BACKGROUND: Our previous work has shown that oral supplementation with inulin propionate ester (IPE) reduces intra-abdominal fat and prevents weight gain and that oral propionate intake enhances resting fat oxidation. The effects of IPE combined with exercise training on energy substrate utilisation are unknown. The aim of this study was to investigate the impact of 4-weeks IPE supplementation, in combination with a moderate intensity exercise training programme, on whole body fat oxidation and on plasma GLP-1 and PYY. METHODS: Twenty overweight healthy women participated in randomised parallel study and underwent 4 weeks of supervised exercise training either with IPE (EX/IPE group) or Placebo (EX/Placebo group) supplementation. Before and after the intervention participants conducted an experimental trial, which involved collection of expired gas and blood samples in the fasted state and during 7 h of the postprandial state. RESULTS: Within groups, the EX/IPE group significantly enhanced the amount of fat (Pre, 24.1 ± 1.2 g; Post, 35.9 ± 4.0 g, P < 0.05) oxidised and reduced CHO (Pre, 77.8 ± 6.0 g; Post, 57.8 ± 7.7 g, P < 0.05) oxidised, reduced body weight (Pre, 77.3 ± 4.2 kg; Post, 76.6 ± 4.1 kg, P < 0.05) and body fat mass (Pre, 37.7 ± 1.9%; Post, 36.9 ± 1.9%, P < 0.05). In EX/Placebo group, changes in amount of fat (Pre, 36.8 ± 3.9 g; Post, 37.0 ± 4.0 g) and CHO (Pre, 62.7 ± 6.5 g; Post, 61.5 ± 7.4 g) oxidised, body weight (Pre, 84.2 ± 4.3 kg; Post, 83.6 ± 4.3 kg) and body fat mass (Pre, 40.1 ± 1.9%; Post, 38.7 ± 1.5%) were not significant (P > 0.05). Comparing between groups, changes in the amount of fat oxidised were significantly (P < 0.05) different and a trend for difference was observed for amount of CHO oxidised (P = 0.06) and RER (P = 0.06). The interventions had no impact on fasting or postprandial plasma concentrations of GLP-1 and PYY. CONCLUSION: Moderate intensity exercise training programmes when combined with daily oral IPE supplementation may help overweight women to achieve increase in fat oxidation. The study was registered at clinicaltrials.gov as NCT04016350.