TABLE 2.

Meta-analysis showing the effect of zinc supplementation on body weight (in kilograms) based on several subgroups¹

		Meta-analysis			Heterogeneity
Study group	Studies, n	Participants, n	WMD (95% CI), kg	P-effect	Q statistic	P-within group	I 2 (%)	P-between group
Overall	19	967	0.04 (−0.36, 0.45)	0.83	110.04	<0.001	83.6	—
Sex								0.001
Male	1	18	−1.40 (−3.26, 0.46)	0.14	0.00	—	—
Female	7	355	0.09 (−0.50, 0.69)	0.74	67.45	<0.001	91.1
Both	11	594	0.07 (−0.51, 0.66)	0.80	29.43	0.001	66.0
Type of zinc supplement								<0.001
Sulfate	11	530	0.31 (−0.18, 0.81)	0.21	68.89	<0.001	85.5
Gluconate	7	381	−0.40 (−0.96, 0.15)	0.15	11.21	0.08	46.5
Aminochelate	1	56	0.00 (−0.76, 0.76)	1.00	0.00	—	—
Zinc supplemented, mg/d								<0.001
<40	9	416	0.27 (−0.27, 0.81)	0.32	64.20	<0.001	87.5
≥40	10	551	−0.19 (−0.67, 0.29)	0.44	18.32	0.03	50.9
Baseline BMI, kg/m2								0.63
Nonoverweight ( ≤24.9)	7	334	0.57 (−0.13, 1.28)	0.11	10.27	0.11	41.6
Overweight and obese (≥25)	12	633	−0.14 (−0.63, 0.35)	0.58	99.54	<0.001	88.9
Study duration, wk								<0.001
Short period (≤8)	13	692	0.16 (−0.31, 0.64)	0.50	85.72	<0.001	86.0
Long period (>8)	6	275	−0.22 (−0.84, 0.40)	0.49	10.04	0.07	50.2
Health status of subjects								<0.001
Healthy overweight/obese	5	245	−0.55 (−1.06, −0.04)	0.03	5.84	0.21	31.5
Insulin resistance–related disorders2	6	312	−0.09 (−0.33, 0.14)	0.42	4.48	0.48	0.0
Hemodialysis	3	154	1.02 (0.38, 1.65)	0.002	2.26	0.32	11.4
Ischemic strokes	1	26	0.60 (−0.78, 1.98)	0.39	0.00	—	—
Depression	1	38	−1.50 (−2.93, −0.07)	0.04	0.00	—	—
Osteoporosis	1	60	0.90 (0.77, 1.02)	<0.001	0.00	—	—
Anorexia nervosa	1	35	1.00 (−0.60, 2.60)	0.22	0.00	—	—
Head and neck cancers	1	97	−0.91 (−3.21, 1.40)	0.43	0.00	—	—

¹All analyses were conducted using a random-effects model. WMD, weighted mean difference.

²Including polycystic ovarian syndrome, type 2 diabetes mellitus, and prediabetes.