Unfavorable food consumption in children up to school entry age: results from the nationwide German KiESEL study.

Introduction: Evidence points toward the early life being crucial for preventing nutrition-related diseases. As promotion of healthier food preferences in toddlerhood and preschool age might still modulate the trajectories of disease risk, understanding diet in these age groups is necessary. The objective was to analyze food consumption and diet quality of 1-5-year-old children living in Germany in relation to age and sex. Methods: Data from 890 children, a subsample of the representative, cross-sectional Children's Nutrition Survey to Record Food Consumption (KiESEL) conducted by the German Federal Institute for Risk Assessment in 2014-2017, were analyzed. Dietary data were collected using food records (3 consecutive plus 1 independent day). Diet quality was evaluated against the German food-based dietary guidelines (FBDG). Results: Consumption of unfavorable foods (e.g., sweets, soft drinks) exceeded the recommended maximum of 10% of energy intake (E%) by a multiple in all age and sex groups (medians: 24.8-35.8 E%). Preschoolers consumed more unfavorable foods than toddlers and boys more than girls. More than half of the children exceeded the recommendation for meat intake (medians: 2.3-3.2% of the total food consumption (%TFC) vs. 2 %TFC), especially preschoolers. In nearly all children, vegetable consumption was too low (medians: 4.2-4.5 %TFC vs. 12 %TFC). Also, milk/milk product consumption was below recommendations, more so in preschoolers (median: 12.0 %TFC ♂, 11.9 %TFC ♀ vs. 18 %TFC) than in toddlers (median: 16.1 %TFC ♂, 19.6 %TFC ♀). In toddlers and preschoolers with overweight or obesity, adherence to dietary recommendations of these food groups was largely similar to that of the total sample. Overall, 5-year-olds showed an unhealthier dietary pattern than 1-year-olds, which already emerged at age 2 years and became more evident at age 3 years. Discussion: An adverse dietary pattern arises and even deteriorates at a very young age, showing sex-specific aspects. High attention from public health and research needs to be given to toddlerhood and even earlier life phases, e.g., to develop more age-specific FBDGs, aiming at reducing unhealthy food consumption.

Unfavorable nutrient intakes in children up to school entry age: results from the nationwide German KiESEL study.

Background: Nutrition in the first years of life is a cornerstone for child development and long-term health, yet there is a lack of current data on energy and nutrient intake among toddlers and preschoolers in Germany. Objective: To analyze energy and nutrient intake in toddlers (1- to 2-year-olds) and preschoolers (3- to 5-year-olds) in Germany and compare the results with the Dietary Reference Values (DRVs) by the European Food Safety Authority. Design: Dietary intake was assessed by weighed food record data (3 + 1 day) of 890 children from the representative cross-sectional Children's Nutrition Survey to Record Food Consumption (KiESEL), carried out in 2014-2017 as a module of the German Health Interview and Examination Survey for Children and Adolescents Wave 2. For the calculation of energy and nutrient intake, the German Nutrient Database BLS 3.02, LEBTAB, and a supplement database were used. Results: Median intakes of energy and most nutrients met or exceeded the DRVs in both toddlers and preschoolers. However, low intakes relative to DRVs were found for vitamin D (6-9% of DRV, including supplements) and iodine (57-65% of DRV). Age specific downward deviations were observed for iron intake in toddlers (75% of DRV) and for calcium intake in preschoolers (67-77% of DRV). In contrast, intakes were high for saturated fatty acids (SFA) (14-16 E%), mono-/disaccharides (60-87 g/day), and protein [2.1-2.6 g/(kg body weight*day)]. Conclusion: Nutrient imbalances in toddlers and preschoolers in Germany, which are partly age-related, give rise to concern. Research is needed to determine if routine vitamin D supplementation should be extended beyond infancy. Public health efforts to increase the rate of use of iodized salt and to reduce the intake of SFA and mono-/disaccharides in children's diets are to be strengthened.

