Objective: The aim of the study is to investigate the effect of Jeju steamed onion (ONIRO) on body fat and metabolic profiles in overweight subjects. Methods: This randomized, double-blind, placebo-controlled clinical intervention was conducted and completed at one clinical research site. The subjects (n = 70) were randomly divided into placebo or test group and were instructed to take before each meal either the placebo or ONIRO capsule for 12 weeks. Anthropometric as well as serum and metabolic parameters, including triglycerides, cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, leptin, adiponectin, C-peptide, and aspartate aminotransferase (AST) were measured at baseline and after 12 weeks. Body composition was also measured by dual-energy x-ray absorptiometry (DEXA) and computed tomography (CT). This trial is registered under the trial registration code clinicaltrials.gov: NCT03645382 (https://register.clinicaltrials.gov). Results: Compared to the placebo, ONIRO supplementation for significantly reduced the percentage of body fat and fat mass as measured by DEXA (p = 0.028 and 0.022, respectively) with no significant effects on lean body mass. CT analyses at the L1 level showed a significant decrease in the areas of whole fat, visceral fat, and subcutaneous fat (p = 0.009, p = 0.039, p = 0.020, respectively), while CT scan of L4 resulted in a significant reduction of whole fat area and subcutaneous area (p = 0.006 and p = 0.012, respectively). The levels of triglycerides (TG) and C-peptide were significantly lower after 12 weeks of ONIRO treatment. Conclusions: These findings suggest that ONIRO supplementation reduces total body fat, notably abdominal visceral fat, with positive changes of the clinically relevant metabolic parameters serum TG and C-peptide.

The difference between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) phenotypes might be partly attributable to genetic traits modulating body fat distribution and other obesity-related metabolic traits, specifically with regard to LEPR rs8179183 in Korean women with obesity. A total of 177 females with obesity participated in the study and were grouped by genotype (GC or GG) and metabolic health status (MHO and MUO). Between the MHO and MUO groups, significant differences were found in waist circumference, waist-to-hip ratio, lipid profiles, glucose-related markers, biomarkers of liver health, adiponectin, oxidative stress markers, whole fat area (WFA), and subcutaneous fat area (SFA) at the level of the L1 vertebra, and WFA and visceral fat area (VFA) at the level of the L4 vertebra. Lipid profiles, glucose-related markers, adipokines, oxidative stress markers, and WFA and VFA at the L4 level were significantly different between the GC and GG genotypes. Notably, the individuals with the MUO phenotype and the GG genotype had the least favorable values of glucose-related markers, lipid profiles, adipokines, oxidative stress markers, and regional fat distribution. These observations suggest that the development of obesity-related metabolic traits is highly associated not only with the rs8179183 genotype but also with metabolic status in Korean females with obesity.