The association between dairy intake in adolescents on inflammation and risk markers of type 2 diabetes during young adulthood: results of the DONALD study.

OBJECTIVE: The aim of this analysis was to investigate whether habitual intake of total dairy (TD) or different dairy types (liquid, solid, fermented, non-fermented, low-fat, high-fat, low-sugar and high-sugar dairy) during adolescence is associated with biomarkers of low-grade inflammation as well as risk factors of type 2 diabetes in young adulthood. DESIGN: Multivariable linear regression analyses were used to investigate prospective associations between estimated TD intake as well as intake of different types of dairy and a pro-inflammatory score, based on high-sensitivity C-reactive protein, IL-6, IL-18, leptin and adiponectin, and insulin resistance assessed as Homeostasis Model Assessment Insulin Resistance in an open-cohort study. SETTING: Dortmund, Germany. PARTICIPANTS: Data from participants (n 375) of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study were included, for whom at least two 3-d weighed dietary records during adolescence (median age: 11 years) and one blood sample in young adulthood (>18 years) were available. RESULTS: There was no statistically significant association between TD intake or intake of any dairy type and the pro-inflammatory score (all P > 0·05). TD intake as well as each dairy type intake and insulin resistance also showed no association (all P > 0·05). CONCLUSIONS: The habitual intake of dairy or individual types of dairy during adolescence does not seem to have a major impact on low-grade systemic inflammation and insulin resistance in the long term. There was no indication regarding a restriction of dairy intake for healthy children and adolescents in terms of diabetes risk reduction.

Prospective association of family members' sugar-sweetened beverages intake with children's sugar-sweetened beverages consumption in China.

PURPOSE: We aimed to investigate whether parental and siblings' sugar-sweetened beverage (SSB) intake had prospective impact on children's SSB consumption, and the potential sex difference in these associations. METHODS: This study included a total of 904 children and their parents enrolled from 2004 to 2011 China Health and Nutrition Survey (CHNS) cohort study. SSB consumption information was estimated using a short dietary questionnaire and total energy intake was assessed with three-day 24-h dietary assessments at recruitment and follow-up surveys. Multivariate logistic or linear regression analyses were used to assess the association for SSB consumption between parents, siblings and children after adjusting for age, body mass index (BMI) z-score, household income and parental educational level. RESULTS: In this study, a majority (87.6%) of children consumed SSB. Among them, the median consumption of SSB was 70.3 ml/day per capita and 205.4 ml/day per consumer. Parental SSB consumption was relevant to children's SSB consumption, and this association was more pronounced in boys than in girls. Meanwhile, fathers seemed to have a stronger impact on whether children consume SSB than mothers which was reflected by lower P and higher OR. Additionally, children's SSB intake was prospectively associated with their older siblings' SSB consumption (P for trend < 0.03). CONCLUSIONS: Parental and older siblings' SSB consumption was relevant to children's SSB intake. Particularly, boys were more susceptible to parental impact than girls, and fathers seemed to have a greater influence on children than mothers.

Impact of lunch with carbohydrates differing in glycemic index on children's cognitive functioning in the late postprandial phase: a randomized crossover study.

PURPOSE: Studies about effects of lunch dietary Glycemic Index (GI) on cognition of schoolchildren are scarce. Our previous CogniDo GI study found no changes of cognition in the early postprandial phase after consumption of two rice types with medium vs. high dietary GI for lunch (i.e., 45 min after starting lunch). This study investigated whether the dietary GI of lunch has an impact on cognition of schoolchildren in the late postprandial phase, 90 min after lunch. METHODS: A randomized, 2 × 2 crossover intervention study was conducted at a comprehensive school with 5th and 6th grade students. Participants (n = 212) were randomly assigned to either sequence 1 or 2. In the first period, participants of sequence 1 received a dish with high GI rice (GI: 79), those of sequence 2 with medium GI rice (GI: 64)-in the second period, 1 week later, vice versa. Computer-based cognitive testing was performed 90 min after lunch examining tonic alertness, visual search and task switching, and working memory. Treatment effects and treatment effects adjusted for estimated lunch glycemic load (GL) were analyzed using a linear mixed model. RESULTS: The selected cognitive parameters were not affected by the GI of lunch 90 min after lunch, neither after intention-to-treat nor in the per-protocol analysis. Adjustment for GL also did not change results. CONCLUSION: The present study revealed no notable differences after the consumption of two rice types with medium vs. high dietary GI for lunch in children's cognitive function in the late postprandial phase, 90 min after lunch. CLINICAL TRIAL REGISTRATION: German Clinical Trials Register (DRKS00013597); date of registration: 16/04/2018, retrospectively registered.

