Dortmund Nutritional And Anthropometric Longitudinally Designed Research Articles

Diet costs and energy density in the diet of German children and adolescents

This study examined the association between energy density (ED, g/kJ) and diet costs (\[euro]/day) in a sample of 494 German children and adolescents aged 4-18 years using 1100 3-day-weighed dietary records from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study (open cohort study) and retail food prices of 341 empirically selected recorded food items including special brands. ED was negatively associated with diet costs (β=-0.20 kJ/g, P<0.0007) with a non-linear term (β=0.01 kJ/g*kJ/g, P=0.0440). Diet costs increased with age (β=0.32 yr, P<0.0001) with a negative non-linear term (β=-0.01 yr*yr; P<0.0001). In conclusion, the inverse association between diet costs and ED was more pronounced in the older than in the younger age groups and in low-ED diets than in high-ED diets. Higher % diet costs of fruit/vegetables could be compensated by lower % diet costs of meat/sausage to lower ED without increasing diet costs.

Increase in prevalence of adiposity between the ages of 7 and 11 years reflects lower remission rates during this period

What is already known about this subject? A considerable increase in the prevalence of overweight during the primary school years (7-11 years) has been reported. What this study adds? This reflects lower remission rates of excess body fat (i.e. the proportion of shifts from excess to normal body fat) between the ages of 7 and 11 years as compared with nearly balanced incidence and remission rates of excess body fat between the ages of 3 and 7 years. This study aimed to compare the age-specific balance between incidence and remission of excess body fat between the ages of 3-7 and 7-11 years using the data from a longitudinal study. Longitudinal analysis based on the data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study, an ongoing, open cohort study in healthy children, conducted in Dortmund, Germany. Excess body fat was defined by the sum of triceps and subscapular skin-fold measurements above the 90th reference percentile of the new German standard; overweight was defined using different national and international standards. The main outcome parameters were incidence and remission rates of excess body fat (n = 496) and overweight (n = 518) between the ages of 3 and 7 years and between the ages of 7 and 11 years. The incidence rates of excess skin-fold thickness between the ages of 3 and 7 years (4.2 [2.4, 6.2]%) and between the ages of 7 and 11 years (4.3 [2.6, 6.2]%) were almost identical. By contrast, remission rates were significantly lower during the age period of 7-11 years (primary school age) than during the age period of 3-7 years (pre-school age): 37.5 (21.9, 53.1%) compared with 72.3 (59.6, 85.1%). These data point to the low remission of excess body fat as an important driving force for the increasing prevalence of excess body fat in children between the ages of 7 and 11 years. Public health initiatives in children should encompass both primary prevention and interventions targeted at children already overweight at school entry.

Consumption of dietary salt measured by urinary sodium excretion and its association with body weight status in healthy children and adolescents

Highly processed foods such as convenience foods usually have a high salt content and therefore might indirectly act as adipogenic due to an increasing consumption of sugar-containing beverages (SCB). We examined the association between dietary salt and body weight status. We used data on urinary Na excretion as an indicator of dietary salt and BMI standard deviation score (BMI-SDS) and percentage body fat (%BF) of children and adolescents participating in the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) Study. Dortmund, Germany. Children and adolescents (n 364) who had at least two 24 h urine samples and two dietary records in the observational period between 2003 and 2009 were considered in our data analysis. Repeated-measures regression models revealed that urinary Na was positively associated with BMI-SDS (+0·202 SDS/g Na excretion at baseline; P < 0·001) and %BF (+1·303 %BF/g Na excretion at baseline; P < 0·01) at baseline in boys and girls. These associations remained significant after adjustment for SCB consumption and total energy intake. Furthermore, there was a positive trend between baseline Na excretion and the individual change in %BF in the study period (+0·364 increase in %BF/g Na excretion at baseline), which was confirmed after inclusion of SCB consumption or total energy intake. There was no significant association between the change in Na excretion and the concurrent change of either BMI-SDS or %BF in any model. Our results suggest that a high intake of processed salty foods could have a negative impact on body weight status in children and adolescents independently from their consumption of SCB.

