Glucan, a recognized prebiotic primarily derived from fungi, bacteria, and plants, possesses significant nutritional value and biological activity. It serves as a thickener and emulsifier stabilizer, enhancing the texture and sensory properties of food. This study aimed to compare the inhibitory effects of glucans from yeast, oats, and bacteria on energy intake by characterizing their physicochemical properties and evaluating their impact on fat and glucose adsorption, starch and fat digestion in vitro, and glucose tolerance in vivo. The findings revealed that despite sharing similar active groups, the glucans exhibited distinct structures, viscosities, water solubilities, thermal degradation behaviors, and micromorphologies. All three sources demonstrated effectiveness in adsorbing fat and glucose, inhibiting starch and fat digestion, and improving glucose tolerance in mice, albeit with notable differences. Among these, Salecan glucan, derived from bacterial sources, exhibited superior performance in fat absorption, inhibition of starch and fat digestion, and enhancement of glucose tolerance. This is likely attributable to its higher viscosity, greater water solubility, and linear molecular structure. These results highlight the functional significance of glucans from different sources and underscore their potential application in developing functional foods aimed at managing energy intake.