The non-HDL-C:  HDL-C ratio was found to be an independent risk factor for diabetes.

Summary Objectives Low glycaemic index (GI) diets may aid in weight loss by reducing postprandial blood glucose excursions, leading to more stable blood glucose concentrations and therefore a reduction in hunger. To test this hypothesis, we conducted a systematic review and meta‐analysis of randomized controlled trials comparing low GI diets with other diet types. Methods We included 101 studies involving 109 study arms and 8,527 participants. We meta‐analysed the studies using a random‐effects model and conducted subgroup analyses and meta‐regression based on control diet, blood glucose control, baseline BMI and dietary GI. Results Low GI diets resulted in small but significant improvements in body weight, BMI, LDL and total cholesterol overall, although no individual control diet was significantly different from low GI diets. Studies in people with normal blood glucose who achieved a difference in GI of 20 points or more resulted in a larger reduction in body weight (SMD = −0.26; 95% CIs [−0.43, −0.09]), and total cholesterol (SMD = −0.24; 95% CIs [−0.42, −0.05]) than studies that only achieved a smaller reduction in GI. Conclusions Low GI diets, especially diets achieving a substantial decrease in GI, were moderately effective in lowering body weight. However, efforts should be made to increase compliance with low GI diets, in order for them to be effective in people with overweight and obesity.

Aim To assess the causality between alcohol intake, diabetes risk and related traits. Design Mendelian randomization (MR) study. Subgroup analysis, standard instrumental variable analysis and local average treatment effect (LATE) methods were applied to assess linear and non-linear causality. Setting China. Participants A total of 4536 participants, including 721 diabetes cases. Findings Carriage of an ALDH2 rs671 A allele reduced alcohol consumption by 44.63% [95% confidence interval (CI) = -49.44%, À39.37%]. In males, additional carriage of an A allele was significantly connected to decreased diabetes risk for the overall population [odds ratio (OR) = 0.716, 95% CI = 0.567-0.904, P = 0.005] or moderate drinkers (OR = 0.564, 95% CI = 0.355-0.894, P = 0.015). In instrumental variable (IV) analysis, increasing alcohol consumption by 1.7-fold was associated with an incidence-rate ratio of 1.32 (95% CI = 1.06-1.67, P = 0.014) for diabetes risk, and elevated alcohol intake was causally connected to natural log-transformed fasting, 2-hour post-load plasma glucose (β = 0.036, 95% CI = 0.018-0.054; β = 0.072, 95% CI = 0.035-0.108) and insulin resistance [homeostatic model assessment for IR (HOMA-IR] (β = 0.104, 95% CI = 0.039-0.169), but was not associated with beta-cell function (HOMA-beta). In addition, the LATE method did not identify significant U-shaped causality between alcohol consumption and diabetes-related traits. In females, the effects of alcohol intake on all the outcomes were non-significant.Conclusion Among men in China, higher alcohol intake appears to be causally associated with increased diabetes risk and worsened related traits, even for moderate drinkers. This study found no significant U-shaped causality between alcohol consumption and diabetes-related traits. M.P. and J.Z. contributed equally to this study.