Changes in patterns of eating habits and food intake during the first German COVID-19 lockdown: results of a cross-sectional online survey.

PURPOSE: The COVID-19 pandemic and public measures have a direct impact on the nutrition situation; studies show changes in food consumption, eating behavior or body weight but complex pattern analyses of changes rarely exist. METHODS: During the first German lockdown, a web-based survey was conducted among adults. It included 33 questions about changes in food intake, eating habits and physical activity, as well as anthropometrics and sociodemographic factors. Patterns of change were calculated based on changes in food intake and eating habits using two-step cluster analysis. To identify influencing factors for assignment to the patterns of change, binary logistic regression analyses were performed. RESULTS: Data from 2103 participants (81% female, 40 ± 14 years) were considered for analysis. Increased stockpiling, cooking, and variation in preparation was reported by 50-70%. The constant pattern (C-P, 36%) reported little change besides the above. The health-oriented pattern (HO-P; 37%) reported eating more healthy foods, avoiding unhealthy foods, and eating less and less frequently. The emotional-driven pattern (ED-P; 28%) exhibits higher influence of emotions on eating behavior, less avoidance of unhealthy foods, and increased consumption of sweets, pastries, and alcohol. The odds of changing eating behavior either to HO-P or ED-P were higher in women, people with migration background, younger participants, and increased with BMI categories. CONCLUSION: Both, the ED-P and HO-P, exhibit distinctive reactions in eating habits and food intake when dealing with a distressing experience. In subgroups, these may lead to disturbances in eating behavior and increase the risk for eating disorders and obesity.

Low leptin levels are associated with elevated physical activity among lean school children in rural Tanzania.

BACKGROUND: In Sub-Saharan African countries, rapid urbanization and increasing socio-economic status are associated with a transition to decreased physical activity (PA). A more sedentary lifestyle is linked to increased body fat leading to increments in leptin levels. Since rodent and human studies in high-income countries have shown that starvation-induced hypoleptinemia triggers high PA, efforts are warranted to pursue the hypothesis that low leptin levels in lean children of low- and middle-income countries (LMIC) are also associated with high PA. METHODS: In this cross-sectional study, we assessed seven-day PA with triaxial accelerometry (ActiGraph GT3X) among 223 primary school children (9 to 12 years of age) in rural Tanzania. Moderate-to-vigorous PA (MVPA) and total accelerometer counts per day were outcome variables. Leptin was determined using enzyme linked immunosorbent assay tests from dried blood spots. Anthropometric assessments were conducted and food insecurity and socio-demographic data were gathered using semi-structured interviews. RESULTS: In this sample of school children in rural Tanzania, leptin concentrations (median: 0.91 ng/mL, P25: 0.55, P75: 1.69), body mass index z-scores (median: -1.35, P25: -1.93, P75: -0.82), and height-for-age-z-scores (median: -1.16, P25: -1.96, P75: -0.61) were low. In contrast, PA levels were high with a median MVPA time of 119 min/day. Linear regression confirmed that leptin levels were negatively associated with MVPA (beta: -18.1; 95%CI: -29.7; -6.5; p = 0.002) and total accelerometer counts (beta: -90,256; 95%CI: -154,146; -26,365; p = 0.006). Children residing in areas with better infrastructure had lower MVPA levels (p < 0.001) and tended to have higher leptin levels (p = 0.062) than children residing in areas only reachable via dirt roads. CONCLUSION: Our cross-sectional field study is the first that supports the hypothesis of low leptin levels as a potential endocrine trigger of high PA in lean children of a LMIC. We observed early signs of a PA transition towards a less active lifestyle in a subgroup residing in areas with better infrastructure that concomitantly tended to have higher leptin concentrations. Considering that area-dependent PA differences were more pronounced among girls than boys, whereas differences in leptin levels were less pronounced, not only biological, but also external factors explain PA transition.