Adherence to food-based dietary guidelines among adolescents in Germany according to socio-economic status and region: results from Eating Study as a KiGGS Module (EsKiMo) II.

OBJECTIVE: Dietary habits developed during childhood and adolescence are likely to continue into adulthood. An unbalanced diet may cause nutrient deficiencies and excessive energy intake; these enhance the risk for developing overweight and obesity and their co-morbidities. In the present analysis, food consumption of adolescents is described and evaluated against German food-based dietary guidelines with special focus on socio-economic status (SES) and region of residence. DESIGN: Within the 'German Health Interview and Examination Survey for Children and Adolescents' (KiGGS Wave 2), the cross-sectional 'Eating Study as a KiGGS Module' (EsKiMo II) was conducted from 2015 until 2017 to provide data about dietary behaviour. SETTING: Germany. PARTICIPANTS: 1353 adolescents aged 12-17 years from a nationwide representative sample with food consumption data from computer-assisted dietary history interviews. RESULTS: The median consumption of fruits, vegetables, starchy foods and milk/dairy products among adolescents in Germany was below the recommendation. The median consumption of both meat/meat products and unfavourable foods, like confectionery, which should be consumed sparingly, was about 1·5 times the recommended amount. The total amount of beverages consumed by most adolescents was above the minimum amount recommended. Soft drink consumption of adolescents with a low SES was three to five times higher than soft drink consumption of adolescents with a high SES. CONCLUSIONS: The results indicate the need for an improvement of dietary habits among adolescents in Germany. Further approaches to promote healthy diets in Germany should be continued, and the focus on social inequalities should be strengthened.

Consumption of organic food by children in Germany - Results of EsKiMo II.

Data from the second Eating study as a KiGGS module (EsKiMo II, 2015-2017), are used to determine the contribution of food produced by organic farming (organic food) to the diet of children aged between six and eleven years (n=1,190) in Germany. Dietary intake was assessed by food records during a total of four days. Information on the proportion of organic food intake relative to daily food intake was used to differentiate between three groups: children who did not consume organic food; children whose diet contains 8.0% or less of organic food; and children whose diet comprises more than 8.0% of organic food. The 8.0% threshold represents the mean proportion of organic food eaten by children whose diet includes any amount of organic produce. In total, 63.2% of children eat organic food. The diet of 43.0% of children contains 8.0% or less of organic food, with the diet of 20.2% comprising more than 8.0% of organic food. Vegetables and fruit are among the most commonly consumed organic products. While consumption frequency of organic food does not differ by sex or age, consumption frequency increases with higher socioeconomic status. The large proportion of children (63.2%) who eat organic food suggests that health, environmental and ethical motives play a role in the food choices made by families with children.

Fast food consumption among 12- to 17-year-olds in Germany - Results of EsKiMo II.

Consuming high amounts of fast food can lead to an excessive intake of energy and subsequently promote obesity. Obesity increases a person's risk for diabetes and cardiovascular diseases. The second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2, 2014-2017) included the Eating study as a KiGGS Module (EsKiMo II, 2015-2017) which assessed the self-reported dietary habits of children and adolescents in Germany. The analysis of the data permits an overview of the fast food consumption of 12- to 17-year-olds (n=1,353). Girls consume 57.5 grams and boys 86.3 grams of fast food per day on average (around 400 grams and 600 grams per week, respectively). Pizza is the most consumed fast food product, followed by filled pita and sausage/meat products such as curry sausage. Adolescent girls on average get 6.5% and boys 7.8% of total daily energy intake from fast food. 23% of 12- to 17-year-olds get at least 10% of their daily energy intake from fast food (high consumers). Significant differences between the proportion of high consumers exist regarding sex, age, socioeconomic status, community size, type of school and media consumption. Compared to EsKiMo I (2006), girls' daily energy intake from fast food has remained nearly constant, whereas that of boys has dropped substantially. From a nutrition physiology perspective, the aim should be to further reduce fast food consumption.

