Associations between dietary factors and obesity-related biomarkers in healthy children and adolescents - a systematic review

Background: The obesity prevalence in children and adolescents has increased worldwide during the past 30 years. Although diet has been identified as one risk factor for developing obesity in this age group, the role of specific dietary factors is still unclear. One way to gain insight into the role of these factors might be to detect biomarkers that reflect metabolic health and to identify the associations between dietary factors and these biomarkers. This would enable nutrition-related metabolic changes to be detected early in life, which might be a promising strategy to prevent childhood obesity. However, existing literature offers only inconclusive evidence for diet and some of these obesity-related biomarkers (e.g., blood lipids). We thus conducted a systematic literature review to further examine eligible studies that investigate associations between dietary factors and 12 obesity-related biomarkers in healthy children and adolescents aged 3-18 years. Methods: We searched the scientific databases PubMed/Medline and Web of Science Core Collection for potentially eligible articles. Our final literature search resulted in 2727 hits. After the selection process, we included 81 articles that reported on 1111 single observations on dietary factors and any of the obesity-related biomarkers. Results: Around 81% of the total observations showed nonsignificant results. For many biomarkers we did not find enough observations to draw clear conclusions on possible associations between a dietary factor and the respective biomarker. In cases where we identified enough observations, the results were contradictory. Since these nonsignificant and inconclusive findings may impede the development of effective strategies against childhood obesity, this article takes a closer look at possible reasons for such findings. In addition, it provides action points for future research efforts. Conclusions: In conclusion, current evidence on associations between dietary factors and obesity-related biomarkers is inconclusive. We thus provided an overview on which specific limitations may impede current research. Such knowledge is necessary to enable future research efforts to better elucidate the role of diet in the early stages of obesity development

A systematic review of vitamin D status in populations worldwide

Vitamin D deficiency is associated with osteoporosis and is thought to increase the risk of cancer and CVD. Despite these numerous potential health effects, data on vitamin D status at the population level and within key subgroups are limited. The aims of the present study were to examine patterns of 25-hydroxyvitamin D (25(OH)D) levels worldwide and to assess differences by age, sex and region. In a systematic literature review using the Medline and EMBASE databases, we identified 195 studies conducted in forty-four countries involving more than 168000 participants. Mean population-level 25(OH)D values varied considerably across the studies (range 4·9-136·2nmol/l), with 37·3% of the studies reporting mean values below 50nmol/l. The highest 25(OH)D values were observed in North America. Although age-related differences were observed in the Asia/Pacific and Middle East/Africa regions, they were not observed elsewhere and sex-related differences were not observed in any region. Substantial heterogeneity between the studies precluded drawing conclusions on overall vitamin D status at the population level. Exploratory analyses, however, suggested that newborns and institutionalised elderly from several regions worldwide appeared to be at a generally higher risk of exhibiting lower 25(OH)D values. Substantial details on worldwide patterns of vitamin D status at the population level and within key subgroups are needed to inform public health policy development to reduce risk for potential health consequences of an inadequate vitamin D statu

Role of contextual and compositional characteristics of schools for health inequalities in childhood and adolescence: protocol for a scoping review

Introduction: Childhood and adolescence are crucial life stages for health trajectories and the development of health inequalities in later life. The relevance of schools for health and well-being of children and adolescents has long been recognised, and there is some research regarding the association of contextual and compositional characteristics of schools and classes with health, health behaviour and well-being in this population. Little is known about the role of meso-level characteristics in relation to health inequalities. The aim of this scoping review is to retrieve and synthesise evidence about the mediating or moderating role of compositional or contextual characteristics of schools for the association between students' socioeconomic position and health in primary and secondary education. Methods and analysis We will conduct a systematic search of electronic databases in PubMed/Medline, Web of Science and Education Resources Information Center. Studies must meet the following inclusion criteria: (1) The population must be students attending primary or secondary schools in developed economies. (2) The outcomes must include at least one indicator for individual health, health behaviour or well-being. (3) The study must include at least one contextual or compositional characteristic of the school context and one individual determinant of socioeconomic position. (4) The study must also examine the mediating or moderating role of the contextual or compositional characteristic of the school context for the associations between socioeconomic position and health, health behaviour or well-being. (5) The study must be published since 1 January 2000 in English or German language. We will provide a narrative synthesis of findings. Ethics and dissemination We will not collect primary data and only include secondary data derived from previously published studies. Therefore, ethical approval is not required. We intend to publish our findings in an international peer-reviewed journal and to present them at national and international conferences

Identification of starting points to promote health and wellbeing at the community level – a qualitative study