Rapid amelioration of anorexia nervosa in a male adolescent during metreleptin treatment including recovery from hypogonadotropic hypogonadism.

With this case report we support our medical hypothesis that metreleptin treatment ameliorates starvation related emotional, cognitive and behavioral symptomatology of anorexia nervosa (AN) and show for the first time strong effects in a male patient with AN. A 15.9 year old adolescent with severe AN of eight-month duration was treated off-label with metreleptin. Hyperactivity was assessed with accelerometry. Visual analogue scales (VAS), validated self- and clinician rating scales and lab results tracked changes from baseline to end of the 24-day dosing period and a five-month follow-up. Substantial improvements of mood and eating disorder related cognitions and hyperactivity set in after two days of treatment. During dosing, sub-physiological testosterone and TT3 levels normalized; clinically libido reemerged. Weight did not increase substantially during the dosing period. During follow-up target weight was attained; mood did not deteriorate; hyperactivity ceased. The results substantiate the strong effects seen in female cases and underscore the need for a double-blind placebo-controlled trial to confirm the observed strong, multiple and rapid onset beneficial effects of metreleptin in AN.

A mendelian randomization study on causal effects of 25(OH)vitamin D levels on attention deficit/hyperactivity disorder.

BACKGROUND: While observational studies revealed an inverse association between serum 25(OH)vitamin D (25(OH)D) and the risk of attention deficit/hyperactivity disorder (ADHD), the causality of this relationship remains unclear. METHODS: We conducted a bidirectional two-sample Mendelian Randomization (MR) study to examine whether 25(OH)D has an effect on the risk to develop ADHD or vice versa. Information on single nucleotide polymorphisms (SNP) associated with serum 25(OH)D was obtained from a genome-wide association study (GWAS) considering phenotype data from 79,366 individuals of European ancestry. Data on risk for ADHD were derived from a GWAS analysis with 20,183 individuals diagnosed with ADHD and 35,191 controls. For our analysis, we considered effect sizes based on the European participants (19,099 cases and 34,194 controls). RESULTS: Single SNP analyses showed a causal effect of vitamin D on ADHD risk for only one SNP (rs12785878, p = 0.024). The overall MR estimates did not reveal a causal effect of 25(OH)D on risk for ADHD. In the reverse analysis, neither any single nor the multi-SNP MR analyses showed a causal effect of ADHD on 25(OH)D. CONCLUSION: Results from this two-sample MR study did not confirm a causal effect of 25(OH)D on ADHD or vice versa. Accordingly, our study does not provide evidence that improving 25(OH)D via supplementation could reduce the risk of developing ADHD.

The overall diet quality in childhood is prospectively associated with the timing of puberty.

