Children who are above healthy weight are more likely to be ill and to miss time off school. Being overweight in childhood can also sow the seeds for health problems in later life such as heart disease and diabetes. Most overweight children become overweight adults. One solution is to try to prevent children becoming overweight by intervening very early in life. The risk factors for childhood overweight are known and this project aims to facilitate parents' (and other carers') understanding about this for their infant and to enable them to access intervention. UK health visitors (public health nurses) will use an interactive, multimedia programme (Proactive Assessment of Overweight Risk during infancy (ProAsk)), with parents to calculate their infant's risk and to discuss strategies for risk reduction as appropriate. Health visitors will be trained to communicate obesity risk and in Motivational Interviewing techniques to enable them to offer intervention to parents of infants identified as at risk.