Background: As health is influenced by the social, economic and environmental conditions in which individuals live, local communities are an ideal setting to promote health and wellbeing. However, up to now various health promotion interventions at the community level have had limited success, perhaps related to an incomplete understanding of local contexts and priorities. We therefore aimed to develop a broader and deeper understanding of topics or issues that were most salient to residents of a South-West German community by exploring their perceptions of needs, challenges, barriers and existing resources related to health and well-being. Methods: As an initial step of a multi-year community-based participatory research project, we conducted semi-structured interviews with key informants (n = 30) from various community settings (e.g., child care, elderly care, businesses, non-profit organizations, village councils, and local government). The terms “health” and “wellbeing” were included in the stem of each question in the semi-structured interview guide to enable a focus on related perceived needs, challenges, barriers and existing resources. Interviews were audiotaped, transcribed verbatim and analyzed using qualitative content analysis techniques. Results: Themes emerging from our interviews appeared to center primarily in three distinct areas: natural resources and built environment, access to services, and social cohesion including subthemes on the importance of social engagement and volunteerism, sense of community, and shared identity. Conclusions: That health and wellbeing were not identified explicitly as a priority by key informants suggests that these should not be presented as the primary focus of a community-wide initiative. Instead themes with a higher priority should be addressed in ways that can lead to better health and wellbeing as a secondary goal

Factors associated with serum 25-hydroxyvitamin D concentrations in older people in Europe: the EUREYE study.

BACKGROUND/OBJECTIVES: We aimed to describe serum 25-hydroxyvitamin D (25OHD) concentrations in older Europeans and to investigate associations between 25OHD and lifestyle factors, including dietary intake and supplement use. SUBJECTS/METHODS: Men and women aged ≥ 65 years were recruited from seven centres across north to south Europe. Serum 25OHD2 and 25OHD3 concentrations were measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) in 4495 samples and total 25OHD (25OHD2 + 25OHD3) was adjusted for season of blood collection. RESULTS: The mean (25th, 75th quartile) of seasonally adjusted 25OHD was 46 (34, 65) nmol/L, with the highest concentration of 25OHD in Bergen [61 (49, 79) nmol/L], and the lowest in Paris [36 (24, 57) nmol/L)]. Vitamin D deficiency (25-50 nmol/L) and vitamin D insufficiency (50-75 nmol/L) were found in 41 and 33% of the population, respectively. In multivariable analysis controlled for confounders, seasonally adjusted 25OHD concentrations were significantly (p < 0.05) lower in smokers and participants with self-reported diabetes and higher with increasing dietary vitamin D, and supplement use with fish liver oil, omega-3, and vitamin D. Additionally, in further analysis excluding Bergen, 25OHD was associated with higher intakes of oily fish and increasing UVB exposure. We observed low concentrations of 25OHD in older people in Europe. CONCLUSIONS: Our findings of the higher 25OHD concentrations in supplement users (omega-3 fish oil, fish liver oil, vitamin D) add to current recommendations to reduce vitamin D deficiency. We were unable to fully assess the role of dietary vitamin D as we lacked information on vitamin D-fortified foods

‘Oh God, I Have to Eat Something, But Where Can I Get Something Quickly?’—A Qualitative Interview Study on Barriers to Healthy Eating among University Students in Germany

Healthy eating can prevent individuals across all age groups from developing overweight/obesity and non-communicable diseases such as type 2 diabetes and cardiovascular disease. However, unhealthy eating habits (e.g., a high level of fast food consumption) have been found to be widespread among university students. Thus, it seems necessary to develop prevention strategies to improve students&rsquo; eating habits. However, to ensure that such strategies are successful, it is important that they fit the needs of the target population. By conducting qualitative interviews with students (n = 20), we aimed to get a deeper understanding of barriers to healthy eating. Students were asked about barriers to healthy eating and to suggest possible ideas that could improve their eating behavior in the future. Our findings revealed that students are especially affected by time-related barriers (e.g., a lack of time due to university commitment) and environmental barriers (e.g., a lack of cheap, tasty, and healthy meal options at the university canteen). Time-related barriers were also related to motivational barriers (e.g., being too lazy to cook after a busy day at university). In addition, knowledge/information-related barriers, social-support-related barriers, and transition-related barriers emerged from our interviews. The variety of barriers addressed and the different views on some of these, indicate that various strategies seem to be needed to improve the eating behavior among university students and to prevent them from gaining weight and developing non-communicable diseases in the future

Comparative physical activity as a global question to assess physical activity among university students

Background!#!To assess physical activity (PA), a comparative measurement - evaluating one's own PA compared to others - may be an appropriate method. In previous studies, the use of comparative measurements led to an effect known as unrealistic comparative optimism (UCO) - people being unrealistically optimistic about their behavior. Our aim was to use this comparative measurement in university students to quantify the prevalence of UCO at the group level and to draw conclusions on its validity.!##!Methods!#!We used data from the Nutrition and Physical Activity in Adolescence Study (NuPhA), a cross-sectional online survey that included only self-reports (n = 689). To assess PA among students, they were asked to rate their PA level compared to that of their same-aged fellow students. In addition, we used the Godin-Shephard leisure-time PA questionnaire and other questions on PA for comparisons. We used bivariate and cluster-based analyses to identify potential UCO.!##!Results!#!We found that UCO at the group level led to an uneven distribution, with a higher proportion of students who rated themselves as being more physically active than average. However, the individual assessment of PA with a single and simple comparative question seemed to be valid.!##!Discussion!#!A global single comparative question seems useful for studies where PA is measured as a covariate in university students