Relevance to current evidence
Until now, there has been no robust evidence to provide guidance on the primary prevention
of GDM due to the small number of studies limited to few interventions in published reviews.
[38] The number of eligible studies has doubled since our previous review that evaluated the effect
of mixed approach (diet and lifestyle modification) on GDM. [11] By evaluating all the relevant
interventions, our review is the first to systematically assess the effects of nutritional
manipulation in pregnancy on GDM. We complied with current guidelines and used a comprehensive
search strategy without any language restrictions. By including only randomised trials,
we avoided some of the pitfalls encountered by earlier reviews that included quasirandomised
studies [10] and women with GDM [9].