24h-Sodium excretion and hydration status in children and adolescents - Results of the DONALD Study

To describe actual data on intake, sources, age and time trends of urinary sodium excretion and to analyze the potential association between urinary sodium excretion and hydration status respective beverage consumption in a sample of healthy German children and adolescents. Data of 1575 24h-urine samples and weighed dietary records of 499 children (249 boys) aged 4-18 years of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study collected in 2003-2009 were analyzed using linear mixed effects regression models. Free water reserve (FWR, measured urine volume (ml/24h) minus the obligatory urine volume (ml/24h)) was used as a marker for hydration status. Urinary sodium excretion was between 1.4g/day and 3.2g/day, showing a positive age trend but remained stable during the study period. In girls, there was a significant positive association between salt excretion and FWR (p=0.04). Per g/MJ urinary sodium excretion, beverage intake increased by 0.05g/MJ (boys) or 0.08g/MJ (girls). Hydration status was not affected by salt intake in this sample of healthy children and adolescents in a western life style, due to a compensatory increase in beverage consumption.

Direction of Associations between Added Sugar Intake in Early Childhood and Body Mass Index at Age 7 Years May Depend on Intake Levels ,

Dietary factors, especially during early childhood, have been discussed as potentially critical for the development of childhood overweight. This study evaluated associations between added sugar intake during early childhood and BMI and body fat at age 7 y. Analysis was based on data from 216 participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study. Life-course plots were constructed to evaluate the association between added sugar intake at different ages (0.5, 1, 1.5, and 2 y) and BMI SD score (BMI-SDS) and % body fat (%BF) at age 7 y. Multivariable analyses were performed for the periods identified as critical for later BMI and body fat. Added sugar intake at age 1 y and the change in intake levels during the second year of life emerged as potentially critical. At age 1 y, a higher total added sugar intake was related to a lower BMI-SDS at age 7 y [adjusted β ± SE: -0.116 ± 0.057 BMI-SDS/percent energy (%En) added sugar; P = 0.04]. Conversely, an increase in total added sugar in the second year of life (Δ%En between age 1 and 2 y) tended to be associated with a higher BMI-SDS (adjusted β ± SE: 0.074 ± 0.043 BMI-SDS/Δ%En added sugar; P = 0.09). No associations were observed with %BF. In conclusion, added sugar intake at low intake levels during early childhood does not appear to be critical for BMI and body fat at age 7 y. However, detrimental effects on BMI development may emerge when added sugar intakes are increased to higher levels.

Detailed exposure assessment of dietary furan for infants consuming commercially jarred complementary food based on data from the DONALD study.

Furan is a possible human carcinogen regularly occurring in commercially jarred complementary foods. This paper will provide a detailed exposure assessment for babies consuming these foods considering different intake scenarios. The occurrence data on furan in complementary foods were based on our own headspace-gas chromatography/mass spectrometry (HS-GC/MS) analytical results (n = 286). The average furan content in meals and menus was between 20 and 30 µg kg(-1), which is in excellent agreement with results from other European countries. Using measured food consumption data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study, the average exposures for consumers of commercially jarred foods ranged between 182 and 688 ng kg(-1) bw day(-1), with a worst case scenario for P95 consumers ranging between 351 and 1066 ng kg(-1) bw day(-1). The exposure data were then used to characterize risk using the margin of exposure method based on a benchmark dose lower confidence limit for a 10% response (BMDL10) of 1.28 mg kg(-1) bw day(-1) for hepatocellular tumours in rats. The margin of exposures (MOEs) were below the threshold of 10 000, which is often used to define public health risks, in all scenarios, ranging between 7022 and 1861 for average consumers and between 3642 and 1200 for the P95 consumers. Mitigative measures to avoid furan in complementary foods should be of high priority for risk management.

