A shift to more sustainable diets is needed to ensure food security and to reduce the pressure on the environment. Yet, many consumers have misconceptions about the environmental impacts of their diets and lack knowledge on how to prepare sustainable meals. This study uses a mixed-methods approach to develop four information nudges and to test their impact on dietary choices among a representative sample of Dutch consumers. A 2 x 2 between-subjects design crossing type of information (procedural versus declarative) with type of impacts (health versus environmental) is applied. The environmental impact is measured in terms of CO2 emissions, land use and water use. We find that pre-intervention knowledge about sustainable or healthy diets is related to the sustainability of participants’ dietary choices. Procedural knowledge on how to prepare a healthier meal has the greatest potential to influence dietary behavior, in particular for participants without prior self-reported dietary restrictions.