Whey protein supplementation reducing fasting levels of anandamide and 2-AG without weight loss in pre-menopausal women with obesity on a weight-loss diet

Background: Despite the importance of dairy proteins in modifying of metabolic abnormalities, no attention has been given to their effects on endocannabinoids. Methods: A total number of 60 obese women were recruited in a 2-month randomized clinical trial. Following random allocation, they were assigned to one of the two groups: control (n = 30) and intervention (n = 30). Then, all the subjects followed a hypocaloric diet of 800 kcal below estimated energy needs. The intervention group received isocaloric weight-loss diet and whey protein powders (30 g/day). Baseline and 2-month fasting anthropometric, blood glucose, serum insulin, insulin resistance, lipid profile, AEA, and 2-AG were measured. Results: The study groups were homogenous in terms of baseline characteristics (p > 0.05) except for MUFA intake (p = 0.021). There were no significant differences in energy and macronutrient intakes in the intervention group compared to the control group at the end of the study (p > 0.05). The results of the ANCOVA did not show significant reductions in body weight and BMI of the intervention group compared to the control group (p > 0.05); however, WC, body fat, FBS, AEA, 2-AG, total cholesterol, and triglyceride decreased and HDL-c significantly increased in the intervention group compared to the control group (p < 0.05). Conclusions: In this study, the effects of simultaneous weight-loss diet and whey protein supplementation on the reduction of endocannabinoids were determined. Trial registration: Iranian Registry of Clinical Trials IRCT2017021410181N8. Registered on March 2017.