The aim was to explore how the behaviour of consumers changed while they selected food in a supermarket environment after they were reminded about weight management. This investigation was carried out from the perspective of selection criteria, reading of package labels, nutritional quality of the products selected and time taken to select a product.The subjects, who were actively watching their weight, participated in two consecutive tasks in a supermarket. They were given a shopping list of eleven food categories and asked to think aloud while selecting from each category a product they usually buy and a product they would use for weight management. The data (n 792 selections) were collected through interviews and a verbal analysis protocol combined with wireless audio-visual observation.Thirty-six consumers were recruited from a sample of 367 supermarket customers.Kuopio, Finland.The subjects' behaviour changed radically after they were reminded about weight management. In the first selection, taste and familiarity were the main food selection criteria while in the latter selection the energy/fat content predominated. Consequently, the nutritional quality of products improved greatly because subjects read package labels twice as much in the latter selection. The time taken to select a product increased significantly, on average, from 23 (sd 10) to 60 (sd 51) s/product (P = 0·000).Only by reminding consumers about weight management was there a significant impact on their food selection behaviour. Marketing communication should be developed which quickly and easily promotes consumers' awareness of healthy food in supermarkets.