Estimation of food portion sizes: effectiveness of training.

This study compared the effectiveness of two types of training on the ability to estimate food portion sizes. Training consisted of a 10-minute group session in which subjects practiced measuring various solid and liquid foods with household measures. A second group of subjects viewed food models of solids and liquids. Immediately following training, subjects individually quantified portion sizes of foods displayed as a breakfast, lunch, and dinner. A third group, whose members received no training, also estimated the same food portion sizes. Results indicated no statistically significant difference (p greater than .05) between the two types of training using both parametric and non-parametric tests. When the trained groups were combined and compared with the untrained group, MANOVA analysis indicated training made a significant difference (p less than .05) in improving estimation for some food items. A Kolmogorov-Smirnov test also supported the hypothesis that training improved estimation for some, but not all, food items. Although a significant difference was not found for all food items, the data lend some support to the practice of using food models or household measures to enhance the ability to estimate food portion sizes more accurately, even when training is undertaken in short group sessions.