Introduction: School closures due to the COVID-19 pandemic affect children’s daily structure, mealtimes, physical activity, and sleeping habits, possibly exacerbating weight gain, particularly in vulnerable children with overweight and obesity. This study aimed to evaluate both perceived and objectively measured weight gain in children in the Netherlands during the COVID-19 pandemic and the effect of prior lifestyle intervention. Methods: A total of 150 children of the Children, Obesity and Lifestyle during COVID-19 (COLC) study (cohort A) reported perceptions of weight change during the COVID-19 pandemic. Anthropometric data of 65 children with overweight and obesity were collected at the expertise Centre for Overweight Adolescent and Children’s Healthcare in the same period (COACH; cohort B). Results: In cohort A, 43% of children with overweight and obesity perceived weight gain during the pandemic, compared to 15% of lean children. In cohort B, the BMI z-score increased significantly (+0.065 SD) within 5 months. Participation in a lifestyle intervention for >1 year and having parents with Dutch background was associated with less weight gain, specifically in children with obesity. Discussion/Conclusion: In particular, children with overweight and obesity seem to be at risk for accelerated weight gain during the COVID-19 pandemic. Prior long-term participation in a lifestyle intervention protects against this weight gain, which emphasizes the importance of strong support for vulnerable populations during health crises and pleads for wide implementation of lifestyle interventions for children.

Mycotoxins are toxic secondary metabolites produced by various fungi that can contaminate food crops, which, in turn, may lead to human exposure. Chronic exposure to mycotoxins can cause adverse health effects including reproductive and developmental toxicity. Pregnant women and their foetuses present a vulnerable group for exposure to mycotoxins that can cross the placenta. Human biomonitoring of mycotoxins provides a real-life approach to estimate internal exposure. In this pilot study, 24-h urine samples from 36 pregnant Dutch women were analysed for aflatoxin M1 (AFM1), total deoxynivalenol (DON), de-epoxy-deoxynivalenol (DOM-1), total zearalenone (ZEN), total α-zearalenol (α-ZEL), total β-zearalenol (β-ZEL) and total zearalanone (ZAN), where ‘total’ refers to mycotoxins and their conjugated forms. Serum samples from these women were analysed for fumonisin B1 (FB1) and ochratoxin A (OTA). All samples were measured using liquid chromatography–tandem mass spectrometry (LC-MS/MS). The most prevalent mycotoxins were total DON, total ZEN and OTA, with a detection frequency of 100%. DOM-1, total α-ZEL and total β-ZEL were detected but to a lesser extent, while AFM1, total ZAN and FB1 were undetected. Median concentrations were 4.75 μg total DON/L, 0.0350 μg DOM-1/L, 0.0413 μg total ZEN/L, 0.0379 μg total α-ZEL/L, 0.0189 μg total β-ZEL/L, and 0.121 μg OTA/L. The calculated median concentration for total ZEN and its metabolites was 0.105 μg/L. Based on two separate risk assessment approaches, total DON exposure in this group was considered to be of low concern. Similarly, exposure to total ZEN and its metabolites in this group was of low concern. For OTA, the risk of non-neoplastic effects was of low concern based on exposure in this group, and the risk of neoplastic effects was of low concern in the majority of participants in this group. The findings of this pilot study confirm the presence of mycotoxins in the urine and serum of pregnant Dutch women, with total DON, total ZEN, and OTA most frequently detected. Exposure to all measured mycotoxins was considered to be of low concern in this group, except for exposure to OTA, which was of low concern for the majority of participants. The study’s findings offer valuable insights but should be confirmed using a larger and more diverse sample of the Dutch general population.

Lifestyle interventions are the common treatment for children and adolescents with severe obesity. The efficacy of these interventions across age groups remain unknown. Therefore, this study aimed to compare the effectiveness of a lifestyle intervention on health parameters between children and adolescents with severe obesity. A longitudinal design was carried out at the Centre for Overweight Adolescent and Children’s Healthcare (COACH) between December 2010 and June 2020. Children (2–11 years old, n = 83) and adolescents (12–18 years old, n = 77) with severe obesity received a long-term, tailored, multidisciplinary lifestyle intervention. After 1 year, 24 children (28.9%) and 33 adolescents (42.9%) dropped out of the intervention. The primary outcome was the change in body mass index (BMI) z-score after one and two years of intervention. The decrease in BMI z-score over time was significantly higher in children compared to adolescents, the mean decrease was 0.15 (0.08–0.23) versus 0.03 (−0.05–0.11) after one year and 0.25 (0.15–0.35) versus 0.06 (−0.06–0.17) after two years of intervention; p values for the difference between children and adolescents were 0.035 and 0.012. After two years, multiple improvements in cardio metabolic health parameters were observed, especially in children. In conclusion, during our tailored lifestyle intervention, a positive and maintained effect on health parameters was observed in children with severe obesity. Compared to children, the effect on health parameters was less pronounced in adolescents.

Prior studies have shown that changes in daily structure and habits due to the COVID-19 pandemic affected the lifestyle and wellbeing of families. This study aimed to obtain in-depth information on children’s and adolescents’ experiences regarding their lifestyle and wellbeing during the pandemic. Semi-structured interviews with fifteen families were carried out between May and November 2021. Directed content analysis was used to analyze the transcripts and fundamental qualitative description to describe the results. Children and adolescents revealed an overall unhealthier lifestyle and decreased wellbeing. These negative effects were even larger in adolescents and children with overweight or psychosocial complaints. Our results revealed that parents were actively involved in maintaining a normal daily structure. Furthermore, diet changes were inconsistent and dependent on food availability. An increase in screen time was experienced as inevitable, and external influences were necessary to keep children and adolescents active. Almost no effects were reported on physical health, whereas negative emotions were experienced in varying degrees. Moreover, the decrease in social interactions was reported as the most negative effect of the pandemic. The above-mentioned insights may contribute to the development of preventive measures to promote a healthy lifestyle and wellbeing of children and adolescents during future pandemics.