Effects of modified-Paleo and moderate-carbohydrate diets on body composition, serum levels of hepatokines and adipocytokines, and flow cytometric analysis of endothelial microparticles in adults with metabolic syndrome: a study protocol for a randomized clinical trial

BACKGROUND: Metabolic syndrome is a combination of metabolic risk factors causing a pathological condition that increases the risk of non-communicable diseases, such as diabetes and cardiovascular diseases. A variety of dietary approaches have been examined to halt this rapid trend; however, the effects of modified-Paleo diet and medium-carbohydrate diet on inflammation, adipokines, hepatokines, and the profile of endothelial microparticles in individuals with metabolic syndrome have not been investigated in detail. The present study is designed to examine the effect of modified-Paleo and moderate-carbohydrate diet with two delivery modes: “fixed diet plan” vs “calorie counting” on weight, body composition, serum levels of some hepatokines and adipocytokines, and flow cytometric analysis of endothelial microparticles in adults with metabolic syndrome. METHODS: Eighty metabolic syndrome patients will be recruited in this study. They will be randomly allocated to one of the following 4 groups: (1) receiving a modified-Paleo diet with calorie counting, (2) receiving a modified-Paleo diet with a fixed diet plan, (3) receiving a medium-carbohydrate diet with calorie counting, and (4) receiving a medium-carbohydrate diet with a fixed diet plan for 10 weeks. Weight, height, waist circumference, and body composition will be assessed at the study baseline and at the end of the trial. Serum insulin, asprosin, chemerin, FGF-21, CTRP-1, PYY, ghrelin, plasma EMPs (CD31+/CD42b− and CD144+/CD42b−), lipid profile, glycemic indices, hs-CRP, leptin, vitamin C, creatinine and satiety, hunger, fullness, and desire to eat (via visual analog scales) will be measured at the study baseline and at the end of the trial. Insulin resistance and insulin sensitivity will be determined using the HOMA-IR and QUICKI equations. DISCUSSION: To the best of our knowledge, this is the first randomized controlled trial that will determine the effect of modified-Paleo and moderate-carbohydrate diet on weight, body composition, serum levels of some hepatokines and adipocytokines, and the profile of EMPs in adults with metabolic syndrome. Moreover, the effects of different diet delivery modes, including “fixed diet plan” and “calorie counting” will also be analyzed. The results of this trial can provide clinical witnesses on the effectiveness of carbohydrate-restricted diets in ameliorating metabolic status and prevent the development of chronic diseases. TRIAL REGISTRATION: Iranian Registry of Clinical Trials IRCT2016121925267N4. Registered on 26 July 2017 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05612-y.