Background Consuming a bedtime snack is often recommended for people with type 2 diabetes. Objective This systematic review aims to evaluate the evidence from intervention studies to determine whether consuming a bedtime snack improves fasting hyperglycemia and/or overall glycemic control in individuals with type 2 diabetes. Methods: PubMed, Medline (EBSCO), Cochrane Library and CINAHL Plus (EBSCO) databases were searched until July 20 2022. We included prospective studies in people with type 2 diabetes or prediabetes that included the intervention of a bedtime snack, consumed > 30 minutes after dinner and < 2 hours before bed and reported glycemic outcomes. Results The systematic review included 16 studies. There was no consistent relationship between consumption of a bedtime snack and improved glycemic control, especially when a no snack control was included. Of the four studies that included the use of corn starch, a low dose seemed to have benefits over high dose corn starch in terms of improved nocturnal and fasting glucose levels. Conclusions Current advice to consume a bedtime snack is based on a limited number of intervention studies that often do not include a no snack control, nor have used a feasible bedtime snack option that could be translated into every day clinical practice. Further research is needed in type 2 diabetes patients treated with or without insulin. PROSPERO Registration Number: CRD42020182523

The incidence of gestational diabetes mellitus (GDM) is increasing. One in three women require insulin to achieve glycaemic targets in GDM. However, it is unclear whether insulin therapy alone is the most effective treatment for all women in achieving glycaemic control and preventing adverse pregnancy outcomes. Although no oral hypoglycaemic agents are approved for pregnancy in Australia, recent research indicates that metformin is effective in preventing adverse perinatal outcomes and may even have possible benefits in the long term. Furthermore, there appears to be a specific role for both metformin and insulin among the GDM population. Metformin provides an option to offer an individualised approach to treat GDM.