Twelve studies were evaluated to investigate nutrition and physical activity interventions and the prevention of gestational diabetes.  Obesity, excessive weight gain prior to pregnancy and increased saturated fat intake are associated with the development of glucose abnormalities in pregnancy and increased risk of gestational diabetes.  Evidence regarding the consumption of micronutrients are conflicting, as the relationship between the prevalence of gestational diabetes and vitamin and mineral intake may be related to nutritional adequacy of the diet and gestational weight gain; further research is needed in this area.   

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.