Longitudinal trends in and tracking of energy and nutrient intake over 20 years in a Dutch cohort of men and women between 13 and 33 years of age: The Amsterdam growth and health longitudinal study.

The purpose of the present study was to describe the longitudinal development of nutrient intake and to determine the stability of this intake from adolescence into adulthood. Longitudinal data of the Amsterdam Growth and Health Longitudinal Study were analysed; the dietary intake of 200 subjects (males and females) was repeatedly measured (eight times) over a period of 20 years, covering the age period of 13-33 years. Dietary intake was determined with the detailed crosscheck dietary history interview. With use of multivariate ANOVA for repeated measurements, trends in macro- and micronutrients over time and differences between genders were analysed. Furthermore, stability coefficients, corrected for time-dependent (biological age) and time-independent covariates (gender) were calculated, taking into account all the measurements. The results showed significant time and gender effects for energy intake (kJ) and the following macronutrients: protein (g and % total energy supply), fat (g) and carbohydrate (g). Interaction effects between time and gender diminished when the macronutrients were calculated as a percentage of total energy intake. The micronutrients Ca, Fe and vitamins changed significantly over time and showed an interaction effect with gender, with the exception of cholesterol intake (mg/MJ), which did not show an interaction effect of time and gender. The tracking of the nutrient intake showed relatively low but significant stability coefficients for all macro- and micronutrients (0.28-0.52). In conclusion, dietary intake does change considerably over time, with the exception of polyunsaturated fat intake (% total energy supply) for both males and females and fat intake in females. Furthermore, stability coefficients for nutrients appeared to be low to moderate. Although these coefficients may be somewhat attenuated as a result of the relatively large measurement error of the dietary intake measurement, they suggest moderate stability of diet over time. These findings may imply that dietary intake is changeable and suggest that disease prevention measures can be implemented in adulthood.