The disclosed techniques provide systems and methods for generating content feeds with topic discovery capabilities. More specifically, various procedures are described for generating content feeds by selecting at least one of two of a first quantity of content items, a second quantity of content items, and a third quantity of content items. The first quantity of content items is selected based on a dynamically generated user interest profile associated with a particular user. The user interest profile can include a subset of first interest categories in which a specific user of a social networking system has indicated an interest. The second quantity of content items is selected based on a interest categories in which other users of the social networking system, having one or more characteristics that are the same or similar to the specific user, have indicated an interest. The third quantity of content items is selected randomly.