Relation of isoflavones and fiber intake in childhood to the timing of puberty

It has been suggested that phytoestrogens and dietary fiber can affect puberty timing. We examined whether intake of isoflavone and fiber in healthy white children before their pubertal growth spurt [age at take-off (ATO)] was associated with puberty timing. Multivariate regression analyses were performed in 227 DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study participants with 3-d weighed dietary records and information on potential confounders at baseline (1 and 2 y before ATO). In a subsample (n = 111), urinary isoflavones were determined in 24-h urine samples by gas chromatography-mass spectrometry analysis. Puberty timing was examined by using ATO and chronologic ages at pubertal stage 2 for breast development (B2) or gonadal development, peak height velocity (PHV), and menarche or voice break. Girls whose diet was in the highest dietary isoflavone tertile experienced Tanner stage 2 for breast development ap 0.7 y later and reached PHV ap 0.6 y later than did girls whose diet was in the lowest isoflavone tertile [age (95% CI) at B2: 10.7 y (10.4, 10.9 y) compared with 10.0 y ( 9.7, 10.3 y), respectively; P for trend = 0.04; age at PHV: 11.9 y (11.6, 12.2 y) compared with 11.3 y (11.0, 11.6 y), respectively; P for trend = 0.04; adjusted for body mass index z score and fiber intake]. In boys, dietary isoflavones were not associated with pubertal markers. Urinary isoflavone and dietary fiber intakes were not associated with pubertal markers. Girls, but not boys, with higher prepubertal isoflavone intakes appear to enter puberty at a later age. Fiber intake in this sample of healthy white girls and boys was not relevant for puberty timing.

Whole grain in children's diet: intake, food sources and trends

To quantify the intake of grain and whole grain, and their food sources, as well as to investigate the age and time trends over the last decade in a sample of German children and adolescents. Dietary records from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study were used for conducting this work. A total of 5067 3-day weighed dietary records of 821 2- to 18-year-old children and adolescents collected between 1997 and 2008 were analysed using linear mixed-effect models, in which the means of the data and the covariance structure (children of the family, repeated measurements) were modelled. Mean whole-grain intake was between 20 and 33 g/day in the sample and highest in 13-18 year olds. No whole grain intake was recorded in 19% of all dietary records. Total grain intake increased significantly with age (P<0.0001), even after adjustment for energy intake. Whole-grain intake (g/day) increased significantly with age in the unadjusted model (P<0.0001). This increase disappeared after adjustment for energy intake (P>0.05) and became a negative trend after adjustment for grain intake (P<0.01). There were no significant time trends during the study period. Bread had the highest effect on grain intake in the total sample (50%), followed by rice/pasta (21%), cake (13%), grain (9%), RTECs (5%) and muesli (2%). The whole-grain intake in this sample of German children and adolescents was far below the FBDG. The decreasing percentage of whole grain per grain intake with age contradicts the common concept of stable dietary habits during childhood and adolescents.

Longitudinal Associations between Endogenous Melatonin Production and Reported Sleep Duration from Childhood to Early Adulthood

Background/Aims: The study objective was to assess longitudinal associations between melatonin secretion and reported sleep duration from childhood to early adulthood. Methods: In the frame of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study, 24-hour melatonin secretion and average daily sleep duration were determined once during childhood (4–< 11 years), adolescence (11–<16 years) and early adulthood (16–19 years) in 52 participants (23 males/29 females) aged 4–19 years. The associations between (1) melatonin secretion and sleep duration in childhood (cross-sectional); (2) melatonin secretion in childhood and sleep duration in early adulthood (prospective), and (3) changes in melatonin secretion and concurrent changes in sleep duration from childhood to early adulthood (concurrent) were analyzed. Results: Melatonin secretion was associated with sleep duration in childhood (cross-sectional, 3.5 min/day/10 µg 6-hydroxymelatonin sulfate (6-OHMS)/day, p = 0.009) and tended to predict sleep duration in early adulthood (prospective, 9.8 min/day/10 µg 6-OHMS/day, p = 0.09). An individual increase in melatonin secretion between childhood and early adulthood was associated with a concurrent increase in sleep duration (concurrent, 6.9 min/day/10 µg 6-OHMS/day, p = 0.046). Conclusion: Our observational data suggest that pineal production of melatonin in childhood is correlated with alterations in sleep duration until early adulthood. Nevertheless, this observational evidence needs to be verified in clinical studies.