Use of vitamin and mineral supplements among adolescents living in Germany-Results from EsKiMo II.

Dietary supplements may contribute to nutrient intake; however, actual data on dietary supplement use among adolescents living in Germany are rare. The aim of this analysis was to describe the current use of dietary supplements, its determinants, and reasons of use. Changes in supplement use over time were evaluated by comparing the results with those from EsKiMo I (2006). Data from the Eating Study as a KiGGS Module EsKiMo II (2015-2017) were used to analyze supplement intake according to sociodemographic, health characteristics, and physical exercise behavior of 12-17-year-olds (n = 1356). Supplement use during the past four weeks was assessed by a standardized computer assisted personal interview. Multivariable logistic regression was used to identify the association between supplement use and its determinants. Between 2015-2017, 16.4% (95%-CI: 13.0-19.7%) of the adolescents used dietary supplements, and its use decreased with lower levels of physical exercise and overweight. Most supplement users used only one supplement, often containing both vitamins and minerals. The most frequently supplemented nutrients were vitamin C and magnesium. The main reported reason to use supplements was 'to improve health'. Prevalence of supplement use was slightly lower in 2015-2017 than in 2006 (18.5%; 95%-CI: 15.8-21.2%). The results underline the importance of including nutrient intake through dietary supplements in nutrition surveys.

Associations between Physical Activity and Food Intake among Children and Adolescents: Results of KiGGS Wave 2.

A balanced diet and sufficient physical activity are essential for the healthy growth of children and adolescents and for obesity prevention. Data from the second wave of the population-based German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2; 2014-2017) were used to analyse the association between food intake and physical activity among 6- to 17-year-old children and adolescents (n = 9842). Physical exercise (PE) and recommended daily physical activity (RDPA) were assessed with self-administered questionnaires and food intake by a semi-quantitative food frequency questionnaire. Multivariable logistic regression was used to analyse the association between food group intake (dependent variable) and level of PE or RDPA. High levels of physical activity (PE or RDPA) were associated with higher consumption of juice, water, milk, dairy products, fruits, and vegetables among both boys and girls, and among boys with a higher intake of bread, potatoes/pasta/rice, meat, and cereals. Higher PE levels were also less likely to be associated with a high soft drink intake. High levels of RDPA were associated with high intake of energy-dense foods among boys, which was not observed for PE. This study indicates that school-aged children and adolescents with higher levels of physical activity consume more beneficial foods and beverages compared to those with lower physical activity levels.

[Breastfeeding behaviour in Germany-News from KiGGS Wave 2]. / Stillverhalten in Deutschland ­ Neues aus KiGGS Welle 2.

Breast milk is the optimal nutrition for babies in their first six months of life and provides health benefits for both children and mothers. As part of the Robert Koch Institute's health monitoring, the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) regularly collects population-based data on the health situation of children and adolescents living in Germany, including information on breastfeeding. This article describes breastfeeding behaviour based on the results of KiGGS Wave 2 (2014-2017). The prevalence of breastfeeding and the duration of breastfeeding in the birth cohorts 2009-2016 as well as information on intention to breastfeed and reasons for weaning are described. The results from KiGGS Wave 2 show that breastfeeding proportions for any type of breastfeeding tended to increase between the birth cohorts 2009/2010 and 2013/2014, while the prevalence for full and exclusive breastfeeding show no change. The average duration of breastfeeding has remained constant. Almost 90% of mothers intended to breastfeed their baby after birth and 97% of these mothers actually started breastfeeding. Having insufficient breast milk has often been mentioned as a problem, both by mothers who intended to breastfeed but did not start breastfeeding and by mothers who have been breastfeeding their infants for less than six months. Despite some limitations, the KiGGS study is an important part of breastfeeding monitoring. Regular data collection and the largely consistent study design make it possible to map trends in time and to measure the impact of breastfeeding promotion on the population. KiGGS Wave 2 shows that breastfeeding promotion measures are still necessary.

