Starchy foods: Human nutrition and public health

Abstract

Starch is the largest source of energy in our diet and also provides an essential supply of exogenous glucose to act as fuel for our brains and red blood cells. Despite this key role in human nutrition, in recent years starchy foods have come to be viewed negatively, as consumption of large quantities of heavily processed starch has been epidemiologically linked to a number of negative health outcomes such as diabetes and obesity. A key aspect of the role dietary starch plays in the development of these conditions is the physical structure of the starch and the rate and extent of its digestion in the digestive tract. Starches with structures which are more rapidly digested are those most closely linked with the development of disease. Conducting human intervention trials with starchy foods is expensive and time consuming, so a range of in vitro digestion models have been developed as alternatives. There have been significant advances in these models, both in terms of how closely they mimic key aspects of the human digestive system and in terms of kinetic analysis of data obtained from these models. In this book chapter, the main models used for measuring starch digestibility, and their uses, are reviewed. Additionally, these in vitro approaches are contrasted with in vivo methods for acute interventions, as well as the findings of chronic studies in starchy food consumption.