Smartphone app study finds label use lead to healthier food choices

Research using a smartphone app has found people buy healthier foods if they use food labels.

In newly published research, "Do nutrition labels influence healthier food choices? Analysis of label viewing behaviour and subsequent food purchases in a labelling intervention trial," foods purchased by shoppers after looking at the label were about 13 percent healthier than foods where labels were viewed but the food was not then purchased.

Lead author, Professor Cliona Ni Mhurchu, of the University of Auckland's National Institute for Health Innovation, says; "There was a significant association between label use and the healthiness of products purchased. Nutrition label use may therefore lead to healthier food purchases."

Called the Starlight study, the four-week randomised, controlled trial studied the effects of three different types of nutrition labels on consumer food purchases: Traffic Light Labels, Health Star Rating labels, or Nutrition Information Panels.

Between October 2014 and November 2015, 1,357 household shoppers across New Zealand who owned smartphones (iOS or Android) aged 18 years or older were enrolled in the study.

Participants were randomly assigned to receive either Traffic Light Labels (TLL), Health Star Rating labels (HSR), or a non-interpretive, control label (Nutrition Information Panel (NIP)) via their smartphone.

Smartphone technology allowed participants to scan barcodes of packaged foods with their phone cameras and receive randomly allocated labels on their phone screen, and to record their food purchases.

The study app provided objectively recorded data on label viewing behaviour and food purchases over a four-week period.

Over the four-week study, participants viewed nutrition labels for and/or purchased 66,915 barcoded packaged products. Labels were viewed for 23 per cent of all purchased products.

Shoppers were most likely to view labels for convenience foods, cereals, snack foods, and bread. They were least likely to view labels for foods that are generally easily recognised as unhealthy (e.g. sugar and honey products) or healthy (e.g. fish, fruit and vegetables).

Previous studies were either limited to a small number of specific food categories, or they combined all food category data together.

"So our analysis extends the field by examining and reporting on label use by food group and by investigating the association between label use and the healthiness of products subsequently purchased by shoppers."

Products that participants viewed the label and purchased were significantly healthier than products where labels were viewed but the product was not bought.