Purpose: To describe age and time trends in eating occasion frequency (EOF), meal frequency (MF), snack frequency (SF) and duration of nightly fasting (DNF) in German children and adolescents.
Methods: 9757 3-day dietary records of 1246 3-18-year-old participants of the open DONALD cohort study, collected 1985-2014, were analyzed for age and time trends using polynomial mixed-effects regression models. Eating occasions were either assigned to meals or snacks (>10 or ≤10 % of daily total energy intake per eating occasion). DNF was defined as the longest time span without energy intake within one night.
Results: EOF, MF and SF decreased with age (EOF: linear, quadratic, cubic trend p < 0.0001; MF: linear trend p < 0.0001; SF: linear, quadratic trend p < 0.0001). Time trend analyses revealed a wavelike time course for EOF (linear trend p = 0.0580, quadratic trend = 0.0039, cubic trend = 0.0015) and SF (linear trend p = 0.0055, quadratic trend p = 0.0005, cubic trend p = 0.0003). MF slightly increased until 2000 and decreased thereafter (linear trend p = 0.0012, quadratic trend p = 0.0047). Effect sizes of time trends in EOF, MF and SF were small. Boys' and girls' DNF decreased with age (in both: linear, quadratic, cubic trend p < 0.0001) and increased over the study period (boys: linear trend p = 0.0011, interaction of age and time p < 0.0001; girls: linear trend p = 0.0167).
Conclusion: EOF, MF and SF were higher in children than in adolescents, but, in contrast to other studies remained fairly stable over the study period. Decreasing DNF with age could reflect decreasing sleep durations. Additionally, DNF increased over the study period, probably due to an increase in breakfast skipping.
Keywords: Adolescents; Children; Eating frequency; Nightly fasting; Trends.