Overweight and obesity among children and adolescents in Germany. Results of the cross-sectional KiGGS Wave 2 study and trends.

For some time, there have been indications that the prevalence of overweight and obesity among children and adolescents in Germany has stabilised at a high level. The second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2, 2014-2017) once again provides nationwide measurements on height and weight of children and adolescents aged 3 to 17 years. The results are confirming this trend. The prevalence of overweight is 15.4% and 5.9% for obesity. There are no differences between girls and boys. Overweight and obesity prevalence increases with age. Children and adolescents with low socioeconomic status (SES) are more likely to be overweight and obese than those with high SES. Compared to the KiGGS baseline study (2003-2006), there was no further increase in overweight and obesity prevalence overall and in all age groups.

Updated prevalence rates of overweight and obesity in 4- to 10-year-old children in Germany. Results from the telephone-based KiGGS Wave 1 after correction for bias in parental reports.

The nationwide 'German Health Interview and Examination Survey for Children and Adolescents' (KiGGS), conducted in 2003-2006, showed an increase in the prevalence rates of overweight and obesity compared to the early 1990s, indicating the need for regular monitoring. Recently, a follow-up-KiGGS Wave 1 (2009-2012)-was carried out as a telephone-based survey, providing parent-reported height and weight from 5155 children aged 4-10 years. Since parental reports lead to a bias in prevalence rates of weight status, a correction is needed. From a subsample of KiGGS Wave 1 participants, measurements for height and weight were collected in a physical examination. In order to correct prevalence rates derived from parent reports, weight status categories based on parent-reported and measured height and weight were used to estimate a correction formula according to an established procedure. The corrected prevalence rates derived from KiGGS Wave 1 for overweight, including obesity, in children aged 4-10 years in Germany showed that stagnation is reached compared to the KiGGS baseline study (2003-2006). CONCLUSION: The rates for overweight, including obesity, in Germany have levelled off. However, they still remain at a high level, indicating a need for further public health action. What is Known: • In the last decades, prevalence of overweight and obesity has risen. Now a days, the prevalence seems to be stagnating. • In Germany, prevalence estimates of overweight and obesity are only available from regional or non-representative studies. What is New: • This article gives an update for prevalence rates of overweight and obesity amongst children aged 4-10 years in Germany based on a nationwide and representative sample. • Results show that stagnation in prevalence rates for overweight in children in Germany is reached.

EsKiMo II - the Eating study as a KiGGS Module in KiGGS Wave 2.

Nutrition plays an important role for health, in particular of children and adolescents. In addition to the baseline German Health Interview and Examination Survey for Children and Adolescents (KiGGS, 2003-2006), the nutrition survey EsKiMo (Eating study as a KiGGS Module) assessed the dietary habits of children and adolescents aged 6 to 17 in detail. In KiGGS Wave 2 (2014-2017) the corresponding module is EsKiMo II. Between June 2015 and September 2017, specially trained nutritionists will visit EsKiMo II participants at their homes. The parents of 6-to 11-year-olds are instructed on how to complete food records on four randomly chosen days - three consecutive days, followed later by an additional day. Participants aged 12 to 17 are interviewed personally on their food intake during the past four weeks with the dietary interview programme DISHES. Further information, for example, regarding dietary supplements is also recorded. EsKiMo II will provide an up-to-date and representative overview of the current nutrition status of 6-to 17-year-olds living in Germany, and it allows analysing changes in dietary behaviour over time. EsKiMo II can identify shortcomings in the nutrition of children and adolescents and thus may contribute with important information to nutrition and health policy.

Breastfeeding monitoring in Germany - What contribution can the data from KiGGS provide?

