[Functional Dyspepsia].

Functional dyspepsia (FD) is defined as a clinical condition in which pain or discomfort arises from the gastroduodenal area in the absence of any organic, systemic, or metabolic disease that could explain the symptoms. Dyspeptic symptoms must be present for the previous three months with symptom onset at least six months before the diagnosis, according to the Rome IV criteria. Several factors have been suggested to induce the symptoms of FD, including disturbed gastroduodenal motility, visceral hypersensitivity, brain-gut interactions, duodenal low-grade mucosal inflammation, immune alteration, genetic susceptibility, and gut microbiota dysbiosis. Moreover, many patients with FD complain that specific foods trigger their symptoms, but the relationship between dietary or lifestyle factors and FD must be fully elucidated. Against this background, the Diet, Obesity, and Metabolism Research Study Group of the Korean Society of Neurogastroenterology and Motility developed visual materials outlining dietary and lifestyle factors relevant to functional gastrointestinal disorders to provide practical guidance for both clinicians and patients. This review introduces the FD section of these materials and provides a comprehensive summary of their contents.