Breakfast trends in children and adolescents: frequency and quality

Although breakfast is important for obesity prevention and dietary quality, breakfast skipping is a common behaviour. Knowledge of changes in breakfast habits may provide potential behaviour targets for intervention programmes. The present study describes the actual data on trends in breakfast habits and composition. A total of 7800 3 d dietary records of 1081 participants aged 2-18 years collected between 1986 and 2007 in the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) Study were analysed using mixed linear models. Breakfast was eaten at 78 % of all record days; regular breakfast (breakfast was eaten on all three recorded weekdays) was eaten in 75 % of records. During the study period, the number of records with regular breakfast decreased significantly in 6-12- and 13-18-year-olds (P = 0·0084 and 0·0350, respectively). Of all breakfast meals, 62 % were bread meals and 21 % were ready-to-eat cereal (RTEC) meals. RTEC meals nearly doubled from the youngest to the oldest age group (P < 0·0001). During the study period, the percentage of bread meals decreased, whereas the percentage of RTEC meals increased (P < 0·0001). A higher percentage of RTEC meals than the bread meals was in accordance with the food-based guidelines (36 % v. 20 %, P < 0·0001), i.e. a breakfast including grain, dairy and fruit/vegetables. In the DONALD Study sample, a negative age and time trend in breakfast consumption was verified. Interventions regarding breakfast habits should be aimed at adolescents and should focus on fruit/vegetables.

Birth and early life influences on the timing of puberty onset: results from the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study

BackgroundEarly age at puberty onset may predispose an individual to many currently prevalent diseases, including cancer and adiposity. ObjectiveThe objective was to investigate whether early life exposures influence the timing of puberty, as defined by both early and late markers, in healthy German girls and boys. DesignTerm participants (n = 215; 49.8% female) of the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study, with sufficient repeated anthropometric measurements between 6 and 13 y to allow estimation of age at take-off of the pubertal growth spurt (ATO) and information on a variety of early life exposures, including birth weight, breastfeeding status, velocity of weight gain, and parental characteristics, were studied. Age at peak height velocity (APHV) and menarche were also considered. ResultsChildren who weighed between 2500 and <3000 g at birth were ≈7 mo younger at ATO than were the other children (β ± SE: −0.56 ± 0.20 y; P = 0.006). Children who had gained weight rapidly between birth and 24 mo (increase in weight SD score >0.67) experienced ATO 4 mo earlier than those who had gained weight normally (−0.34 ± 0.15 y; P = 0.02). Rapid weight gain was also associated with an earlier APHV (P = 0.0006) and, in girls, with an earlier menarche (P = 0.002). Adjustment for body mass index SD score or body fat percentage 1, 2, or 3 y before ATO did not account for these effects. ConclusionIn both boys and girls, intrauterine and early postnatal growth factors appear to influence both early and later markers of puberty onset independently of prepubertal body composition.

Benzene in infant carrot juice: Further insight into formation mechanism and risk assessment including consumption data from the DONALD study

Benzene was previously detected as a heat-induced contaminant in infant carrot juices. This study shows that carrot juice contains substances such as β-carotene, phenylalanine or terpenes that may act as precursors for benzene formation during food processing. As benzene exposure has been associated with childhood leukaemia and other cancers, this study aimed to provide a quantitative risk assessment. To accomplish this, we used measured food consumption data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study, along with survey data on benzene in different juice categories. The calculated exposures for infants between 3 and 12 months were low, with averages between 1 and 10 ng/kg bw/day, resulting in a margin of exposure above 100,000. The exposures were judged as unlikely to pose a health risk for infants. Nevertheless, carcinogenic contaminants should be reduced to levels as low as reasonably achievable. The focus should be set on improving the sterilization conditions.

