Effects of Zinc Supplementation on the Anthropometric Measurements, Leptin, Ghrelin and C-reactive protein in the Obese Adults with Increased Appetite and Baseline Zinc Deficiency: A Randomized Controlled Trial

Appetite is one of the main obesity-controlling factors that can be influenced by hormones, including leptin and ghrelin. This study aimed to determine the effects of zinc supplementation on the serum levels of leptin, ghrelin, C-reactive protein (CRP), and anthropometrical indices in obese individuals with increased appetite and zinc deficiency.

This study was conducted among 50 individuals with body mass index > 30 kg/m2 in Shiraz, Iran in 2018. The participants were randomly allocated to the intervention that consumed one capsule containing 30 mg/day zinc (ZG) and placebo group (PG) for 3 months. Moreover, all participants were prescribed calorie-restricted diet, 500 kcal/d less than their weight maintenance requirement energy. Anthropometric indices, dietary intake, serum zinc leptin, ghrelin, and CRP were measured at the baseline and after the intervention.

The ccomparison of mean changes in weight (-4.56 ± 2.47, P < 0.0001), body mass index (-1.65 ± 0.85, P < 0.0001), waist circumference (-5.54 ± 4.06, P < 0.0001), hip circumference (-3.19 ±1.91, P < 0.0001), and serum zinc (15.91 ± 5.24, P < 0.0001) showed a significant difference between groups with greater reduction in the zinc group. However, waist to hip ratio, ghrelin, and CRP showed no significant differences. A significant difference was revealed between groups in terms of the mean leptin concentration changes, in favor of the increase in leptin concentration in ZG (P = 0.003).

Based on the findings, three months of zinc supplementation improved some anthropometric and biochemical measures. Further studies are needed to confirm these results.