Abstract
The marked individual variability in response to common dietary exposures necessitates tailoring of dietary guidance to individuals, or small groups of individuals with similar needs, to optimize health. This is a complex task requiring integration of environmental, cultural, psychological, and biological contributions. Work in the area of precision nutrition is an effort to translate science into practice. A research roadmap developed through a National Institutes of Health conference identified many of the inputs that require quantification. Better characterization of ingestive behaviors is one key area. The aim of this narrative review is to summarize current understanding of the influences of age, sex, body mass index, ethnicity, and genetics on ingestive behaviors, including culture, sensory function, appetite, dietary intake, the gut-brain axis, and microbiome. To do so, the extant literature was accessed through search engines relevant to the various topics covered. Outcomes assessed varied topically. In addition to compiling evidence on the nature and magnitude of these relationships, this review highlights the degree of individual variability in attributes or responses to an intervention. More broadly, it documents: 1) that cause-and-effect relationships are difficult to establish as most are dynamic and interactive; 2) there are inherent and learned contributions to both behavior and biology that will require different considerations and offer different opportunities for manipulation; 3) a focus on intuitive approaches may not be as successful as desired; 4) that external influences can, and often do, override internal influences of biology; and 5) there are multiple ways to construct healthful diets. At the same time, it is vital that improved methods to characterize the multiple relevant inputs to ingestive behavior be developed. It is hoped that the evidence compiled here will inform efforts to develop precision nutrition guidance.