Relative validity of a self-completion 24 h recall questionnaire to assess beverage consumption among schoolchildren aged 7 to 9 years

Drinking habits in children are associated with diet quality, but validated assessment tools for large-scale studies in young children are lacking. Therefore, we validated a self-completion 24 h recall questionnaire (RQ) focusing on beverage consumption with a 24 h weighed record (WR). Thirty-five voluntary participants from the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) Study cohort aged 7-9 years completed the RQ. The illustrated RQ required ticking the number of glasses of seven beverage categories consumed in five time intervals in the previous 24 h. As a reference, parents completed weighed records of their child's diet. Agreement between the RQ and WR was tested by classification into consumers and non-consumers (kappa coefficients, kappa), by the children's ability to estimate the exact beverage and total volume consumed (Wilcoxon signed-rank test, Spearman rank correlation), and by ranking children according to reported beverage volumes. The RQ and WR showed a good level of agreement for classifying participants into consumers and non-consumers of the single beverage categories (kappa values between 0.78 and 0.94). Correlation coefficients for the volume of the single categories ranged between 0.81 and 0.91. The total beverage volume was overestimated in the RQ, on average, by 114 ml (P = 0.015). Agreement in ranking into tertiles by beverage volume was moderate to good for juice/soft drinks (kappa = 0.44), milk (kappa = 0.57) and water (kappa = 0.70), but fair for the total beverage volume (kappa = 0.23). Our self-completion 24 h RQ could estimate the consumption of several beverage categories among young children at the group level, but quantification of total beverage volume was flawed.

Validation of energy requirement equations for estimation of breast milk consumption in infants

To test equations for calculating infants' energy requirements as a simple and reliable instrument for estimating the amount of breast milk consumed in epidemiological studies where test-weighing is not possible. Infants' energy requirements were calculated using three different equations based on reference data and compared with actual energy intakes assessed using the 3 d weighed dietary records of breast-fed infants from the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study. A sub-sample of 323 infants from the German DONALD Study who were predominantly breast-fed for at least the first four months of life, and who had 3 d weighed dietary records and repeated body weight measurements within the first year of life. Healthy, term infants breast-fed for at least 4 months, 0-12 months of age. The overall differences between measured energy intake and calculated energy requirements were quite small, never more than 10 % of total energy intake, and smaller than the mean variance of energy intake between the three days of recording. The equation of best fit incorporated body weight and recent growth, while the worst fit was found for the equation not considering body weight. Breast milk consumption in fully and partially breast-fed infants can be reasonably quantified by calculating the infants' individual energy requirements via simple equations. This provides a feasible approach for estimating infant energy intake in epidemiological studies where test-weighing of breast milk is not possible.

Relation of Dietary Glycemic Index, Glycemic Load, and Fiber and Whole-Grain Intakes During Puberty to the Concurrent Development of Percent Body Fat and Body Mass Index

The authors prospectively examined whether change in dietary glycemic index (GI), glycemic load (GL), fiber intake, or whole-grain intake during puberty is associated with concurrent change in percentage of body fat (%BF) or body mass index (BMI; weight (kg)/height)(2). Linear mixed-effects regression analyses were performed in 215 participants from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study (Dortmund, Germany) who possessed weighed 3-day dietary records and anthropometric data at puberty onset (defined by age at takeoff) and over the subsequent 4 years (1988-2007). Neither changes in dietary GI, GL, fiber intake, nor whole-grain intake were associated with concurrent changes in %BF throughout puberty (change in %BF: -0.03 (standard error (SE), 0.11) per standard deviation (SD) increase in GI (P = 0.8); -0.01 (SE, 0.11) per SD increase in GL (P = 0.9); 0.02 (SE, 0.14) per SD increase in fiber intake (P = 0.9); and 0.09 (SE, 0.13) per SD increase in whole-grain intake (P = 0.5)). Similarly, no concurrent associations were observed between these dietary factors and BMI SD scores. Associations of dietary GI with %BF and BMI SD score differed between overweight and normal-weight adolescents (for concurrent association, P for interaction was 0.03 for %BF and 0.08 for BMI SD score). Dietary GI, GL, and fiber and whole-grain intakes in healthy, free-living adolescents do not appear to be relevant to the development of %BF or BMI during puberty.

