Development of Australian portion size photographs to enhance self-administered online dietary assessments for adults

Aim: Technology is being used increasingly for dietary assessment, to streamline and improve the efficiency. These technologies allow for the inclusion of visual food portion images within the assessments rather than in addition to them as previously required. This paper describes the methodology for creating these food portion images using an online dietary assessment website (DietAdvice) as an example technology. The images include country-specific Australian food items, not previously available. Methods: Foods contained in the DietAdvice website were assessed to determine the number requiring food portion images. Preparation methods, recipes and portion sizes were determined for the foods, which varied from single foods through to cooked dishes and beverages. Foods were photographed by a professional photographer against a white background on a standard dinner plate or bowl with a standard of reference in each frame. Results: Approximately 200 food items required images, with varying portion sizes ranging from two to eight images per food item. Six hundred and thirty-one photographs were taken. Food such as ice-cream, burritos and fruit needed to be photographed quickly to prevent deterioration and ensure a quality real-to-life photographs. Conclusion: The art of photographing food portions itself is a difficult task. Inappropriate angles or lighting can make the food appear larger or smaller than it actually is. Timing is critical as the food can melt, wilt, collapse or discolour if the photo is not taken promptly. Clear labelling and a standard of reference for all photographs was necessary. The developed food portion images will allow users of the DietAdvice website to estimate portion sizes more accurately than text-based sizes alone, although validation is required.