PURPOSE: The influences of nutrition in childhood on puberty onset could have sustained consequences for health and wellbeing later in life. The aim of this study was to investigate the prospective association of diet quality prior to puberty with the timing of puberty onset. METHODS: We considered data from 3983 SCCNG (Southwest China Childhood Nutrition and Growth) study participants with dietary data, anthropometric measurement, and information on potential confounders at their baseline assessment (mean age: 7.1 years for girls and 7.3 years for boys; mean length of follow-up was 4.2 years). Cox proportional hazard regression estimating hazard ratios (HRs) and 95% confidence intervals (CIs) were used to examine the relationship between diet quality and puberty onset. Dietary intake at baseline was assessed using a validated food frequency questionnaire. Diet quality was determined using the Chinese Children Dietary Index (CCDI) which measures adherence to current dietary recommendations (theoretical range: 0-160 points). Age at Tanner stage 2 for breast/genital development (B2/G2), menarche or voice break (M/VB) were used as pubertal markers. RESULTS: The CCDI score ranged from 56.2 to 136.3 for girls and 46.1-131.5 for boys. Pubertal markers consistently indicate that girls and boys with higher diet quality were more likely to enter their puberty later than their counterparts with lower CCDI scores (higher vs. lower CCDI tertiles: adjusted HR for age at B2: 0.85 (95% CI, 0.81-0.94), p for trend = 0.02; G2: 0.86 (95% CI,0.80-0.96), p for trend = 0.02; M: 0.86 (95% CI,0.80-0.95), p for trend = 0.02; VB: 0.86 (95% CI,0.79-0.98), p for trend = 0.03), after adjustment for paternal education level, baseline energy intake, and pre-pubertal body fat. CONCLUSIONS: Our data suggested a later puberty onset and later timing of progressed puberty stages in children with a high diet quality, which were independent of pre-pubertal body fat.

[Nutrition and mental health - how findings from genetic studies can support the identification of dietary effects]. / Ernährungseffekten auf der Spur ­ Wie die Genetik helfen kann, Zusammenhänge zwischen Ernährung und seelischer Gesundheit aufzudecken.

Nutrition and mental health - how findings from genetic studies can support the identification of dietary effects Abstract. Introduction: Numerous studies indicate that dietary interventions could be an important approach to the prevention and treatment of mental disorders. However, conventional nutritional epidemiological approaches (e. g., observational studies and randomized controlled trials, RCTs) have specific limitations to consider when interpreting the results. This article examines whether genetic studies could help to establish a link between diet and the prevention of mental disorders. Furthermore, it examines whether it is possible to draw conclusions about causal relationships. Methods: This narrative review describes various approaches of genetic cross-phenotype studies and presents examples of their applications in nutritional psychiatry. In addition, it discusses specific requirements as well as the strengths and limitations of the respective approaches. Results: To date, in the context of nutritional psychiatry, genetic correlation analyses, look-up analyses, and Mendelian randomization (MR) studies have been used for genetic crossphenotype analyses. Genetic correlation and look-up analyses provide initial evidence of possible overlap between specific mental disorders and metabolic pathways or specific nutrients. MR studies are used for detailed analyses that aim to identify causal relationships. However, MR is based on specific assumptions that must be met and considered when results are interpreted. Conclusion: Genetic cross-phenotype analyses are a useful amendment to conventional nutritional epidemiological research. In particular, positive results from MR studies provide an important fundament for identifying and developing suitable dietary interventions, which in turn increases the chance of success upon testing in subsequent RCTs. Accordingly, genetic cross-phenotype analyses are important instruments for increasing the efficiency in nutritional psychiatric research.

[Genetic Analyses of Complex Phenotypes Through the Example of Anorexia Nervosa and Bodyweight Regulation]. / Ebenen der genetischen Analyse komplexer Phänotypen am Beispiel der Anorexia nervosa und der Varianz des Körpergewichts.

