Objectives: Utilizing WISEcode food database (WISEdata) to assess the quality of nutrition information presented at online grocery shopping sites, with a focus on errors and omissions within food categories and across major retailers.
Methods: The WISEdata database is drawn from over 30 online grocery sites. Data were collected in 2022 and 2023. Analyses were conducted on 865,761 food records. Four error types were assessed: i) computation errors (e.g. saturated fat exceeding total fat); ii) omission errors (e.g. failure to declare a required nutrient in absolute grams or as %DV); iii) inclusion errors (e.g. declaring %DV where one does not exist); iv) unit errors (e.g.> mg is used when µg is appropriate). While other errors exist, these were chosen as the most consumer relevant. Individual as well as common groups of errors were assessed by aggregating across macro and micronutrients, specific food categories and specific online grocery sites.
Results: Computational errors were comparatively low for energy, serving size, total fat or total carbohydrates (when declared), error rates were 4.2%, 2.5%, 1.3% and 0.8% respectively. However, 73% of foods had errors in macronutrient declarations, with added sugar, fiber, trans fat, cholesterol and saturated fat being the most common. For example, failure to declare added sugar grams or %DV were the most prominent, occurring in 45% and 50% of food records, respectively. These were often accompanied by errors in trans fat, saturated fat and cholesterol declarations. Errors in declaration of micronutrients occurred in 64% of foods, with vitamin D, potassium, calcium and iron being most common. Error rates differed by food category. For example, Soups (canned and ready to eat) had an omission error rate of 53% for added sugars compared to Yogurts with an omission error rate of 19% for added sugars. Retailers also differed in error rates (indicating that different retailers utilize different databases), with the omission error for added sugars being most common.
Conclusions: We have shown here that the number of errors and omissions in the NFP can exceed 50% of the foods available across the online retail groceries for many nutrients. It is critical that accurate NFP information be accessible to consumers at the time of purchase, in other words, when shopping online.
