Background: Prediabetes is an intermediate state of increased glucose concentrations above the normal range but below the diagnostic threshold for type 2 diabetes (T2D). Adults with overweight and prediabetes are at increased risk of progression to T2D and metabolic imbalance. Feiolix -a whole-fruit feijoa powder rich in abscisic acid, polyphenols and dietary fibre which may support metabolic health with complementary pathways. Objective: To evaluate the effects of low and high-dose Feiolix compared with placebo, on HbA1C, glucagon like peptide (GLP-1) and other metabolic parameters. Methods: Adults aged 21-65 years with prediabetes i.e. glycosylated hemoglobulin (HbA1c) 5.7-6.4% and overweight with body mass index (BMI)- 25.0-29.9 kg/m2 were randomised to receive Feiolix-LD (300 mg/day) or Feiolix-HD (1,150 mg/day), or placebo (maltodextrin) for 12 weeks. Anthropometric measurements were obtained monthly, and fasting blood samples were collected at baseline and 12 weeks post intervention. Postprandial blood samples were collected at baseline and 12 weeks. Outcomes included HbA1c, GLP-1, fasting plasma glucose, insulin resistance lipid markers, body weight and BMI. Analyses were conducted using ANCOVA model with baseline values as covariates. Result: Of 41 individuals screened, 39 were randomised (13 per group); one participant withdrew from the Feiolix-LD. At week 12, HbA1c decreased by 0.5% in the Feiolix-HD and by 0.4% in the Feiolix-LD, with both reductions significantly greater than placebo (p < 0.05); Compared with placebo, Feiolix supplementation significantly lowered fasting glucose, insulin, HOMA-IR, total cholesterol and LDL-cholesterol. The Feiolix-HD significantly attenuated the increase in triglycerides observed in the placebo group and was associated with significant reductions in body weight and BMI versus placebo by month 2. However, no change in GLP-1 was observed between the treatments. No treatment-related adverse events were reported. Conclusion: This study supports the potential of Feiolix supplementation to improve metabolic health, including glycemic and lipid outcomes, with additional benefits for body weight and BMI at the higher dose. This study supports the potential of Feiolix supplementation to improve metabolic health, including glycemic and lipid outcomes, with additional benefits for body weight and BMI at the higher dose