Improving nutrition for the prevention of gestational diabetes: Current status and perspectives

Table 3 Summary of randomized trials on the effect of diet during pregnancy on the risk of gestational diabetes mellitus

Ref.	Design	Comparison	No. of participants (studies)	RR of GDM (95%CI)
Song et al[54], 2016	Meta-analysis, 27 RCTs (11487 women)	Lifestyle intervention of diet, PA or both vs standard management	11487 (27)	0.82 (0.70-0.95)
		PA plus diet vs standard management	6047 (14)	0.85 (0.70-1.03)
		Diet only vs standard management	1279 (5)	0.80 (0.58-1.10)
Tieu et al[53], 2017	Meta-analysis, 11 RCTs (2786 women)	Dietary recommendations vs standard treatment	1279 (5 RCTs)	0.60 (0.35-1.04); in overweight and obese women RR 0.39 (0.19-0.79)
		Low-glycemic index (GI) diet vs medium- or high-GI dietary recommendations	912 (4 RCTs)	0.91 (0.63-1.31)
		High-fiber diet vs standard dietary recommendations	25 (1)	No association
Shepherd et al[55], 2017	Meta-analysis, 23 RCTs (8918 women)	Combination of diet and exercise vs standard management	6633 (19)	0.85 (0.71-1.01)
Guo et al[56], 2019	Meta-analysis, 47 RCTs (15745 women)	Lifestyle intervention (diet, exercise, and mixed interventions) vs standard management	15745 (47)	0.77 (0.69-0.87)
		Diet alone vs standard management	2838 (11)	0.75 (0.60-0.95),

RR: Relative risk; PA: Physical activity; RCTs: Randomized clinical trials; CI: Confidence interval; GDM: Gestational diabetes mellitus.