Genetic Analyses of Complex Phenotypes Through the Example of Anorexia Nervosa and Bodyweight Regulation Abstract. Genetics variants are important for the regulation of bodyweight and also contribute to the genetic architecture of eating disorders. For many decades, family studies, a subentity of so-called formal genetic studies, were employed to determine the genetic share of bodyweight and eating disorders and found heritability rates exceeding 50 % with both phenotypes. Because of this significant contribution of genetics, the search for those genes and their variants related to the variance in bodyweight and the etiology of eating disorders - or both - was commenced by the early 1990s. Initially, candidate genes studies were conducted targeting those genes most plausibly related to either phenotype, especially based on pathophysiological considerations. This approach, however, implicated only a few genes in the regulation of bodyweight and did not provide significant insights into the genetics of eating disorders. Driven by considerable methodological advances in genetic research, especially related to the introduction of so-called genome-wide association studies by the beginning of the 21st century, today more than 1,000 variants/loci have been detected that affect the regulation of bodyweight. Eight such loci have been identified regarding anorexia nervosa (AN). These results as well as those from cross-disorder analyses provide insights into the complex regulation of bodyweight and demonstrated unforeseen pathomechanisms for AN.

Effect of vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients: results of a randomized controlled trial.

PURPOSE: While observational studies revealed inverse associations between serum vitamin D levels [25(OH)D] and depression, randomized controlled trials (RCT) in children and adolescents are lacking. This RCT examined the effect of an untreated vitamin D deficiency compared to an immediate vitamin D3 supplementation on depression scores in children and adolescents during standard day and in-patient psychiatric treatment. METHODS: Patients with vitamin D deficiency [25(OH)D ≤ 30 nmol/l] and at least mild depression [Beck Depression Inventory II (BDI-II) > 13] (n = 113) were 1:1 randomized into verum (VG; 2640 IU vitamin D3/d) or placebo group (PG) in a double-blind manner. During the intervention period of 28 days, both groups additionally received treatment as usual. BDI-II scores were assessed as primary outcome, DISYPS-II (Diagnostic System for Mental Disorders in Childhood and Adolescence, Self- and Parent Rating) and serum total 25(OH)D were secondary outcomes. RESULTS: At admission, 49.3% of the screened patients (n = 280) had vitamin D deficiency. Although the intervention led to a higher increase of 25(OH)D levels in the VG than in the PG (treatment difference: + 14 ng/ml; 95% CI 4.86-23.77; p = 0.003), the change in BDI-II scores did not differ (+ 1.3; 95% CI - 2.22 to 4.81; p = 0.466). In contrast, DISYPS parental ratings revealed pronounced improvements of depressive symptoms in the VG (- 0.68; 95% CI - 1.23 to - 0.13; p = 0.016). CONCLUSION: Whereas this study failed to show a vitamin D supplementation effect on self-rated depression in adolescent in- or daycare patients, parents reported less depressive symptoms in VG at the end of our study. Future trials should consider clinician-rated depressive symptoms as primary outcome. TRIAL REGISTRATION: "German Clinical Trials Register" ( https://www.drks.de ), registration number: DRKS00009758.

Risk factors for a low weight gain in the early stage of adolescent anorexia nervosa inpatient treatment: findings from a pilot study.

PURPOSE: Body weight restoration is a major treatment aim in juvenile inpatients with anorexia nervosa (AN) (i.e., 500-1000 g/week according to the German guidelines). Several studies suggest the early weight gain to be crucial for remission. The identification of patients at risk of a low early weight gain could enable an adequate adaptation of treatment. Thus, we aimed at detecting risk factors of a low weight gain during inpatient treatment. METHODS: The presented work analyzes data from a pilot study in 30 female adolescent inpatients with AN (restricting subtype; age range at admission: 12.6-17.6 years). Premorbid characteristics, history of symptomatology, anthropometric data, and eating-disorder psychopathology were compared between those who gained at least an average of 500 g/week during the first 7 weeks of treatment (high weight gainers, HWG) and those who did not (low weight gainers, LWG). RESULTS: At admission, LWG (n = 15) had a significantly higher BMI(-SDS) and scored significantly higher in the eating-disorder examination questionnaire (EDE-Q) than HWG (n = 15). A logistic regression analysis indicated both parameters to be independently associated with a low weight gain. CONCLUSION: Higher EDE-Q scores seem to be a major risk factor for a low weight gain at the beginning of treatment. Moreover, a higher BMI(-SDS) at admission does not necessarily indicate a less severe AN symptomatic, as it was associated with a lower weight gain in our sample during the first 7 weeks of treatment. Reassessment of our results in larger studies is required to draw firm conclusions for clinical practice. LEVEL OF EVIDENCE: Level V.

