Konjac Glucomannan Improves Body Composition and Reduced Blood Cholesterol, Inflammation, and Cardiovascular Risk in Adults with Excess Weight: A Triple-Blind, Placebo-Controlled Randomized Clinical Trial

ABSTRACT Obesity and related cardiometabolic diseases pose significant global health challenges. Konjac glucomannan, a soluble dietary fiber, has shown promise in managing these conditions. However, rigorous studies are necessary to establish its benefits on human health. We designed a parallel-arm, triple-blind, placebo-controlled RCT to test the effects of glucomannan (3 g/day, 12 weeks) on body weight and composition, lipid profile, glucose metabolism, inflammation, adipokines, intestinal permeability, gut microbiota, and fecal metabolites in 40 adults. Participants were randomly assigned to either the glucomannan or placebo group, with both groups adhering to personalized hypocaloric diets and moderate physical activity. Outcomes were analyzed as intention-to-treat using linear mixed-effect models. Irrespective of the treatment, our intervention reduced body weight (mean: -2.39 kg; 95% CI: -3.38, -1.40), BMI (−0.83 kg/m 2 ; -1.15, -0.52), and waist (−2.70 cm; -3.87, -1.53). Glucomannan promoted additional benefits not obtained with the placebo, reducing body fat measured by DEXA (body fat%: -2.16%; -3.04, -1.28; VAT: -20.0 cm 2 ; - 29.2, -10.8; FMI: -0.98 kg/m 2 ; -1.34, -0.62), LDL (−14.1 mg/dL; -23.4, -4.9), and the atherogenic index (−0.50; -0.80, -0.21). It also diminished the Framingham score of 10-year risk of coronary heart disease (−0.370; -0.625, -0.115), C reactive protein (−1.01 mg/L; -2.18, 0.15), leptin (−2.06 ng/mL; -4.48, 0.365), and leptin/adiponectin (−0.282; -0.603, 0.040). The two treatments had similar intakes, physical activity, and adherence to the intervention. There were no adverse effects. This intervention fostered health benefits in a population at high risk of cardiometabolic diseases. Konjac glucomannan was an effective co-adjuvant for further reducing risk factors.