Does highlighting lower-calorie options online prompt people to buy them?

Food background - food blogging, reading about food, searching for recipes or ordering food online. Flat design style.Swaps are used by health-promotion apps and online supermarkets to promote lower-calorie alternatives.Using an experimental online supermarket, our study found that:

  • offering swaps did not lead to participants buying fewer calories as only a quarter of swaps were accepted, and half the participants refused all suggested swaps.
  • participants who accepted the swaps did purchase fewer calories.


In conclusion, unless we can encourage more swaps to be accepted this intervention is unlikely to be successful at improving the healthiness of the food people buy.

Offering within-category food swaps to reduce energy density of food purchases: a study using an experimental online supermarket . Forwood, Ahern, Marteau & Jebb. 2015.

Access full text.