Nutrition education, in a public health context, is intended to influence large segments of the general population where they live, work and play. Educators face many challenges as they seek to engage people with varying degrees of interest and motivation in activities designed to change their eating habits. The intervention literature offers numerous examples of modest take-up rates and high levels of attrition. Such conditions argue for pursuing educational initiatives that are relatively brief and non-burdensome. At the same time, it is generally recognised that sufficient time and practice are needed for individuals to acquire the necessary information and skills, as well as to incorporate new behaviours into their life styles. Finding the optimal balance between these competing demands is at the core of the dosage question - how much nutrition education is enough for people to change dietary patterns?