Comparison 1. Sweet potato (Caiapo) tablets versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Fasting blood glucose (final values)	3		Mean Difference (IV, Random, 95% CI)	Subtotals only
1.1 Sweet potato (2 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	0.0 [‐2.23, 2.23]
1.2 Sweet potato (4 g/day) at 6 weeks and below 3 months	2	73	Mean Difference (IV, Random, 95% CI)	‐0.65 [‐1.43, 0.13]
1.3 Sweet potato (4 g/day) at 3 to 5 months	2	122	Mean Difference (IV, Random, 95% CI)	‐0.68 [‐0.84, ‐0.52]
2 Postprandial blood glucose (final values)	1		Mean Difference (IV, Random, 95% CI)	Subtotals only
2.1 Sweet potato (4 g/day) at less than 3 months	1	61	Mean Difference (IV, Random, 95% CI)	‐0.98 [‐2.07, 0.11]
2.2 Sweet potato (4 g/day) at 3 months	1	61	Mean Difference (IV, Random, 95% CI)	‐1.01 [‐2.19, 0.17]
3 HbA1c (final values)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
3.1 Sweet potato (4 g/day) at 3 to 5 months	2	122	Mean Difference (IV, Random, 95% CI)	‐0.30 [‐0.57, ‐0.04]
4 Fasting plasma insulin (final values)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
4.1 Sweet potato tablets (2 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	0.30 [‐3.94, 4.54]
4.2 Sweet potato tablets (4 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	4.5 [‐0.93, 9.93]
4.3 Sweet potato tablets (4 g/day) at 5 months	1	61	Mean Difference (IV, Random, 95% CI)	1.11 [‐1.85, 4.07]
5 Body weight (final values)	1		Mean Difference (IV, Random, 95% CI)	Subtotals only
5.1 Sweet potato (4 g/day) at 3 months	1	61	Mean Difference (IV, Random, 95% CI)	‐1.0 [‐5.32, 3.32]
6 BMI (final values)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
6.1 Sweet potato (4 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	‐1.10 [‐4.43, 2.23]
6.2 Sweet potato (4 g/day) at 5 months	1	61	Mean Difference (IV, Random, 95% CI)	1.0 [‐0.81, 2.81]
7 Total cholesterol (final values)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
7.1 Sweet potato (4 g/day) at 3 to 5 months	2	122	Mean Difference (IV, Random, 95% CI)	‐0.47 [‐1.10, 0.16]
8 Triglycerides (final values)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
8.1 Sweet potato (4 g/day) at 3 to 5 months	2	122	Mean Difference (IV, Random, 95% CI)	‐0.03 [‐0.41, 0.35]
9 HDL‐cholesterol (final values)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
9.1 Sweet potato (2 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	‐0.26 [‐0.63, 0.11]
9.2 Sweet potato (4 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	‐0.31 [‐0.64, 0.02]
9.3 Sweet potato (4 g/day) at 5 months	1	61	Mean Difference (IV, Random, 95% CI)	‐0.14 [‐0.31, 0.03]
10 LDL‐cholesterol (final values)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
10.1 Sweet potato (2 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	0.02 [‐0.95, 0.99]
10.2 Sweet potato (4 g/day) at 6 weeks	1	12	Mean Difference (IV, Random, 95% CI)	‐1.06 [‐1.92, ‐0.20]
10.3 Sweet potato (4 g/day) at 5 months	1	61	Mean Difference (IV, Random, 95% CI)	‐0.13 [‐0.60, 0.34]