Personal experience, learned eating behaviors, hormones, neurotransmitters, and genetic variations affect food consumption. The decision of what to eat is modulated by taste, olfaction, and oral textural perception. Taste, in particular, has an important input into food preference, permitting individuals to differentiate nutritive and harmful substances and to select nutrients. To be perceived as taste, gustatory stimuli have to contact specialized receptors and channels expressed in taste buds in the oral cavity. Gustatory information is then conveyed via afferent nerves to the central nervous system, which processes the gustatory information at different levels, resulting in stimulus recognition, integration with metabolic needs, and control of ingestive reflexes. This review discusses physiological factors influencing the decision of what to eat, spanning the bow from the recognition of the nutritive value of food in the oral cavity, over the feedback received after ingestion, to processing of gustatory information to the central nervous system.