Raw bioimpedance values of resistance (R), reactance (Xc), impedance (Z), and phase angle (PhA) are indicators of cell hydration, health, and membrane integrity. There is increasing interest in using these values as indicators of hydration and nutritional status, but effects of acute nutritional intake on raw bioimpedance values is currently unknown. PURPOSE: To determine the effects of acute feeding on raw bioimpedance values and derived body water estimates (total body water [TBW], extracellular water [ECW], intracellular water [ICW]) obtained from multi-frequency bioelectrical impedance spectroscopy (BIS). METHODS: Twenty-nine healthy young adults (59% Female; Age: 21.3 ± 2.7 yrs; Height: 172.5 ± 9.2 cm; Weight: 71.2 ± 10.3 kg) completed three randomly assigned feeding conditions: high carbohydrate (CHO: 116.5 g CHO; 882.5 g total; 0.83 ml fluid), high protein (PRO; 63.5 g PRO; 913 g total; 0.83 ml fluid), and fasted (FAST; 8 hrs fasted). Whole-body, multi-frequency BIS was completed one hour post-meal consumption. Differences in raw bioimpedance values and derived body water estimates between feeding conditions were evaluated using separate repeated measure ANOVAs covaried for average urine specific gravity to account for pre-visit hydration status. RESULTS: There were no significant differences in raw bioimpedance values [R (FAST, CHO, PRO means: 543.0, 545.1, 548.6 Ω; p = 0.418), Xc (67.2, 67.7, 67.7 Ω; p = 0.453), Z (547.2, 549.4, 552.8 Ω; p = 0.416), PhA (7.14, 7.16, 7.12°; p = 0.680)] or derived body water estimates [TBW (40.0, 40.0, 39.8 L; p = 0.289), ECW (16.1, 16.1, 16.1 L; p = 0.131), or ICW (23.9, 23.9, 23.8 L; p = 0.671)] between feeding conditions. CONCLUSION: Acute feeding did not alter raw bioimpedance values taken 1 hr post-meal in healthy young adults. Bioimpedance may not be sensitive to acute changes in nutrition/hydration or consumption of food/drink 1 hr prior to testing was not a long enough equilibration time. Acute food intake may not need to be restricted prior to bioimpedance measurements, which increases feasibility of application in clinical and athletic populations.