A continuous breastfeeding monitoring is essential as it enables reports on changes in breastfeeding behaviour. The German Health Interview and Examination Survey for Children and Adolescents (KiGGS), which is conducted by the Robert Koch Institute, periodically collects data about the health of children and young people living in Germany, including data on breastfeeding. Moreover, KiGGS is mentioned within the approach developed by the National Breastfeeding Committee as a possible source of data for breastfeeding monitoring. The data from KiGGS can be used to develop retrospective indicators on breastfeeding for particular birth cohorts. The data demonstrate that the prevalence of children who were ever breastfed tended to rise between the 2001/2002 and 2007/2008 cohorts; however, no significant changes were identified for the 2001-2008 cohorts with respect to breastfeeding duration. Breastfeeding monitoring relies on reports about current trends in the field; due to the periodicity with which the KiGGS study waves are conducted, data on current birth cohorts cannot be provided. Therefore, data on breastfeeding needs to be collected throughout Germany in relation to direct environmental and other factors. This data should be collected during health screenings and regular check-ups so that it can be used as a further measure in breastfeeding monitoring.

Prevalence of persons following a vegetarian diet in Germany.

People adopt a vegetarian diet for various reasons. A largely plant-based diet not only has advantages for health, it also has positive social and environmental aspects. The aim of this analysis is to provide a description of the people in Germany who follow a predominantly vegetarian diet and to compare their food consumption with those of non-vegetarians. As part of DEGS1 (2008-2011), a validated questionnaire was used within a representative sample of 6,933 persons aged 18 to 79 to study how often and how much of 53 different food groups was consumed during a four-week period. The questionnaire also included a question about a vegetarian diet. The data were analysed descriptively and with a binary-logistical regression model. In Germany, 4.3% of the population (6.1% of women and 2.5% of men) aged 18 to 79 usually follows a vegetarian diet. The highest proportion of vegetarians is found among 18- to 29-year-olds (women 9.2% and men 5.0%) and among women aged 60 to 69 (7.3%). People with a higher level of education are more likely to usually follow a vegetarian diet. The same applies to people who live in large cities and those who conduct more than four hours of sports per week. In addition, women and men who usually follow a vegetarian diet not only consume significantly less meat compared with non-vegetarians, they also drink less energy-reduced drinks, and less beer and wine; they also drink more tea and eat more fruit and vegetables. A vegetarian lifestyle is often associated with positive socio-political impacts. It can, among others, contribute to a reduction in factory farming, which means it can help preserve the environment. A reduction in meat consumption in Germany would also be beneficial from a public health perspective, since meat consumption is currently considerably higher than the amounts recommended by the German Nutrition Society. The benefits linked to a vegetarian diet would be further strengthened, if, in addition to the relatively small group of people who completely refrain from eating meat, a larger section of the population would reduce their meat consumption.

Updated prevalence rates of overweight and obesity in 11- to 17-year-old adolescents in Germany. Results from the telephone-based KiGGS Wave 1 after correction for bias in self-reports.

BACKGROUND: The nationwide "German Health Interview and Examination Survey for Children and Adolescents" (KiGGS), conducted in 2003-2006, showed an increase in the prevalence rates of overweight and obesity compared to the early 1990s, indicating the need for regularly monitoring. Recently, a follow-up-KiGGS Wave 1 (2009-2012)-was carried out as a telephone-based survey, providing self-reported height and weight. Since self-reports lead to a bias in prevalence rates of weight status, a correction is needed. The aim of the present study is to obtain updated prevalence rates for overweight and obesity for 11- to 17-year olds living in Germany after correction for bias in self-reports. METHODS: In KiGGS Wave 1, self-reported height and weight were collected from 4948 adolescents during a telephone interview. Participants were also asked about their body perception. From a subsample of KiGGS Wave 1 participants, measurements for height and weight were collected in a physical examination. In order to correct prevalence rates derived from self-reports, weight status categories based on self-reported and measured height and weight were used to estimate a correction formula according to an established procedure under consideration of body perception. The correction procedure was applied and corrected rates were estimated. RESULTS: The corrected prevalence of overweight, including obesity, derived from KiGGS Wave 1, showed that the rate has not further increased compared to the KiGGS baseline survey (18.9 % vs. 18.8 % based on the German reference). CONCLUSION: The rates of overweight still remain at a high level. The results of KiGGS Wave 1 emphasise the significance of this health issue and the need for prevention of overweight and obesity in children and adolescents.

