Validation of a self-administered web-based 24-h dietary recall for individuals with severe obesity undergoing...

The study aimed to assess the validity of a web-based 24-h recall (R24W) for measuring dietary intakes in individuals living with severe obesity who are awaiting bariatric surgery, compared to a food record (FR), currently used in clinical settings.

A total of 51 individuals with severe obesity awaiting bariatric surgery were recruited (mean age: 45.3 ± 8.0 years). Before surgery, participants completed three R24W and a 3-day FR. Nutritional intakes were derived from the 2015 version of the Canadian Nutrient File. Mean differences in energy and nutrient intakes were assessed using percent differences and paired t-tests. Spearman correlations evaluated the associations between tools, while cross-classification analyses, weighted kappa scores, and Bland-Altman analyses were used to assess the degree of agreement. To determine validity, a seven-criterion validity analysis proposed by Lombard et al. was applied. The R24W was considered valid if it had three or fewer poor scores.

Energy, carbohydrates, proteins, fats, saturated fat, dietary fiber, vitamin B6, vitamin B12, vitamin C, vitamin D, calcium, iron, magnesium, potassium, and sodium had three or fewer poor scores, suggesting that the R24W provides an estimation of these nutrient intakes similar to the FR. In contrast, vitamin A, riboflavin, thiamin, folate, niacin, and phosphorus scored below the threshold of poor scores.

The R24W demonstrated good validity for assessing energy intake, macronutrients, and several key nutrients (e.g., iron and vitamin D) in this population. These findings support the use of the R24W as a clinical and valid tool for dietary assessment in the bariatric population.