In a 15 year longitudinal study (Amsterdam Growth and Health Study) is evaluated the effect of daily calcium intake (CAI) during adolescence and young adulthood on the development of peak bone mass at age 27 when the influence of weight-bearing activity (WBA) and body weight was accounted for. A group of 84 males and 98 females were measured longitudinally from age 13 until age 28. Measurements were taken six times of anthropometric characteristics. Lifestyle was also evaluated six times by cross-check interviews of CAI and WBA. Bone mineral density (BMD) of the lumbar spine was determined at age 27 by dual x-ray absorption. Three periods were considered, that is, the adolescent period, the period 13-21 years, and the total period (13-27 years). In multiple linear regression analyses, only WBA and body weight were significant positive contributors to the final model of lumbar BMD at age 27. In all three periods WBA was the best predictor in males and body weight in females. ANOVA was performed on BMD and the highest and lowest quartiles of calcium intake with the significant predictor variables of the linear regression model as covariates. Again calcium intake appeared not a significant predictor of BMD in the three periods in both sexes. Regular weight-bearing exercise and at least a normal age-related body weight in adolescence and young adulthood are of key importance in reaching the highest lumbar peak bone mass at the age of 27 years.

In 83 males and 99 females, the relation between peak strain physical activity (PSPA) from 13 to 27 years and lumbar bone mineral density (LBMD) at age 27 was studied. Physical activity was measured longitudinally by an interview six times between ages 13 and 27. Peak strain scores based on ground reaction forces were developed to quantify all registrated activities for peak strain. LBMD was determined once at age 27. Four PSPA periods were considered: the teenage period (13–17 years), the period between 13 and 21 years, the adult period (21–27 years), and the total period (13–27 years). In multiple linear regression analyses, with body weight and gender as covariates, PSPA appeared to be a significant positive predictor for LBMD at age 27 in both males and females for all analyzed periods. The explained variance of PSPA for LBMD was the highest (25%) for the total period and the lowest (8%) for the teenage period.

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Men and women with higher fitness levels consumed diets that more closely approached national dietary recommendations than their lower fit peers.

Objective: To illustrate issues related to under-reporting in dietary surveys relevant for development of food-based dietary guidelines Setting: Food and nutrient intakes in two national dietary surveys are analysed in relation to under-reporting using the concept of cut-off values for the ratio between energy intake and basal metabolic rate as well as biochemical markers of nutritional status. Results: Subjects with an implausibly low EI/BMR ratio had dietary patterns more close to recommended levels, e.g. lower fat intake and higher fibre intake, than those with acceptable energy intakes. Intakes of micronutrients were lower. This was due to both general and selective under-reporting of foods. Under-reporting was due to less frequent consumption, larger proportion of non-consumers and smaller portion sizes. Low EI/BMR ratios did not influence the characterisation of protein and micronutrient intake of low and high consumers of fruit and vegetable intake. Conclusions: Under-reporting can influence the usefulness of dietary data as a tool for developing food-based dietary guidelines, and the extent of under-reporting should be assessed using appropriate methods.

This article presents an overview of the Amsterdam Growth and Health Longitudinal Study (AGAHLS). This study was started in the 1970s, following a whole sample of 500 healthy 13-year-old boys and girls from two secondary schools. During the school period (12-17 years) annual measurements were performed with respect to anthropometrics, physiological and psychological parameters, lifestyle characteristics (activity, diet, smoking) and health parameters. A multiple longitudinal design was applied with overlapping birth cohorts and a cross-sectional measured control group to monitor for confounding factors such as time of measurement, cohort, dropout and testing effects. Emphasis is also placed on measures that enhance adherence of the subjects. The follow-up was extended with repeated measurements at age 21, 26 and 28. This enabled us to analyze the data with respect to tracking characteristics of biological and lifestyle variables over a period of 15 years between adolescence and adulthood and also to investigate quasi-causal relationships between the effects of a healthy lifestyle and indicators for cardiovascular diseases (CVD). Also new methods such as measurement of atherosclerosis and osteoporosis will be added and related to longitudinal measurements of the same subjects in the past. The main results that were obtained in the past are summarized and research questions for the near future are explained.

Objectives: Because of growing interest in the potential role of calcium in preventive pediatric strategies against osteoporosis, the longitudinal development and tracking of calcium and dairy intake from adolescence into adulthood was addressed. Design: In the Amsterdam Growth and Health Study, a group of 84 males and 98 females were followed over a 15 y period from age 13±27 y. The calcium and dairy intake was assessed six times by a cross-check dietary history method. To assess tracking, two traditional approaches, interperiod correlation coef®cients and percent of subjects who remained in the same quartile of calcium intake over time, and a new approach based on generalized estimating equations were used. Results: The mean calcium intake was relatively high and increased over time (30%). The tracking of calcium and dairy intake from adolescence into adulthood was moderate in both sexes (for example the correlation for calcium was 0.43 in males and 0.38 in females). Conclusions: The predictability of calcium intake over time does not seem to be suf®ciently strong to identify teenagers who are likely to maintain an inadequate calcium intake in adulthood. Therefore, the identi®cation and treatment of subjects with a low calcium intake cannot be limited to the teenage period but should be extended into adulthood.

These data indicate that the DQ is reasonably accurate in young adults as a means of assessing the calcium intake from dairy products.