The effectiveness of video training on accuracy of food portion size estimation.

摘要

Food portion size estimation error is a notable limitation when collecting accurate dietary intake data and affects validity of conclusions about the relationship between dietary intake and disease. A variety of methods exist for collection of food consumption data and include the use of portion size estimation aids (PSEAs) to improve accuracy of food portion size estimation. Currently there are no established guidelines for the use of PSEAs. An alternative to the available PSEAs is the use of video instruction that has been used effectively in other areas of patient education. Video on food portion sizes can be viewed repeatedly (with TV/video player or computer) potentially saving time, reducing cost, and improving standardization. This research was designed to test the effectiveness of food portion size video training on accuracy of food portion size estimation and to validate its use within the context of two dietary assessment methods.; The first study determined that the use of video immediately prior to an estimation session significantly improved the accuracy of food portion sizes estimated when compared to no training. In the second study, a 24-hour time delay did not increase the error of food portion size estimation errors. Actual errors of estimation after training with video, regardless of the 24-hour time delay, were three-fourths to half the error of the untrained subjects. The third study demonstrated that subjects trained with video (delivered in-person or via computer) had the largest percentage of exact estimations and had a greater or equal number of food items with actual error of less than ±25% as compared to subjects trained with other methods. The results of the final study indicated that use of video within the context of a 24-hour recall yielded portions size estimations and nutrient intake data of similar quality as that obtained from estimations given by subjects trained with food models. Results were less convincing for data obtained from using food records.; Video training on food portion sizes is an efficient, effective, and convenient way to improve accuracy of food portion size estimation resulting in similar errors of estimation as does training with traditional methods.