OBJECTIVE: The aim of this study was to conduct a longitudinal investigation of the associations between changes in dietary factors and changes in caries experience among Finnish children and adolescents participating in the Physical Activity and Nutrition in Children (PANIC) study. METHODS: Among 487 children included at baseline at the age of 6 to 8 y, 406 were reexamined at 2-y follow-up and 202 at 8-y follow-up. Food consumption, nutrient intake, and eating frequency were assessed using 4-d food records
diet quality was assessed using the Baltic Sea Diet Score
and eating behavior was evaluated using the Children's and Adult's Eating Behaviour Questionnaires. At baseline and 2-y follow-up, caries findings were recorded using the World Health Organization guidelines and at 8-y follow-up using the International Caries Detection and Assessment System criteria. Generalized linear mixed-effects regression analyses were used. RESULTS: Over 8 y from childhood to adolescence, improved diet quality (β = -0.017, P = 0.046) and increased consumption of butter and butter-oil mixtures (β = -0.009, P = 0.044) were associated with decreased caries experience. Increased number of snacks (β = 0.072, P = 0.032), increased consumption of sour milk products (β = 0.001, P = 0.039) and salty snacks (β = 0.006, P = 0.010), and increased calcium intake (β = 2.41 × 10 CONCLUSIONS: A healthy diet is vital for oral health among children and adolescents. Dietary behaviors developing from childhood to adolescence seem to be associated with caries experience in adolescence. Dietary counseling aimed at improving dental health from childhood to adolescence should include avoiding frequent snacking, strengthening healthy eating behavior, and composing good overall diet quality. KNOWLEDGE TRANSFER STATEMENT: Results of this longitudinal study showed how crucial a healthy diet is for oral health among growing children. Eating behaviors and enjoyment of food play also a role in maintaining good oral health. Research results can be used when planning dietary recommendations and health education for children and adolescents.