Healthy and sustainable diet and physical activity – Methodological considerations and development of a combined summary score

Abstract

Background: Environmental sustainability and human health are connected through diets and physical activity. A major issue for the near future is how to feed the growing world population, expected to increase from today’s 7 billion to close to 10 billion people in 2050, without compromising planetary sustainability and the needs of future generations. Dietary shifts away from traditional diets, to diets rich in processed foods, meats, refined sugars, refined fats, and oils, contributes to the environmental strain, and also to enhanced incidence of chronic diseases, currently responsible for nearly two thirds of all deaths worldwide. Another major public health challenge is that one third of adults and four-fifths of adolescents do not reach recommended physical activity levels, causing approximately 6-10% of the non-communicable diseases of coronary heart disease, type II diabetes, breast- and colon cancer, and 9% of premature deaths. Moreover, passive transport activities in total produce about 23% of global climate gas discharges. In many countries an increased share of travels could be conducted as active transportation, representing a potential mean to decrease carbon footprint and increase levels of physical activity. Still, as various types of physical activity could provide equal health benefits yet different environmental impacts, the topical issues of sustainability and physical activity should be bridged in a broader sense than for active transportation.

The interactions between diet, physical activity, health and the environment advocates promotion of dietary and physical activity habits potentially causing minimal environmental damage and facilitation of healthy eating and healthy levels of physical activity. To measure degree of adherence to selected aspects they need to be operationalized. Yet, to our best knowledge, there is currently no combined summary score incorporating diet, physical activity, health and environmental considerations. Such a composite index may function as a measurement tool capturing relations between degree of adherence and different outcomes in future studies, or for monitoring time-trends. Besides, although dietary scores are increasingly used for exploring relations between dietary patterns and various health outcomes, there is a general lack of methodological examinations related to these summary scores.