Consumers report the “taste” of foods drives what they like and choose to consume. “Taste” or flavor is a complex chemosensory experience with multiple peripheral inputs (true taste, smell,  chemesthesis) carried centrally for perceptual integration and coupling with hedonic, reward, decisional, and satiety responses. In nasal and oral cavities, food/beverage chemicals need to reach and bind or stimulate receptors for transduction to nervous signals and transmission to the brain. Multiple factors drive variation in flavor perception and preference, which, in turn; influence diet behaviors, chronic diet-related diseases, and responses to diet interventions. These include: conditions that impede chemicals reaching chemoreceptors and influence function of chemosensory-related nerves (including COVID-19); genetic variation in chemoreceptors; interactions between internal and external environments to influence plasticity of chemosensensory systems; and age-related changes. Genetic variation in taste and flavor frames the interplay between early-life developmental and environmental influences on food preferences that carry into adulthood. Aging, with changing experiences and environmental exposures, can modify flavor perception, with or without changes in food preferences and behaviors. Interdisciplinary and rigorous research should leverage sensory nutrition as markers of usual diet behaviors and preferences to improve understanding of variability in diet interventions. Clinical nutrition research should account for chemosensation in measures that reflect sensory function and self-reported function; and are relevant to food perception, including measures of food preference, to inform tailored nutrition interventions. Population-based research should incorporate feasible and informative measures of sensory nutrition and food preference with novel study designs to enhance understanding of diet-disease relationships and interindividual variability in dietary responses.