Exploring the correlation between self-reported preferences and actual purchases of nutrition labeled products

•We combine purchase data and self-reported preferences towards the Keyhole label.•Self-reported preferences and purchases of Keyhole items are positively correlated.•We find a positive relation between Keyhole labeled purchases and BMI.•Correlation between self-reported preferences and purchases are independent of BMI.•Healthy Eating Index is positively correlated with Keyhole purchases.