Review of impacts of using body mass index as a screening tool in school children: A scoping review.

Body mass index (BMI) is used to screen for under- or overweight. However, it is unknown whether BMI-screening in school children reduces the incidence of overweight and obesity. We aimed to summarise the knowledge on positive and negative consequences on BMI and weight-related perceptions and behaviours of BMI-screening followed by an intervention to prevent and/or address obesity. We performed a systematic literature search, April 2023, using the PubMed, ScienceDirect and Google Scholar databases. We included randomised controlled trials and observational studies, including children aged 6 to 18 years and examining BMI-screening in a school setting. The primary outcome measures were BMI and weight status. Secondary outcome measures were weight-related perceptions and behaviours. Three studies met the inclusion criteria; two randomised controlled trials and one observational study. All studies used BMI-screening followed by sending report cards to the parents. None of the studies found a change in BMI z-scores in school children. Screening could cause transitory body-dissatisfaction and increase peer weight talk, yet potentially reduce problematic weight behaviours like skipping meals or excessive dieting. Reporting BMI to parents may influence their perception of their children's weight status, but does not change behaviour. The sparse evidence available suggested that BMI screening followed by sending report cards to parents does not change BMI z-scores among children in primary, middle and high school. Studies using appropriate evidence-based weight management interventions as a follow-up are lacking. Such studies may improve future prevention, detection and treatment of weight-related issues.

Childhood height, adult height, and the risk of prostate cancer.

PURPOSE: We previously showed that childhood height is positively associated with prostate cancer risk. It is, however, unknown whether childhood height exerts its effects independently of or through adult height. We investigated whether and to what extent childhood height has a direct effect on the risk of prostate cancer apart from adult height. METHODS: We included 5,871 men with height measured at ages 7 and 13 years in the Copenhagen School Health Records Register who also had adult (50-65 years) height measured in the Danish Diet, Cancer and Health study. Prostate cancer status was obtained through linkage to the Danish Cancer Registry. Direct and total effects of childhood height on prostate cancer risk were estimated from Cox regressions. RESULTS: From 1996 to 2012, 429 prostate cancers occurred. Child and adult heights were positively and significantly associated with prostate cancer risk. When adjusted for adult height, height at age 7 years was no longer significantly associated with the risk of prostate cancer. Height at 13 years was significantly and positively associated with prostate cancer risk even when adult height was adjusted for; per height z-score the hazard ratio was 1.15 [95% confidence interval (CI) 1.01-1.32]. CONCLUSIONS: The effect of height at 13 years on the risk of prostate cancer was not entirely mediated through adult height, suggesting that child height and adult height may be associated with prostate cancer through different pathways.