Reduced in sugar biscuits made with fructooligosaccharides (15.2%) and 0%, 8% and 17% of extruded brewers' spent grain (EBSG) were formulated as a healthy snack. The investigation aimed to study the impact of the formulation on technological parameters, sensory attributes and gastrointestinal effects. Biscuits’ hardness, color, water and oil holding capacity, starch gelatinization and microstructure were analyzed. Products were tested in a randomized blind cross-over design trial with 51 adults, determining sensory acceptance, satiety and gastrointestinal tolerance. Results showed an addition of 17% EBSG caused product hardening, darker color, and a more compact structure. These parameters were in line with consumers' product description and caused lower acceptability, while the acceptability of biscuits with 8% or 0% EBSG did not differ (p > 0.05). However, biscuits with 17% of EBSG were the only ones to exhibit a positive effect on short-term appetite control. Formulations showed good and similar gastrointestinal tolerance (p > 0.05).