Processed meat intake and incidence of colorectal cancer: a systematic review and meta-analysis of prospective observational studies.

The objective was to use accumulated evidence to explore the association between processed meat intake and risk of colorectal cancer (CRC) and to investigate the reliability of associations by evaluating patterns of risk by study population characteristics and research quality parameters. We included 29 observational prospective cohort studies with relative risk estimates and 95% confidence intervals for CRC according to various levels of processed meat consumption. Risk of bias was assessed using Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I) tool. Data sources were PubMed and Embase up to January 2017. The summary relative risks for high versus low processed meat consumption and risk of CRC, colon, and rectal cancer were 1.13 (95% CI: 1.01, 1.26), 1.19 (95% CI: 1.09, 1.31), and 1.21 (95% CI: 0.98, 1.49), respectively. Similar estimates were observed for the dose-response analyses. Heterogeneity across studies was detected in most analytical models. The overall judgment showed that two out of 29 studies had a moderate risk of bias, 25 had a serious risk of bias, and 2 had a critical risk of bias. The bias domains most often rated critical were bias due to risk of confounding, bias due to missing data, and selective outcome reporting bias. Although this meta-analysis indicates a modest association between processed meat intake and an increased risk of CRC, our assessment of internal validity warrants a cautious interpretation of these results, as most of the included studies were judged to have serious or critical risks of bias.

Shorter sleep duration is associated with higher energy intake and an increase in BMI z-score in young children predisposed to overweight.

BACKGROUND: Inadequate sleep has been shown to be a contributor to obesity in both children and adults. Less evidence is available for toddlers and among those with higher obesity risk. The objective of this study was to examine the relationship between sleep patterns and body weight development in a group of young obesity-predisposed children, and to assess whether intakes of energy or macronutrients mediate this relationship. METHODS: Participants included 368 Danish children aged 2-6 years from the Healthy Start Study, a 1.3 year randomised controlled intervention trial. Sleep habits were measured using a 7-day sleep diary. Multivariate linear regression with adjustment for confounders was used to assess the association of sleep duration and sleep variability with 1.3 year changes (Δ) in body mass index (BMI) z-score from baseline to follow-up. RESULTS: The average nighttime sleep duration was 10.7 h (range 8.8-12.5 h). After controlling for potential confounders, a significant inverse association between nighttime sleep duration and ΔBMI z-score (ß=-0.090, P=0.046) was observed. This relationship was mediated by energy intake, with all macronutrients contributing to this mediation effect. No associations were found for sleep variability and ΔBMI z-score but baseline intake of added sugars and sugary beverages were positively associated with sleep variability. CONCLUSION: Shorter sleep duration, mediated by energy intake in early in life, seems a risk factor for weight gain among young obesity-predisposed children.