Authors’ reply to Gachi, Mullie and colleagues, and Weatherburn

We appreciate the interest in our recent article on pre-pregnancy potato consumption and risk of gestational diabetes mellitus (GDM).1 Below we provide responses to a few major points raised by readers Pre-pregnancy consumption of potato in our study did not include sweet potato.2 Sweet potato consumption in our study population was too low (~95% consumed <1 serving a week) for us to reliably evaluate its association with the risk of GDM. The role of pre-pregnancy sweet potato consumption in the development of GDM warrants further investigation. We are aware that sweet potato—which is rich in complex carbohydrates, dietary fibre, β carotene, vitamin C, vitamin B6, anthocyanin, and minerals—is considered to be a nutritious vegetable.3 Studies in animal models indicated that sweet potatoes have hypoglycaemic effects through ameliorating oxidative stress and inflammation and improving pancreatic β cells mass.4 In humans, sweet potato has been used in traditional medicine for the treatment of type 2 diabetes. However, data from randomised controlled trials and large observational studied on the efficacy of sweet potato in glycaemic control in humans are insufficient and inconclusive.3 Our study was not designed to look at the underlying mechanisms of the observed positive association between pre-pregnancy potato intake and GDM risk; future studies will elucidate these.5 Evidence suggests that the potato’s high glycaemic index …