Does breastfeeding help to reduce the risk of childhood overweight and obesity? A propensity score analysis of data from the KiGGS study.

BACKGROUND: Current studies suggest that the beneficial effect of breastfeeding on overweight and obesity may have been largely overestimated. We examined the relationship between >4 months of full breastfeeding and overweight/obesity in children living in Germany. METHODS: We analyzed retrospectively collected data on breastfeeding from children aged 3-17 years who participated in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS baseline study) between 2003 and 2006 (n = 13163). To minimize confounding, we applied propensity score matching and multivariate logistic regression analyses to estimate the effect of breastfeeding on childhood overweight and obesity. RESULTS: Adjusted analyses of the matched dataset (n = 8034) indicated that children who were breastfed for >4 months had a significant reduction in the odds of overweight (OR 0.81 [95% CI 0.71­0.92]) and obesity (OR 0.75 [95% CI 0.61­0.92]) compared to children who were not breastfed or who were breastfed for a shorter duration [corrected].Further analyses stratified by age group showed that the association was strongest in children aged 7-10 years (OR 0.67 [95% CI 0.53-0.84] for overweight and OR 0.56 [95% CI 0.39-0.81] for obesity), while no significant effect could be seen in other age groups. DISCUSSION: Our findings support the hypothesis that breastfeeding does have a beneficial effect on childhood overweight and obesity, although the effect seems to be strongest in children of primary school age.

Development and validation of correction formulas for self-reported height and weight to estimate BMI in adolescents. Results from the KiGGS study.

OBJECTIVE: The use of reported instead of measured height and weight induces a bias in prevalence rates for overweight and obesity. Therefore, correction formulas are necessary. METHODS: Self-reported and measured height and weight were available from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) baseline study (2003-2006) from 3,468 adolescents aged 11-17 years. With regression analyses, correction formulas for height and weight were developed. Cross-validation was conducted in order to validate and compare the formulas. Corrected BMI was calculated, and corrected prevalence rates were estimated. Sensitivity, specificity, and predictive values for overweight and obesity were calculated. RESULTS: Through the correction procedure, the mean differences between reported and measured height and weight become remarkably smaller and thus the estimated prevalence rates more accurate. The corrected proportions for overweight and obesity are less under-reported, while the corrected proportions for underweight are less over-reported. Sensitivity for overweight and obesity increased after correction. Specificity remained high. CONCLUSION: The validation process showed that the correction formulas are an appropriate tool to correct self-reports on an individual level in order to estimate corrected prevalence rates of overweight and obesity in adolescents for studies which have collected self-reports only.

[Mental health in adolescents in Germany: A comparison with regard to migration background and country of origin]. / Psychische Gesundheit von Jugendlichen in Deutschland : Ein Vergleich nach Migrationshintergrund und Herkunftsland.