Association between full breastfeeding, timing of complementary food introduction, and iron status in infancy in Germany: results of a secondary analysis of a randomized trial.

PURPOSE: Considering the low content in breast milk breastfed infants might be at particular risk for depleted iron stores after the first months of life. This study evaluates the association of the mode of milk feeding and the timing of complementary food (CF) introduction with parameters of iron status in term healthy infants in Germany. METHODS: In this secondary analysis of a randomized controlled trial, parents recorded all foods consumed by their infants from the age of 8 weeks onwards. Mothers were advised on the German food-based dietary guidelines for infants. Accordingly, CF was introduced between the fifth and seventh month of age. Blood samples were taken at 4 and at 10 months of age for analyses of iron status parameters. Iron depletion was defined as serum ferritin <12 ng/mL. RESULTS: The iron intake was lower in breastfed infants (n = 50) than in formula fed (n = 23) with decreasing differences during the course of infancy. At 10 months of age, most iron parameters were not associated with the mode of milk feeding or the timing of CF introduction. At this age, the iron depletion prevalence was >34% without general differences according to the mode of milk feeding or the timing of CF introduction. CONCLUSION: The high prevalence of depleted iron stores observed in both breastfed and formula-fed infants illustrates the need for further studies to improve our understanding of the optimal iron intake and sensitive parameters of iron status in infancy.

High protein intake along with paternal part-time employment is associated with higher body fat mass among girls from South China.

PURPOSE: Protein intake has been suggested to be associated with body composition among western children. Our aim was to determine whether protein intake is associated with body composition among Chinese children and to investigate whether parental socioeconomic status modifies these associations. METHODS: Cross-sectional data were collected from the baseline survey of an ongoing population-based prospective open cohort study conducted in 2013. In this survey, 2039 children in South China were recruited using cluster random sampling. Information of 1704 children (47% girls), aged 7-12 years from three primary schools (42 classes), on diet and anthropometry was included finally. Their daily protein intake was obtained by 3-day 24-h dietary recalls. Skinfold thickness, body height, and weight were measured to calculate percent body fat (%BF), fat mass index (FMI), and fat-free mass index (FFMI). Parental characteristics were collected by questionnaires. RESULTS: Among girls, protein intake was positively associated with %BF and FMI [estimate (SE) for %BF: 0.007 (0.003), p = 0.04; for FMI: 0.092 (0.002), p = 0.03], adjusted for pubertal stage, breast-feeding, maternal overweight, carbohydrate intake, energy intake, and physical activity level. Furthermore, there was interaction between paternal occupation and the relations of dietary protein with %BF and FMI (p for interaction ≤ 0.04). None of the associations between protein intake and %BF, FMI, or FFMI was found among boys. CONCLUSIONS: Our data indicate that school-aged girls, but not boys, living in South China with higher dietary protein intake might have higher body fat mass, which could be modified by paternal occupation.

Effect of an vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients - a randomized controlled trial: study protocol.

