Poor dental status and chewing deficiencies have been associated with cognitive decline. Altered dietary habits and malnutrition have been suggested as linking mechanisms. The aim of the present review was thus to investigate if poor oral health, and in particular tooth loss and impaired masticatory function, may affect dietary selection and nutritional intake in older adults, and moreover, to assess if prosthodontic dental care may improve nutritional status. Extensive tooth loss may impair masticatory function. Several studies in older populations have shown that severe tooth loss and masticatory impairment are associated with limited consumption of various food types (especially fruits and vegetables), increased consumption of sugary and easy-to-chew foods, and lower dietary intake of fibre and vitamins. However, these findings are not consistently reported, due to methodological variation among studies, potential adverse causalities, and the multifactorial nature of food choices. On the other hand, a few interventional studies revealed that prosthetic rehabilitation of missing teeth, when accompanied by dietary counselling, may improve dietary habits and nutritional intake. Further research is required to improve current knowledge of these associations. Under the limitations of the current study, a functional dental arch of natural or artificial teeth is important for maintaining adequate chewing efficiency and ability, but this only partly contributes to food choices and nutritional status. The multifactorial nature of food choices necessitates the interprofessional collaboration of dental professionals, dietetics practitioners, and primary care providers to improve dietary habits and nutritional intake.