Cardiovascular prevention, including emphasising healthy diet and physical activity patterns for weight loss and diabetes prevention, is an important focus of primary care medicine, yet provision of intensive lifestyle counselling in the primary care setting remains uncommon. Online approaches for providing lifestyle counselling are emerging as a new avenue for bringing support to outpatient patient populations. Features of successful programmes include the use of a structured behavioural programme, electronic counselling support and feedback, and uncomplicated user interfaces. Online tools may be used independently or to complement in-person approaches. Limited data also suggest that the internet can be used to support the maintenance of weight loss. In addition, the internet may help overcome various clinical barriers to lifestyle support, including significant time limitations, a need to prioritise acute care and maintain clinical workflow, and the high cost of counselling. Furthermore, the continuity of the primary care patient–provider(s) relationship provides an established source of long-term support which has been difficult to create in other community settings. As the field of online lifestyle counselling matures, nutrition and physical activity experts will face new challenges in providing asynchronous counselling without the assistance of traditional non-verbal communication cues. However, the potential for reaching a wider population in a convenient and accessible manner also creates unique opportunities for providing lifestyle support.