Significant benefits arise from being able to capture dietary or nutritional intake information automatically or semi-automatically. These include the ability for individuals to know and understand their nutritional intake and hence improve their diet and health. To date, only highly manual processes such as 24-hour recall, food diaries, and food journals have been utilized which have been overly cumbersome for widespread adoption. Emerging informatics, computer vision, mobile computing, and sensor-based approaches are likely to play a role in further automating the capture of dietary intake information and these are becoming increasingly utilizable through such advents as the rapid and ubiquitous uptake of smartphones with built-in digital cameras and other sensors. In this paper, we review the state of the art of technologies for automatic capture of dietary intake information and identify significant outstanding research problems and promising directions.