Association of prepubertal body composition in healthy girls and boys with the timing of early and late pubertal markers

BackgroundIt is controversial whether prepubertal body composition is implicated in the timing of puberty onset. ObjectiveThe objective was to investigate whether body composition in the 2 y preceding the start of the pubertal growth spurt—a marker of puberty onset—is associated with the attainment of early and late pubertal markers in healthy German boys and girls. DesignMultivariate-adjusted regression analyses were performed in 215 participants of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study for whom body mass index (BMI) and its components fat mass/height2 (FM/m2) and fat-free mass/height2 (FFM/m2) 1 and 2 y before the onset of the pubertal growth spurt (age at takeoff; ATO) and information on early life exposures were available. In addition, age at peak height velocity (APHV) and menarche were examined. ResultsHigher BMIs and FM/m2z scores 1 and 2 y before ATO showed modest associations with chronological age at ATO among girls only (girls: P for = trend 0.05–0.1, adjusted for early life factors; boys: P = 0.2–0.6). FFM/m2z scores were not related to age at ATO (P for trend = 0.5–0.8). Conversely, prepubertal BMI and FM/m2 more clearly predicted APHV and puberty duration (APHV minus ATO) in both sexes and age at menarche in girls (girls: adjusted P for trend <0.0001–0.03; boys: P = 0.01–0.046). ConclusionThis longitudinal study suggests that prepubertal body composition in healthy boys and girls may not be critical for the initiation of the pubertal growth spurt but instead affects the progression of pubertal development, which results in earlier attainment of later pubertal stages.

Consumption of sugar-sweetened beverages and its association with nutrient intakes and diet quality in German children and adolescents

In the present study the relationship of sugar-sweetened beverage (SSB) consumption with the intake of single nutrients and total diet quality in German children and adolescents was evaluated using a repeated-measures regression analysis model. We used dietary data from 7145 three-day weighed records of 1069 subjects aged 2-19 years participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study. Intake of macronutrients as percentage of total energy intake (%En), intake of micronutrients as percentage of German reference values (intake quality score) and nutritional quality index (NQI) as an indicator of diet quality were chosen as separate dependent variables. SSB consumption was positively associated with %En from carbohydrates (boys v. girls: +4.00 v. +4.09 En%/MJ from SSB) and added sugars (boys v. girls: +7.36 v. +9.52 En%/MJ from SSB) and negatively with %En from protein (boys v. girls: - 1.25 v. - 1.31 En%/MJ from SSB) and fat (boys: - 2.82 v. - 2.73 En%/MJ from SSB). With respect to micronutrients, SSB consumption was negatively associated with folate and Ca intake, for which mean intake levels were inadequate in girls. Absolute diet quality was negatively associated with SSB consumption, whereas the effect was larger for girls (boys v. girls: - 1.41 v. - 2.63 points of NQI/MJ from SSB). Overall, results show a diluting effect of SSB consumption on micronutrient intake and diet quality. This effect might be relevant especially in girls as the association with diet quality was larger and mean NQI levels were lower in comparison with boys.

The ‘Functional Muscle-Cartilage Unit’: A Reasonable Approach to Describe a Putative Relationship between Muscle Force and Longitudinal Growth at the Forearm in Children and Adolescents?

