Background: Accurate dietary intake data are critical to nutrition care planning. Commonly used food record charts (FRC) are paper-based, time consuming, require nutrient analysis estimations, and may provide limited accuracy. The present study aimed to validate Mobile Intake ® (MI) (an electronic food intake tool incorporating the five-point visual scale and providing automatic nutrient analysis) for usability and efficacy in quantifying dietary intake in the healthcare setting. Methods: Two research stages within two tertiary hospitals included: (1) examining criterion validity and efficiency of dietary intake quantification using FRC and MI compared to the gold standard weighed food record (WFR) in a controlled environment and (2) comparing efficiency and effectiveness of FRC and MI in usual care conditions. Results: In Stage 1, dietary intake was calculated (n = 90) with a significant difference across all methods (FRC, MI and WFR) for energy (p = 0.04), but not between MI and WFR (p = 1.00). The time taken for MI (40 s) was significantly less than FRC (174 s) and WFR (371 s) (p < 001). In Stage 2, dietary intake was determined (n = 210) using FRC and MI. Sufficient data to complete dietary analysis were available for 35% of meals from FRC compared to 98% from MI. Calculated mean daily energy intake (4764 ± 1432 kJ vs. 6636 ± 2519 kJ, p = 0.002) and mean daily protein intake (62.9 ± 12.7 g vs. 78.5 ± 22.2 g, p = 0.007) were significantly lower with FRC compared to MI. Average time to complete MI was 14.4 seconds. Conclusions: MI demonstrates efficacy as an accurate measure of dietary intake compared to WFR, as well as usability, providing faster, more accurate and comprehensive real-time intake data in practice than FRC.