Many children and adolescents in Germany grow up in families with a migration background. Different cultural, religious, and linguistic backgrounds have an influence on their behavior in various ways. Health status can be affected both negatively and positively by a migration background. The aim of this study was to analyze associations between migration background and self-reported psychological problems. In addition, it was tested whether country of origin had a differential effect on the associations found. Because of its migration-specific approach, the baseline survey (2003-2006) of the nationwide German Health Interview and Examination Survey for Children and Adolescents (KiGGS) offers a solid basis for migrant-specific analyses. Self-reported mental health problems were assessed using the Strengths and Difficulties Questionnaire (SDQ), which was completed by 6,719 adolescents aged 11-17 years. Adolescents with a two-sided migration background (i.e., both parents) reported higher SDQ total difficulties scores compared with adolescents without a migration background (16.9 vs 11.5%) or those with a one-sided migration background (16.9 vs 11.3%). Adolescents with a Turkish background had higher odds (boys: OR 2.0; 95%CI 1.3-3.2; girls: OR 2.0; 95%CI 1.2-3.4) of reporting mental health problems than adolescents without a migration background. Also, girls with a migration background from Western Europe, the USA or Canada had higher odds (OR 2.2; 95%CI 1.3-3.6). In some cases, adjusting for socioeconomic status led to insignificant associations with regard to the country of origin. The findings underline the importance of migrant-specific and culture-sensitive prevention, which also takes the environment and culture-specific characteristics into account.

Applying a correction procedure to the prevalence estimates of overweight and obesity in the German part of the HBSC study.

BACKGROUND: Prevalence rates for overweight and obesity based on self-reported height and weight are underestimated, whereas the prevalence rate for underweight is slightly overestimated. Therefore a correction is needed. Aim of this study is to apply correction procedures to the prevalence rates developed on basis of (self-reported and measured) data from the representative German National Health Interview and Examination Survey for Children and Adolescents (KiGGS) to (self-reported) data from the German Health Behaviour in School Aged Children (HBSC) study to determine whether correction leads to higher prevalence estimates of overweight and obesity as well as lower prevalence rates for underweight. METHODS: BMI classifications based on self-reported and measured height and weight from a subsample of the KiGGS study (2,565 adolescents aged 11-15) were used to estimate two different correction formulas. The first and the second correction function are described. Furthermore, the both formulas were applied to the prevalence rates from the HBSC study (7,274 adolescents aged 11-15) which are based on self-reports collected via self-administered questionnaires. RESULTS: After applying the first correction function to self-reported data of the HBSC study, the prevalence rates of overweight and obesity increased from 5.5% to 7.8% (compared to 10.4% in the KiGGS study) and 2.7% to 3.8% (compared to 7.8% in the KiGGS study), respectively, whereas the corrected prevalence rates of underweight and severe underweight decreased from 8.0% to 6.7% (compared to 5.7% in the KiGGS study) and from 5.5% to 3.3% (compared to 2.4% in the KiGGS study), respectively. Application of the second correction function, which additionally considers body image, led to further slight corrections with an increase of the prevalence rates for overweight to 7.9% and for obese to 3.9%. CONCLUSION: Subjective BMI can be used to determine the prevalence of overweight and obesity among children and adolescents. Where there is evidence of bias, the prevalence estimates should be corrected using conditional probabilities that link measured and subjectively assessed BMI from a representative validation study. These corrections may be improved further by considering body image as an additional influential factor.

Comparison of BMI derived from parent-reported height and weight with measured values: results from the German KiGGS study.

The use of parent-reported height and weight is a cost-efficient instrument to assess the prevalence of children's weight status in large-scale surveys. This study aimed to examine the accuracy of BMI derived from parent-reported height and weight and to identify potential predictors of the validity of BMI derived from parent-reported data. A subsample of children aged 2-17 years (n = 9,187) was taken from the 2003-2006 cross-sectional German KiGGS study. Parent-reported and measured height and weight were collected and BMI was calculated. Besides descriptive analysis, linear regression models with BMI difference and logistic regression models with weight status misclassification as dependent variables were calculated. Height differences varied by gender and were generally small. Weight and BMI were under-reported in all age groups, the under-reporting getting stronger with increasing age. Overall, the proportion for overweight and obesity based on parental and measured reports differed slightly. In the youngest age group, the proportion of overweight children was overestimated, while it was underestimated for older children and adolescents. Main predictors of the difference between parent reported and measured values were age, gender, weight status and parents' perception of the child's weight. In summary, the exclusive use of uncorrected parental reports for assessment of prevalence rates of weight status is not recommended.