Nutritional characterization and postprandial glycemic response of low-calorie date snacks incorporating psyllium and oat fibers in healthy and type 2 diabetes

Background The global rise in type 2 diabetes (T2D) and obesity, driven by high-sugar snacks, underscores the need for low-calorie, fiber-enriched alternatives that attenuate postprandial glycemia while maintaining cultural appeal in date-consuming regions. Objectives This study nutritionally characterized low-calorie date-based snacks (LCDBSs) formulated with Sagai/Sukkari date paste (1:1), nuts, and oat or psyllium fibers at 5%, 7.5%, or 10% (OF1-3, PF1-3). Methods The formulated snacks were organolyptically and nutritionally evaluated as well as postprandial glycemic responses in 20 healthy adults (fasting glucose < 100 mg/dL, BMI average 23.39 kg m − 2 ) and 20 T2D patients (HbA1c 6.5−9.0%, fasting glucose 126-171 mg/dL) via standardized 100 g portions of sensorily preferred 7.5% variants (OF2, PF2) versus control (CF), measuring capillary glucose at 0, 30, 60, 90, and 120 min was examined. Results Proximate composition revealed dose-dependent increases in dietary fiber (12.61–17.55% vs. 7.86% in CF), reductions in available carbohydrates (48.24–52.06% vs. 55.16% in CF), and energy (349.72–368.31 kcal 100 g −1 vs. 384.98 kcal 100 g −1 in CF). Bar incorporated psyllium boosting minerals like K (1203.89 mg 100 g −1 in PF3), Mg (181.06 mg 100 g −1 in PF1), and Fe (3.94 mg 100 g in PF3). Regarding sugar profile, fructose (4.78–6.25% vs. 8.27% in CF), and glucose (4.68–6.09% vs. 8.20% in CF). Across formulations, the snacks retained high phenolic contents and antioxidant activity (TPC 475–598 mg GAE 100 g −1 ; DPPH-RSA 616–773 μmol TE 100 g −1 ), exhibited nutritionally balanced amino-acid profiles (essential amino acids 383–441 and non?essential amino acids 509–566 mg 100 g −1 ; EAA: NEAA ratio 0.68–0.87), and maintained a favorable fatty-acid pattern dominated by oleic and linoleic acids (MUFA 36.82–37.7%, PUFA 23.89–26.36%, with SFA 36.24–39.09%). Both OF2 and PF2 significantly blunted glucose excursions compared with control (p < 0.05), with PF2 superior (lower peaks at 60–120 min in both groups), confirming a low glycemic potential. Conclusion These findings position psyllium/oat-enriched LCDBSs as viable, culturally relevant options for glycemic control, weight management, and T2D dietary interventions.