked phases. The first involved the development of an interactive multimedia programme, namely ProActive Assessment of Overweight Risk during Infancy (ProAsk) which includes the IROC and a therapeutic wheel, to facilitate health professionals' discussions with parents/legal guardians/carers about overweight risk and prevention during infancy. This phase is a feasibility study of the ProAsk intervention with parents/legal guardians/carers and health professionals. The study will gather information to inform the trial design and data collection procedures for a Randomised Controlled Trial (RCT) of overweight risk identification and intervention during infancy by UK health visiting teams.

The third phase will be conducted at the end of the feasibility trial .Qualitative work will be undertaken to determine the acceptability and utility of ProAsk with the health professionals working in a health visiting team and parents/legal guardians/carers.