The objective of the present study was to explore the consistency of dietary choices made by children as they grow up. The dietary habits of 342 healthy children were reported annually from 5 to 13 years on a forty-five-item FFQ and analysed by factor analysis. The same two principal dietary patterns – ‘Healthy’ and ‘Unhealthy’ – emerged each year, and their consistency was assessed using Tucker's congruence coefficient (φ). Individual dietary z-scores for both of these patterns were then calculated every year for each child, and their consistency was measured by Pearson's correlation coefficient (r). Linear mixed-effects modelling was used to investigate individual trends and to quantify reliability of the individual dietary z-scores. Dietary patterns were moderately consistent and systematic over time (0·65 ≤ φHealthy ≤ 0·76; 0·62 ≤ φUnhealthy ≤ 0·78). Individual choices were also consistent year-on-year (0·64 ≤ rHealthy ≤ 0·71; 0·57 ≤ rUnhealthy ≤ 0·68). Reliability rose from 70 % with a single measure to over 90 % with four consecutive measures. The quality of diet diminished over time in 29 % of the children and improved in only 14 %. Dietary habits appear to be set early and seldom improve spontaneously.