Zinc Supplementation and Body Weight: A Systematic Review and Dose–Response Meta-analysis of Randomized Controlled Trials

Abstract

The aim of this study was to determine the effect of zinc supplementation on anthropometric measures. In this systematic review and dose–response meta-analysis, we searched PubMed, Scopus, ISI Web of Science, and the Cochrane Library from database inception to August 2018 for relevant randomized controlled trials. Mean differences and SDs for each outcome were pooled using a random-effects model. Furthermore, a dose–response analysis for zinc dosage was performed using a fractional polynomial model. Quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Twenty-seven trials (n = 1438 participants) were included in the meta-analysis. There were no significant changes in anthropometric measures after zinc supplementation in the overall analysis. However, subgroup analyses revealed that zinc supplementation increased body weight in individuals undergoing hemodialysis (HD) [3 trials, n = 154 participants; weighted mean difference (WMD) = 1.02 kg; 95% CI: 0.38, 1.65 kg; P = 0.002; I2 = 11.4%] and decreased body weight in subjects who are overweight/obese but otherwise healthy (5 trials, n = 245 participants; WMD = −0.55 kg; 95% CI: −1.06, −0.04 kg; P = 0.03; I2 = 31.5%). Dose–response analyses revealed a significant nonlinear effect of supplementation dosage on BMI (P = 0.001). Our data suggest that zinc supplementation increases body weight in patients undergoing HD and decreases body weight in individuals who are overweight/obese but otherwise healthy, although after normalization for study duration, the association observed in subjects who are overweight/obese disappeared. Although more high-quality studies are needed to reach a definitive conclusion, our study supports the view that zinc may be associated with body weight.

Comparison of zinc acetate hydrate and polaprezinc for zinc deficiency in patients on maintenance hemodialysis: A single‐center, open‐label, prospective randomized study

“…We have to identify optimal candidates and duration of zinc supplementation for the renal anemia management. A recent meta‐analysis reported that zinc supplementation increased body weight and/or BMI in MHD patients . However, GNRI, which is nutritional indicator and comprises BMI, did not significantly change in this study.…”

“…A recent meta-analysis reported that zinc supplementation increased body weight and/or BMI in MHD patients. 23 However, GNRI, which is nutritional indicator and comprises BMI, did not significantly change in this study. Mechanisms and clinical implications of increasing BMI in zinc supplementation for MHD patients remain unclear.…”

Prevalence of Zinc Deficiency in Japanese Patients on Peritoneal Dialysis: Comparative Study in Patients on Hemodialysis

“…A cutoff BMI of 20 is recommended for diagnosis of protein energy wasting in Japanese patients on HD [38], suggesting that lower BMI is associated with mortality, especially in elderly patients on dialysis. It has also been reported that zinc supplementation might improve appetite, stimulate food intake, and increase BMI in patients on HD and that the serum leptin level is decreased in the HD population [39][40][41]. Furthermore, zinc supplementation was shown to increase the total cholesterol level and rate of protein catabolism in patients on HD [42,43].…”

Assessing the Effect of Zinc Supplementation on the Frequency of Migraine Attack, Duration, Severity, Lipid Profile and hs-CRP in Adult Women

“…Thus, in the IG, independent of the decrease in total energy intake, the significant increase of serum zinc levels led to a reduction of inflammation and consequently weight loss [ 41 ]. A meta-analysis showed no significant changes in anthropometric measures after zinc supplementation (ranged from 4 to 48 week, in different disease) in the overall analysis [ 42 ]. According to previous study, insufficient data about the effect of zinc supplementation on anthropometric indices in migraine patients has been reported [ 42 ], that needs to be evaluated in the future studies.…”

“…A meta-analysis showed no significant changes in anthropometric measures after zinc supplementation (ranged from 4 to 48 week, in different disease) in the overall analysis [ 42 ]. According to previous study, insufficient data about the effect of zinc supplementation on anthropometric indices in migraine patients has been reported [ 42 ], that needs to be evaluated in the future studies. Among possible mechanisms involved in weight loss following zinc supplementation can be mentioned the role of zinc in regulating appetite by altering the metabolism of hypothalamic neurotransmitters and increasing leptin secretion, inhibiting gene mutations leading to obesity, improving insulin sensitivity and reduction of inflammation [ 41 43 44 45 ].…”