In the previous chapters we have considered nutrition as the relationship between food intake and health. We have examined the role of food components (nutrients and other substances), and we have seen how the total diet ultimately has an impact on health. The concept of balance is very important in understanding nutrition. It also drives much of the application of nutrition knowledge in practice.
Practice generally involves the use of tools. In this chapter we focus on core tools for nutrition practice that enable the principle of balance to be addressed. The key tools considered here are methods for assessing dietary intake, tools that enable translation of information on food intake to that of nutrients, and tools of dietary modelling, which incorporate knowledge from both dietary assessment and food composition.