This book describes and examines three EU legal frameworks (EU competition law, EU consumer law, and EU fundamental rights law) that may affect the extent to which consumers purchase more sustainably. In doing so, this book goes beyond a rationalist understanding of the interpretation and application of EU law. Rational approaches have severely impacted the interpretation and application of EU law. Practice shows, however, that the implications of using a noncritical application of rationalist approaches in the interpretation and application of EU competition law, EU consumer law, and EU fundamental rights law to sustainability labels may have an inhibiting effect on sustainable consumption. The book offers remedies to overcome this inhibitive effect by critically applying insights from cognitive science and behavioral economics in the legal interpretation and application of EU law.