Background: Several reports give evidence that the perichondral ossificiation of bone tubes (modeling) strongly depends on muscular forces in children and adolescents. The present analyses intend to investigate the hypothesis that muscular forces also partly determine enchondral ossification and, therefore, longitudinal growth of bone tubes. Subjects and Methods: Analyses were based on a single cross-sectional investigation with peripheral quantitative computed tomography in 296 individuals (age 5–19 years) participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study. Results: Forearm length (FL) was correlated with body height in gender-related subgroups of prepubertal and pubertal individuals (rs between 0.76 and 0.86). Cross-sectional muscle area (MA) increased faster than FL and faster than cross-sectional bone area (BA) close to the distal growth plate in puberty. Close to the growth plate, longitudinal growth was faster than perichondral ossification in females. The ratio MA/BA (surrogate of pressure on the distal growth plate) was correlated with FL in prepubertal boys (r = –0.249, p = 0.043) and pubertal individuals (r = 0.153, p = 0.051). Conclusions: Results support the hypothesis that longitudinal growth precedes modeling at the distal forearm. Confounding variables such as puberty may modify the relationship between muscle forces and longitudinal growth at the forearm in boys.

Pattern of beverage consumption and long-term association with body-weight status in German adolescents – results from the DONALD study

In the present study the relationship between the consumption of different beverage groups and body-weight status in 5 years of study participation in German adolescents was investigated. We used anthropometric and dietary data from 3 d weighed records of 244 subjects between 9 and 18 years of age participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study. Only subjects with at least four out of six possible weighed dietary records were considered. A repeated-measures regression model (PROC MIXED) was used to analyse the effect of beverage consumption on body-weight status. BMI standard deviation scores (BMI-SDS) and body fat percentage (%BF) were chosen as the dependent variables. In boys, energetic beverage consumption was not associated with BMI-SDS or %BF, neither cross-sectionally nor prospectively. In girls, baseline consumption of energetic beverages did not predict baseline BMI-SDS, baseline %BF, or change in either variable over the study period. However, an increase in energetic beverage consumption over the study period was associated with an increase in BMI-SDS (+0.070 SDS/MJ increase in energetic beverage consumption; P = 0.01). Separate consideration of regular soft drinks and fruit juices revealed that, in girls, BMI-SDS increased with increased fruit juice consumption (+0.096 SDS/MJ increase in fruit juice consumption; P = 0.01), and to a lesser extent with regular soft drink consumption (+0.055 SDS/MJ increase in regular soft drink consumption; P = 0.08). In conclusion, these results suggest that an increase in energetic beverage consumption may result in weight gain, at least in adolescent girls.

Potential renal acid load in the diet of children and adolescents: impact of food groups, age and time trends

The impact of acid-base balance on health is widely accepted. Here, we describe the potential renal acid load (PRAL) in the diet of healthy German children and adolescents. The Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study is an ongoing longitudinal (open cohort) study (start 1985) collecting detailed data on diet, growth, development and metabolism in infants, children and adolescents. Research Institute of Child Nutrition, Dortmund. Seven hundred and twenty children and adolescents (351 boys and 369 girls), aged 3-18 years, provided 4187 yearly collected 3-day dietary records between 1995 and 2005. Mean daily PRAL was positive in all age/sex groups (6-21 mEq day-1), and significantly higher in boys than in girls after the age of 8 years, even when calculated as mEq MJ-1. Fruits, vegetables and potatoes had a negative impact on PRAL; cheese, dairy products, cereals/bread and meat/fish/eggs had a positive impact. In a mixed linear model, PRAL, expressed as mEq day-1 and mEq MJ-1, remained stable during the study period, since time trends of PRAL-relevant food groups countervail each other. PRAL intake (mEq MJ-1) was significantly positively associated (P < 0.0001) with fat intake (% of energy intake, %E), but negatively with carbohydrate intake (%E; P < 0.0001). The analysis of dietary habits in our sample of German children and adolescents showed a moderate excess of acidity. Especially older boys should be encouraged to eat more potatoes and vegetables as good sources of dietary alkalinity. The PRAL concept is compatible with current concepts for a healthy diet.