Evaluation of the effect of oral taurine supplementation on fasting levels of fibroblast growth factors, β-Klotho co-receptor, some biochemical indices and body composition in obese women on a weight-loss diet: a study protocol for a double-blind, randomized controlled trial

BACKGROUND: Taurine (Tau) is involved in many biochemical functions such as regulation of glucose and lipid metabolism, enhancement of energy expenditure, anti-inflammatory effects and appetite control. The most important effect of Tau in obesity is its direct effect on adipose tissue. Some evidence has shown an impaired FGF (fibroblast growth factor) 19 and 21 biosyntheses in obesity. Besides the effects of eicosapentaenoic acid on serum FGF concentrations, the effect of other nutrients on FGFs is not clear. Since obesity as an important health problem is rising around the world and on the other side, Tau biosynthesis is reduced by adipose-tissue-derived factors in obesity, the effects of Tau and a weight-loss diet on obesity need to be investigated further. METHODS: We will conduct an 8-week. double-blind, parallel-group, randomized controlled clinical trial to investigate the effect of Tau supplementation on fasting serum levels of FGFs, β-Klotho co-receptor, some biochemical indices and body composition in 50 obese women aged between 18 and 49 years on a weight-loss diet. DISCUSSION: We will determine the other advantages of a weight-loss diet on new metabolic risk factors. Since Tau may regulate adipose-tissue-derived factors and a weight-loss diet can promote the useful effects of Tau supplementation; for the first time, the effects of a weight-loss diet along with Tau supplementation on these variables will be assessed. TRIAL REGISTRATION: Iran Clinical Trials Registry, ID: IRCT20131125015542N2. Registered on 24 November 2018. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-019-3421-5) contains supplementary material, which is available to authorized users.