Abdominal Fat in Individuals with Overweight Reduced by Consumption of a 1975 Japanese Diet: A Randomized Controlled Trial

Objective: This study aimed to investigate whether the intake of the 1975 Japanese diet (JD) could reduce the amount of abdominal fat in people with overweight. Methods: Using a single-blind randomized controlled trial, the modern diet (MD) was compared with the 1975-type JD, which is based on the MD but includes five characteristics of the 1975 JD in an enhanced form. Overweight people were randomly assigned to an MD group (n = 30) and a JD group (n = 30). The participants consumed test diets that were provided three times a day for 28 days. Body composition measurements and blood biochemical examinations were performed before and after the test diet intake, and the proportions of change were compared. Results: Those in the JD group had significantly decreased BMI, fat mass, and levels of low-density lipoprotein cholesterol, glycated hemoglobin, and C-reactive protein (P = 0.002, 0.015, 0.014, 0.012, and 0.039, respectively) and significantly increased high-density lipoprotein cholesterol levels compared with those in the MD group (P = 0.020). Conclusions: The intake of a diet with the characteristics of the 1975 JD may have beneficial effects on lipid metabolism in people with overweight and reduce the onset risk of metabolism-related disorders, such as obesity and diabetes.