Continuous and Discontinuous Adherence to the Sticky Japanese Diet on Adiponectin and Leptin Regulation

Background: In order to evaluate the regulational role of adiponectin and leptin on obesity, we examined the significance of daily adherence to the Sticky Japanese Diet (SJD) on the preventions of obesity and metabolic syndrome by assessing the fat adiponectin/leptin and plasma leptin levels using normal and high-fat diet (HFD) mice. Methods: Five-week-old male ICR strain mice were placed in individual cages and randomly divided into eight groups based on feeding of SJD or not. At the end of each treatment period, plasma triglyceride, cholesterol, and leptin levels were measured by biochemical analysis. The adiponectin and leptin levels in adipose tissue were measured using RT-PCR. Results: In normal mice, an eight-week treatment of SJD increased adiponectin levels in adipose tissue. However, four weeks after discontinuing the SJD, these levels decreased. Furthermore, continuous feeding of the SJD for eight weeks increased plasma leptin levels but not that of adipose tissue. And then, discontinuing the SJD for more than eight days resulted in a decrease in plasma leptin levels. In HFD mice, an increase in body weight and visceral fat was seen at eight days after discontinuing the SJD which was undertaken for a total of eight weeks. At this time, the plasma leptin levels in these mice were substantially higher than in normal mice, although these levels were getting to be decreased over four weeks. Conclusion: This study revealed that discontinuous adherence to the SJD induced decreases in both adiponectin and leptin levels. Together with our previous publication, this paper suggests that daily adherence to the SJD might be essential for maintaining good health. Keywords: NuruNeba (Sticky Japanese Diet); Washoku (Japanese foods); normal diet; high-fat diet; leptin; adiponectin; obesity; mice Abbreviations: SJD: Sticky Japanese Diet; HFD: High-Fat Diet; CE-2: CLEA Rodent Diet CE-2; TG: Triglyceride; UCP1: Uncoupling Protein-1; BAT: Brown Adipose Tissue