In order to gain better insight into meaningful effects of nutrition on immune function, there is a need for guidance on the assessment and interpretation of immune markers. However, there is no consensus as to which markers best represent the various aspects of immunity, including acute, chronic or low-grade inflammation. International Life Sciences Institute European Branch has commissioned several expert groups comprising individuals from different backgrounds including academia, government and the food industry to prepare descriptive and guidance documents on this topic. Two of these considered the markers of the immune response mainly in the context of host defence against pathogens, two considered general markers of inflammation, and one focussed on chronic low-grade inflammation in relation to overweight and obesity. This article describes the background to these documents and will summarise the work, findings and recommendations of the expert groups.