Objective: Individuals with inefficient executive (higher level cognitive) function have a reduced ability to resist dietary temptation. The present study aimed to design and test a theory-based point-of-purchase intervention for coffee shops that reduced the calorie content of customers' purchases by reducing the need for executive function (EF) at the moment of choice. Methods: Key facets of EF were identified by a multidisciplinary group and used to develop a point-of-purchase intervention (signage). This intervention was evaluated in a randomized controlled trial (RCT) in a public coffee shop on consumer purchases of >20,000 snacks and drinks over 12 weeks. A sample of customers (n = 128) was recruited to complete an embedded cross-sectional study measuring EF strength, dietary intentions, typical purchases, and purchases made after exposure to the intervention. Results: The proportion of snack purchases that were high in calorie reduced significantly (t(10) = 2.34, p = .04) in intervention weeks relative to control. High calorie drink purchases were also lower in intervention than control weeks, however, this difference was not significant (t(10) = 1.56, p = .15). On average, customers purchased items containing 66 calories < usual after exposure to the intervention. The magnitude of the intervention's positive effect on customer behavior increased as EF strength decreased (β = .24, p = .03). Conclusions: The calorie content of cafe purchases can be lowered by reducing the cognitive demands of healthy food choice at the moment of purchase, especially in those with poor EF. Environmental changes like these have the potential to help achieve population weight control. (PsycINFO Database Record (c) 2014 APA, all rights reserved).