Katharina Diethelm

Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study

Background:Adequate sleep is a critical factor for adolescents health and health-related behaviors.Objective:(a) to describe sleep duration in European adolescents from nine countries, (b) to assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or inadequate food habits underlie this association.Design:A sample of 3311 adolescents (1748 girls) aged 12.5–17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece, Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study between 2006 and 2008. We measured anthropometric data, sleep duration, PA (accelerometers and questionnaire), television watching and food habits (Food Frequency Questionnaire).Results:Average duration of daily sleep was 8 h. Shorter sleepers showed higher values of BMI, body fat, waist and hip circumferences and fat mass index (P<0.05), particularly in females. Adolescents who slept <8 h per day were more sedentary, as assessed by accelerometry, and spent more time watching TV (P<0.05). The proportion of adolescents who eat adequate amounts of fruits, vegetables and fish was lower in shorter sleepers than in adolescents who slept ⩾8 h per day, and so was the probability of having adequate food habits (P<0.05). Correlation analysis indicated that short sleep is associated with higher obesity parameters.Conclusions:In European adolescents, short sleep duration is associated with higher adiposity markers, particularly in female adolescents. This association seems to be related to both sides of the energy balance equation due to a combination of increased food intake and more sedentary habits.

Food intake of European adolescents in the light of different food-based dietary guidelines: results of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

OBJECTIVE Since inadequate food consumption patterns during adolescence are not only linked with the occurrence of obesity in youth but also with the subsequent risk of developing diseases in adulthood, the establishment and maintenance of a healthy diet early in life is of great public health importance. Therefore, the aim of the present study was to describe and evaluate the food consumption of a well-characterized sample of European adolescents against food-based dietary guidelines for the first time. DESIGN The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, whose main objective was to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5-17·5 years. SETTING Ten cities in Europe. SUBJECTS The initial sample consisted of more than 3000 European adolescents. Among these, 1593 adolescents (54 % female) had sufficient and plausible dietary data on energy and food intakes from two 24 h recalls using the HELENA-DIAT software. RESULTS Food intake of adolescents in Europe is not optimal compared with the two food-based dietary guidelines, Optimized Mixed Diet and Food Guide Pyramid, examined in this study. Adolescents eat half of the recommended amount of fruit and vegetables and less than two-thirds of the recommended amount of milk (and milk products), but consume much more meat (and meat products), fats and sweets than recommended. However, median total energy intake may be estimated to be nearly in line with the recommendations. CONCLUSION The results urge the need to improve the dietary habits of adolescents in order to maintain health in later life.

Nutrient intake of European adolescents: results of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

OBJECTIVE An adequate nutritional intake in childhood and adolescence is crucial for growth and the prevention of youth and adult obesity and nutrition-related morbidities. Improving nutrient intake in children and adolescents is of public health importance. The purpose of the present study was to describe and evaluate the nutrient intake in a European sample using the D-A-CH nutrient intake recommendations and the Nutritional Quality Index (NQI). DESIGN The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, the main objective of which is to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5-17·5 years. SETTING Eight cities in Europe. SUBJECTS The initial sample consisted of 3528 European adolescents. Among these, 1590 adolescents (54% female) had sufficient and plausible dietary data on energy and nutrient intakes from two 24 h recalls using the HELENA-DIAT software. RESULTS The intakes of most macronutrients, vitamins and minerals were in line with the D-A-CH recommendations. While the intakes of SFA and salt were too high, the intake of PUFA was too low. Furthermore, the intakes of vitamin D, folate, iodine and F were less than about 55% of the recommendations. The median NQI was about 71 (of a maximum of 100). CONCLUSIONS The intakes of most nutrients were adequate. However, further studies using suitable criteria to assess nutrient status are needed. Public health initiatives should educate children and adolescents regarding balanced food choices.

Association between self-reported sleep duration and dietary quality in European adolescents

Evidence has grown supporting the role for short sleep duration as an independent risk factor for weight gain and obesity. The purpose of the present study was to examine the relationship between sleep duration and dietary quality in European adolescents. The sample consisted of 1522 adolescents (aged 12.5-17.5 years) participating in the European multi-centre cross-sectional ‘Healthy Lifestyle in Europe by Nutrition in Adolescence’ study. Sleep duration was estimated by a self-reported questionnaire. Dietary intake was assessed by two 24 h recalls. The Diet Quality Index for Adolescents with Meal index (DQI-AM) was used to calculate overall dietary quality, considering the components dietary equilibrium, dietary diversity, dietary quality and a meal index. An average sleep duration of ≥ 9 h was classified as optimal, between 8 and 9 h as borderline insufficient and < 8 h as insufficient. Sleep duration and the DQI-AM score were positively associated (β = 0.027, r 0.130, P< 0.001). Adolescents with insufficient (62.05 (sd 14.18)) and borderline insufficient sleep (64.25 (sd 12.87)) scored lower on the DQI-AM than adolescents with an optimal sleep duration (64.57 (sd 12.39)) (P< 0.001; P= 0.018). The present study demonstrated in European adolescents that short sleep duration was associated with a lower dietary quality. This supports the hypothesis that the health consequences of insufficient sleep may be mediated by the relationship of insufficient sleep to poor dietary quality.

