Effects of zinc supplementation on obesity: study protocol for a randomized controlled clinical trial

Abstract

BackgroundThe prevalence of obesity is escalating alarmingly worldwide, and it is now becoming a rapidly growing epidemic in developing countries. Recent studies have reported that zinc has been implicated in altered lipid markers, insulin resistance and some obesity markers. There is a lack of evidence on zinc as a potential therapeutic agent to reduce weight and improve metabolic parameters in obese adults. The present study is designed to evaluate the effects of zinc supplementation on obese adults in Sri Lanka. Furthermore, we aim to evaluate the effects of zinc supplementation on metabolic parameters in this population.Methods/designThis study will be conducted as a randomized, double-blind, placebo-controlled clinical trial for a period of 3 months at the clinical laboratory, Department of Applied Nutrition, Wayamba University of Sri Lanka to assess the efficacy of daily zinc 20 mg supplementation in obese subjects. There will be a total of 80 subjects, aged between 18–60 years, of both genders, who are obese (body mass index (BMI) ≥25). Subjects will be stratified according to age, gender and BMI and randomly assigned into the test and placebo groups in a 1:1 ratio. The treatment drug is a capsule containing elemental zinc 20 mg as the active ingredient (as zinc sulphate). The placebo capsule will contain lactose monohydrate. The subjects will receive either zinc capsules or placebo daily for 3 months. The study treatments will be double blinded to both investigator and subject. The visits and the evaluations will be as follows: screening (visit 0), baseline (visit 1) and 3 month (visit 2). The primary outcome will be weight reduction among the obese subjects. Secondary outcome measures include glycaemic status (fasting blood glucose), lipid parameters (total cholesterol, triglyceride levels, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol) and blood pressure.DiscussionThe trial protocol will aim to establish the effects of zinc supplementation on weight reduction and metabolic risk parameters among obese subjects.Trial registrationSri Lanka Clinical Trials Registry: SLCTR/2014/020. Registered on 18 September 2014.

The Mechanism of Zinc Sulfate in Improving Fertility in Obese Rats Analyzed by Sperm Proteomic Analysis

“…Zinc supplementation can reduce the weight of obese people. Blood glucose status (fasting blood glucose), blood lipid parameters (total cholesterol, triglyceride level, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol), and blood pressure are improved after zinc supplementation [7]. Oral zinc preparation can improve the content of zinc in seminal plasma, promote the transformation of sperm nuclear protein (i.e., from lysine to arginine), and inhibit the premature depolymerization of the sperm nucleus.…”

Effect of Zinc Supplementation on Insulin Resistance, Lipid Profile, BMI in Type II Diabetic Patients

“…The reduction in weight and BMI in our trial was only in zinc group post supplementation, but No statistical significant difference was found in BMI in comparison to control group and this result was in agreement with a clinical trial that conducted on 40 subjects after 6 weeks of 660 mg zinc sulphate supplementation [24] . Parallel to our results, in a systematic review and dose response meta-analysis, 27 trials (n=1438 participants) were included [27] , while a clinical trial conducted on 80 obese person concluded significant BMI reduction [28] . Larger sample size, longer duration in this trial may result in this diversity from our study.…”