Validation Data Based on a Web-Based Photographic Questionnaire for Assessment of Skills in Estimating Carbohydrate Portion Sizes in Adults with Type 1 Diabetes

The data in this article present differences and agreements in estimating the carbohydrate content in foods based on web-based photographs vs. real foods in adults with type 1 diabetes (T1D). The Carbohydrate Photographic Questionnaire (CPQ) consists of photograph series of 20 commonly eaten high-carbohydrate foods in the Nordic countries. The CPQ was developed as a simple tool for assessing skills in accurate estimation of the carbohydrate content of foods. Ninety-six adults (52% females) on insulin pump therapy attended the study. Error estimates for the true carbohydrate content were calculated based on the participants’ estimations from the CPQ and from real foods.
Cross-classifications indicated an overall moderate agreement in estimation errors between the CPQ and real foods. The median percentage of participants classified into the same error category when estimating the carbohydrate content in real foods vs. the CPQ was 39% (interquartile range (IQR) 35–50%). The highest correct classification was obtained for grapes (79%) while lasagne (15%) had the lowest correct classification.