BACKGROUND: Depression is a significant health and economic burden worldwide affecting not only adults but also children and adolescents. Current treatment options for this group are scarce and show moderate effect sizes. There is emerging evidence that dietary patterns and specific nutritional components might play a role in the risk for developing depression. This study protocol focusses on the role of vitamin D which is for long known to be relevant for calcium and phosphorous homeostasis and bone health but might also impact on mental health. However, the assessment of the vitamin D status of depressed juvenile patients, or supplementation of vitamin D is currently not part of routine treatment. Controlled intervention studies are indispensable to prove whether a vitamin D deficiency ameliorates depressive symptoms. METHODS/DESIGN: This double blinded, randomized controlled trial will enroll 200 inpatients from a child and adolescent psychiatric department with a vitamin D deficiency defined by a 25(OH)-vitamin D-level < 30 nmol/l (12 ng/ml) and a Beck Depressions Inventory (BDI-II) score > 13 (indicating at least: mild depression). Upon referral, all patients will be screened, checked for inclusion criteria, and those eligible will be randomized after written consent into a supplementation or placebo group. Both study-arms will receive treatment-as-usual for their psychiatric disorder according to established clinical guidelines. The participants of the vitamin D supplementation group will receive 2640 I.E. vitamin D3 q.d. for 28 days in accordance with best practice in pediatric endocrinology. We hypothesize that delaying supplementation of vitamin D in the placebo arm will affect the treatment success of the depressive symptomatology in comparison to the vitamin D supplementation group. Patients will be enrolled for a period of 28 days based on the mean length of hospitalization of juveniles with depression. DISCUSSION: Randomized controlled trials in children and adolescents with depression are needed to elucidate the role of a vitamin D deficiency for mental disorders and to investigate the relevance of a routine assessment and supplementation of vitamin D deficits. TRIAL REGISTRATION: DRKS00009758, 16/06/2016 (retrospectively registered).

Vitamin D and mental health in children and adolescents.

While vitamin D is known to be relevant for bone health, evidence has recently accumulated for an impact on mental health. To identify the potential benefits and limitations of vitamin D for mental health, an understanding of the physiology of vitamin D, the cut-off values for vitamin D deficiency and the current status of therapeutic trials is paramount. Results of a systematic PUBMED search highlight the association of vitamin D levels and mental health conditions. Here, we focus on children and adolescents studies as well as randomized controlled trials on depression in adults. 41 child and adolescent studies were identified including only 1 randomized controlled and 7 non-controlled supplementation trials. Overall, results from 25 cross-sectional studies as well as from 8 longitudinal studies suggest a role of vitamin D in the pathogenesis of mental disorders in childhood and adolescence. Findings from supplementation trials seem to support this hypothesis. However, randomized controlled trials in adults revealed conflicting results. Randomized controlled trials in childhood and adolescents are urgently needed to support the potential of vitamin D as a complementary therapeutic option in mental disorders. Study designs should consider methodological challenges, e.g., hypovitaminosis D at baseline, appropriate supplementation doses, sufficient intervention periods, an adequate power, clinically validated diagnostic instruments, and homogenous, well-defined risk groups.

Lunch at school and children's cognitive functioning in the early afternoon: results from the Cognition Intervention Study Dortmund Continued (CoCo).

Studies about effects of school lunch on children's cognition are rare; two previous studies (CogniDo, CogniDo PLUS) generally found no negative effects of lunch on children's cognitive performance at the end of lunch break (i.e. 45 min after finishing lunch), but suggested potential beneficial effects for single parameters. Therefore, the present study investigated the hypothesis of potential positive effects of school lunch on cognitive performance at early afternoon (90 min after finishing lunch). A randomised, cross-over intervention trial was conducted at a comprehensive school with fifth and sixth grade students. Participants were randomised into two groups: On day 1, group 1 did not eat lunch, whereas group 2 received lunch ad libitum. On day 2 (1 week later), group 2 did not eat lunch and group 1 received lunch ad libitum. The cognitive parameters task switching, working memory updating and alertness were tested using a computerised test battery 90 min after finishing the meal. Of the 204 recruited children, fifty were excluded because of deviations from the study protocol or absence on one of the 2 test days, which resulted in 154 participants. Data showed no significant effects of lunch on task switching, working memory updating and alertness (P values between 0·07 and 0·79). The present study suggests that school lunch does not seem to have beneficial effects on children's cognitive functions regarding the conducted tests at early afternoon. Together with our previous studies, we conclude that school lunch in general has no negative effects on cognitive performance in children. However, beneficial effects seem to be restricted to a relatively short time period after eating lunch.