Metabolic disorders have become a major and growing global health problem, so finding potentially novel solutions with fewer harm is favourable to solving this problem. Thus, this research aimed to determine the effect of a diet supplemented with Curcuma longa rhizome powder on markers of oxidative stress as well as biochemical and haematological parameters of rats with diet-induced metabolic disorders. The powder was obtained from fresh Curcuma longa rhizome for preparation of extracts, which were used for in vitro analysis. After induction of metabolic disorders in male Wistar rats, they were separated into five groups: base, control, and high-fructose and high-fat diet supplemented with Curcuma longa rhizome powder at 2.5%, 5%, and 10%, respectively. The phytochemical analysis of the Curcuma longa rhizome powder extracts revealed the presence of phenols (96.97 ± 0.79 mg GAE/g) and flavonoids (133.19 ± 1.64 mg CE/g) and also showed good activities in DPPH free radical scavenging (79.46 ± 2.12%) and good inhibition of alpha-amylase enzyme (94.12 ± 2.84%). The food supplementation with Curcuma longa rhizome powder lowered Lee index (326.88 ± 3.08 to 262.45 ± 4.71), glycaemia (189.25 ± 5.98 to 120.5 ± 4.91 mg/dl), peritoneal fat deposition (2.18 ± 0.02 to 1.35 ± 0.14 g/100 g of body weight), triglycerides (58.35 ± 5.37 to 109.94 ± 1.42 mg/dl), total cholesterol (208.53 ± 1.53 to 114.18 ± 2.20 mg/dl), LDL-cholesterol (128.73 ± 3.64 to 17.55 ± 1.59 mg/dl), malondialdehyde (67.54 ± 2.48 to 39.75 ± 1.02 nmol/ml), and nitric oxide (27.83 ± 1.44 to 19.36 ± 1.28 nmol/ml) and increased HDL-cholesterol (48.12 ± 1.82 to 74.21 ± 1.04 mg/dl) and catalase activity (4.12 ± 0.56 to 11.58 ± 0.83 U/min/ml) with the best result at 5% supplementation. According to these results, the Curcuma longa rhizome powder supplement is a promising alternative for the treatment of metabolic disorders and oxidative stress.