A Novel Method to Determine a Custom Sample Size for Image-Based Instagram Content Analysis

ObjectivesMost Instagram users are young people, and social media is often used to search nutrition information. Health interventions aimed at young people should consider such information sources. Content analyses of Instagram images offer insights into types of content that may influence nutrition-related decision making and health behaviors. However, the number of analyzed images in existing studies has varied, and methods to determine data-specific sample sizes to reach saturation have not been explored. We aimed to develop a method to determine sample sizes for image-based content analyses on Instagram. We piloted the method and determined the reliability by identifying the saturation point for content categorized under two separate nutrition-related hashtags.