Behavioral Nudging Alcohol Purchasing Behavior on Online Grocery Shopping Platforms

Abstract

This thesis explores how online grocery platforms can support alcohol reduction among light to moderate drinkers through targeted, co-designed health interventions via the leveraging of choice architecture. While prior research largely focuses on heavy drinkers or product availability adjustments, this work addresses a critical gap by centering on light to moderate drinkers, a significant but under-engaged demographic in digital alcohol harm reduction, especially as healthcare networks begin to focus on personalized and preventative care. The thesis unfolds in four parts.

In the first part (Study 1), I investigated the role of deceptive design patterns, or "sludge," in influencing alcohol purchases online. I conducted a heuristic evaluation of 11 UK online grocery platforms which revealed widespread use of sludge, prompting the development of five design interventions. These were iterated through an online alcohol purchasing task and two follow-up activities including a design workshop and swap acceptability survey. Participants favored interventions such as alcohol unit indicators, product grading imagery, and neutral-toned health warnings.

In the second part (Study 2), I investigated further how to engage light to moderate drinkers in preventative health interventions by exploring their motivations and preferences using questionnaires and interviews. Thematic analysis revealed four key factors for effective design: health and wellness promotion, personal empowerment, sociocultural context, and user-centeredness which informed a practical alcohol intervention conceptual model.

In the fourth part, I conducted a reflexive market analysis to trace the evolution of no- and low-alcohol (NoLo) options in UK online grocery platforms from the start of my PhD in 2022 to its conclusion in 2025. This analysis revealed growing product availability and changing marketing strategies, but also a persistent premium pricing trend that may limit accessibility. My findings emphasize the need for affordability strategies and personalized nudging using AI.

Together, these works offer a comprehensive approach to designing for alcohol reduction in digital retail environments, highlighting both user needs and system-level opportunities. This work contributes to public health, HCI, and digital service design by proposing inclusive, early-stage interventions for a largely overlooked population.

Date of Award	17 Jun 2025
Original language	English
Awarding Institution	University of Bristol
Supervisor	Anne Roudaut (Supervisor) & Angela S Attwood (Supervisor)