Effect of a walnut-based low carbohydrate diet on fat redistribution and visceral fat accumulation in people with central obesity: A randomized controlled trial.

BACKGROUND AND OBJECTIVES: The aim of this study was to determine whether a walnut-based low carbohydrate diet (w-LCD) promotes fat redistribution and reduces visceral fat accumulation in people with central obesity (CO). METHODS AND STUDY DESIGN: This study was a 12-week prospective randomized controlled trial. CO participants were recruited and assigned to the w-LCD group or high-carbohydrate, low-fat diet (HCD) group. According to "2021 Guidelines for Medical Nutrition Therapy of Overweight and Obesity", the HCD program was constructed; based on the HCD program, the w-LCD program was formed by replacing 150 grams/day of staple food with walnuts rich in healthy fat. The visceral fat area (VFA), trunk to leg fat ratio (TLR), and waist-to-hip ratio (WHR) were assessed at baseline and 12 weeks. RESULTS: The Group × Time interaction effects were significant for TLR (η² = 0.071, p = 0.039) and VFA (η² = 0.093, p = 0.014) with moderate effect, and body mass index (BMI, η² = 0.168, p = 0.001) with large effect. Although comparison be-tween groups revealed no significant on TLR, VFA and BMI at 12 weeks, comparison within groups showed all decreased with large effect on TLR (η² = 0.174, p = 0.001), VFA (η² = 0.393, p <0.001) and BMI (η² = 0.399, p <0.001) in the w-LCD group over time. CONCLUSIONS: A w-LCD achieves a significantly greater and faster fat reduction over time compared to the control group, providing a solid evidence-based foundation for dietary management in people with CO.