Accurately measuring consumption of food, drinks and supplements is fundamental to nutrition and health research, including surveillance, epidemiology and intervention studies. However, assessing food intake is an area that is fraught with challenges . Diet is inherently complex given that it is
a chronic and multifaceted phenomenon that changes over time and varies in relation to age, life stage
and many other factors. The challenges associated with assessing diet and nutrient intakes have led to
the productive area of research that is the focus of this issue of Nutrients.