Thirty-six studies were included in the review. For chemosensory, cognitive and physical function only few studies were available, which reported inconsistent results regarding the relationship to dietary intake. In contrast, oral function was extensively studied in 31 studies. As oral factors general aspects of oral health like number of teeth, dental status (inadequate v. adequate), caries or wearing dentures were investigated. Additionally, some studies focused on functional aspects by
assessing chewing ability and bite force. Only one study considered also the aspect of swallowing function as a component of an oral health indicator. The different surrogate measures of oral function were associated with food as well as nutrient intakes including lower intakes of vegetables and fibre, and dietary variety. As all except six studies had a cross-sectional design, no causal relationships could be derived.