Longitudinal associations between reported sleep duration in early childhood and the development of body mass index, fat mass index and fat free mass index until age 7

OBJECTIVE Epidemiological studies in children and adolescents have revealed short sleep duration as a risk factor for weight gain. However, only few studies have addressed sleep in early childhood. Our aim was to determine whether sleep in the second year of life is associated with the development of body composition throughout childhood. METHODS Analysis included 481 DONALD participants with parental reported data on sleep duration and annually measured body composition until age 7. Using median splits of sleeping time at 1.5 and 2 years we defined sleep duration categories: consistently short (CS, n = 122), inconsistent (I, n = 143) and consistently long (CL, n = 216). Polynomial mixed effects regression models were used to analyze differences in the trajectories of body mass index (BMI, kg/m(2)), fat mass index (FMI, kg/m(2)) and fat free mass index (FFMI, kg/m(2)) from ages 2-7 years between the sleep duration categories. RESULTS Compared to CL-children, CS-sleepers differed in their FMI development with respect to linear, quadratic and cubic trend (all p < 0.04), resulting in progressively higher FMI levels until age 7 independently of early life or socioeconomic factors. Trajectories of BMI and FFMI did not differ between the sleep duration categories. CONCLUSION Consistently short sleep duration in the critical window of early childhood appears to exert a moderate but sustained adverse effect on the development of fat mass - but not fat free mass - until age 7.

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.

Prospective relevance of dietary patterns at the beginning and during the course of primary school to the development of body composition.

Primary school years seem to represent a critical period for the development of overweight and obesity. However, only a few studies have analysed the prospective relationship between dietary patterns and weight status in children. The aims of the present study were to identify dietary patterns at the beginning of and during the primary school period and to examine their relevance to the development of body composition. Nutritional and anthropometric data from 371 participants of the Dortmund Nutritional and Longitudinally Designed (DONALD) Study at the beginning (ages 6 and 7 years) and end (ages 10 and 11 years) of the primary school period were used. Principal component analyses (PCA) were conducted to identify dietary patterns, which were regressed on changes in BMI and fat mass index (FMI) between ages 6 and 7 years and ages 10 and 11 years. Reduced rank regression (RRR) was used to directly extract patterns explaining variation in changes in BMI and FMI between ages 6 and 7 years and ages 10 and 11 years. PCA yielded interpretable patterns of dietary changes at the beginning of and during the primary school period, which were not related to changes in body composition. Conversely, RRR allowed identifying predictive patterns: higher baseline intakes of white bread and lower baseline intakes of whole-grain products as well as increases in the consumption of savoury snacks, sausages and cheese during primary school years independently predicted increases in BMI and FMI during the primary school period. In conclusion, selection of unfavourable carbohydrate sources at the beginning of the primary school period and increases in the consumption of processed savoury foods during primary school years may adversely affect the development of body composition during the course of primary school.

Food packaging cues influence taste perception and increase effort provision for a recommended snack product in children

Food marketing research shows that child-directed marketing cues have pronounced effects on food preferences and consumption, but are most often placed on products with low nutritional quality. Effects of child-directed marketing strategies for healthy food products remain to be studied in more detail. Previous research suggests that effort provision explains additional variance in food choice. This study investigated the effects of packaging cues on explicit preferences and effort provision for healthy food items in elementary school children. Each of 179 children rated three, objectively identical, recommended yogurt-cereal-fruit snacks presented with different packaging cues. Packaging cues included a plain label, a label focusing on health aspects of the product, and a label that additionally included unknown cartoon characters. The children were asked to state the subjective taste-pleasantness of the respective food items. We also used a novel approach to measure effort provision for food items in children, namely handgrip strength. Results show that packaging cues significantly induce a taste-placebo effect in 88% of the children, i.e., differences in taste ratings for objectively identical products. Taste ratings were highest for the child-directed product that included cartoon characters. Also, applied effort to receive the child-directed product was significantly higher. Our results confirm the positive effect of child-directed marketing strategies also for healthy snack food products. Using handgrip strength as a measure to determine the amount of effort children are willing to provide for a product may explain additional variance in food choice and might prove to be a promising additional research tool for field studies and the assessment of public policy interventions.

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.

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.