Background and Objective: Chocolate is one of the most popular food products, which, despite its desirable nutritional and health effects, can cause health risks/problems in consumers due to its high energy content. One way to reduce these risks/problems is to replace the sucrose with low-energy prebiotic compounds. The objective of the present study wasto explore the possibility of replacing sucrose with inulin, polydextrose, and maltodextrin in producing a low-energy dark chocolate with prebiotic properties using a Simplex Lattice Mixture Design.Materials and Methods: Sucralose (an artificial sweetener substituted for sucrose), was used along with inulin (a prebiotic), polydextrose and maltodextrin (bulking agents) with different ratios (0, 25, 50, 75 and 100%) to produce samples of a dark chocolate. The physicochemical (pH, water activity, and moisture, fat, and protein contents), mechanical and rheological (hardness, viscosity and yield value), as well as sensory (sweetness, firmness, mouth coating, and color) properties of the samples were examined.Results: The results showed that chocolate samples containing high levels of sugar substitutes had the highest moisture content and viscosity, as well as lower hardness. Out of the 5 mathematical models tested to predict the rheological characteristics of the chocolates produced, the Casson model was found to be the most suitable. There were no statistically significant differences between the treated and control samples as regards sensory characteristics. Furthermore, the results of superimposed contour plot showed optimum ranges to be 0-6% and 11–15% for inulin, 22–38% and 64–79% for polydextrose and 21–31% and 62-77% for maltodextrin.Conclusion: The findings show that a low-energy dark chocolate with prebiotic functional food properties can be produced using a low-energy sweetener (substituted for sucrose) and bulking agents (to improve rheological and sensory properties). Such a chocolate can compete with ordinary dark chocolate and can be consumed by children, adults and dieters with little restriction.