Marine macroalgae are increasingly recognized as sources of bioactive compounds with potential benefits for metabolic health. This study investigated the chemical composition and metabolic effects of a 70% ethanol extract of the edible red algain a high-fat diet (HFD)-induced obesity model in rats. Chemical profiling using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) identified several classes of metabolites, including sterols, phenolic acids, flavonoids, and fatty acid derivatives such as palmitoleic acid, chlorogenic acid, gallic acid, and quercetin. Male Wistar rats were fed an HFD for 11 weeks to induce obesity and subsequently treated withextract (40-160 mg/kg body weight) for 28 days, with semaglutide (70 µg/kg) used as a pharmacological comparator. Supplementation with the extract significantly reduced obesity-related parameters compared with untreated HFD controls. The highest extract dose (160 mg/kg) decreased final body weight fromin HFD rats to, reduced visceral fat mass fromto, and lowered the adiposity index fromto. The extract also improved serum lipid profiles, reducing triglyceride levels fromin the HFD group to, while increasing HDL concentrations to. In addition, treatment increased adiponectin levels (to) and decreased leptin () and amylin () relative to obese controls. Histological analysis demonstrated a reduction in adipocyte hypertrophy. Gene expression analysis revealed downregulation of hypothalamicand adiposeand, together with upregulation of,, and. These findings suggest thatextract improves metabolic disturbances associated with diet-induced obesity through coordinated regulation of appetite signaling and lipid metabolism, supporting its potential development as a marine-derived functional food ingredient.