Dietary under-reporting: what foods and which meals are typically under-reported?

Little objective information exists regarding which foods and meals are typically under-reported during retrospective self-reported dietary assessments. Automated wearable cameras record dietary behaviours in free-living settings and allow the context of under-reporting to be explored. As part of a study to validate image-assisted dietary assessment, 40 participants wore a wearable camera on days before three image-assisted 24-h dietary recalls. The foods and meals were typically under-reported, and the environmental and social contexts of under-reporting were assessed. Under-reporting occurred most frequently during afternoon snacks (75/265 foods), dinner (54/265 foods) and breakfast (44/265 foods). Snack foods were most frequently unreported during afternoon snacks, and condiments were most frequently under-reported at breakfasts. No clear pattern of social or environmental contexts for under-reporting was observed. Wearable cameras can identify when specific foods are likely to be under-reported during retrospective dietary assessments. Problematic foods and meals identified could be given additional attention during dietary assessments.