Public health nutrition research and practice often focuses on the assessment of dietary parameters, the determinants of dietary intake and related health outcomes. Physical activity assessment is arguably just as important a focus for research for an integrated and holistic approach to public health nutrition practice. This is particularly so in the context of the energy imbalance of the obesity era. In this issue, De Cocker et al.⁽Reference De Cocker, De Bourdeaudhuij and Cardon¹⁾ present a study comparing step count data from pedometers with self-administered questionnaires. They find that pedometer-based data offer adequate information to discriminate between levels of physical activity, but challenges exist and further work is needed to enhance the utility of physical activity assessment methods in practice.

Man has been modifying his foods for thousands of years, usually for human benefit but rarely closely monitored for adverse effects in a prospective manner. The current era of unprecedented food alteration, including functional foods, challenges us to monitor the food and nutrition system to enable assessments of the real effects of functional foods on population health. Beer-Borst et al.⁽Reference Beer-Borst, Costanza and Morabia²⁾ report on the development of a method to measure functional food consumption for risk factor surveillance. Hearty et al.⁽Reference Hearty, Duffy, Joyce, O’Connor and Gibney³⁾ report on a study of patterns of phytosterol intakes from enriched sources in the Irish population. With the expected future expansion of functional foods in the market, the ability to analyse the effect of functional foods on health outcomes (good and bad) is important.

Di Noia and Contento⁽Reference Di Noia and Contento⁴⁾ report on the criterion validity and user acceptability of a CD-ROM-mediated food record for measuring fruit and vegetable consumption among black adolescents in the USA. Iqbal et al.⁽Reference Iqbal, Ajayan, Bharathi, Zhang, Islam, Soman and Merchant⁵⁾ describe the refinement and validation of an FFQ for use in southern India. Both papers illustrate the importance of recognising the cultural and socio-economic nuances between populations when conducting dietary studies.

Conservation of the environment has recently become a focus for public, political and professional concern. The impact of the global food and nutrition system on the environment should be central to this concern. Nutritionists need to understand the environmental impacts of our dietary guidance and other interventions. Bere and Brug⁽Reference Bere and Brug⁶⁾ present a point of view suggesting that changes in our dietary behaviours which are sensitive to regional bioavailability and food culture can be both healthy and preserve the environment. They use a theoretically health-enhancing Nordic diet to illustrate this point, prompting readers to consider how environmentally friendly regional diets might look in our own parts of the world. In my part of the world where European food cultures have been imposed or exported onto the environment, this becomes quite a challenge. Not nutritionally or practically, but socio-culturally. Convincing the consuming public to swap roast beef for kangaroo or chicken for goanna will require all of the tricks of the advertising and marketing sector to sell this change. But I can’t see this happening, when there is much more profit to be made selling junk foods to children.