Obesity is one of the main causes of chronic inflammatory disorders and has an impact on the healthcare system by increasing healthcare costs. Replacing refined grains with whole grains like millets that are economical and available helps to reduce weight as well as improve the nutrient content of food. This study was conducted to investigate the positive effects of finger millet flour (FMF) as a replacement for wheat flour (WF) on obese rats fed a high-carbohydrate diet (HCD) as well as its effect on the sensory qualities of the resultant snack. The results revealed that the FMF is a good source of dietary fiber, B vitamins, particularly niacin (1.11 mg/100 g), minerals such as Ca, K, P, and Fe, as well as essential amino acids, mainly leucine, valine, and phenylalanine. The FMF also showed high levels of phenols (2624 mg GAE/g), flavonoids (2.37 mg CE/g), and phytic acid (6.05 mg/g), which represent high antioxidant activity against DPPH radicals. In comparison to HCD alone, HCD supplemented with FMF reduced body weight gain, feed efficiency ratio, and body mass index of obese rats and improved the serum lipid profile, particularly by reducing triglycerides, cholesterol, and LDL-c compared to HCD alone. Additionally, HCD supplemented with FMF controlled insulin, leptin, and cortisol hormones and improved serum antioxidant biomarkers by reducing malondialdehyde (MDA) and raising glutathione peroxidase (GPX). The healthy snacks were more fragile, crispy, and palatable when WF was substituted with FMF up to 70 and 100%.