question: Although many deem intermittent fasting (IF) a healthy dietary regimen, there is a paucity of scientific evidence to corroborate IF health benefits in human studies However, its comparative ease and the emphasized benefits in the light of COVID-19 (e g , weight loss and immunization improvement) have led to the increase of IF adoption A vast number of intermittent fasters have not sought consultation from health professionals, which can bring adverse health effects Most intermittent fasters use mobile apps to get assistance for IF Types of assistance offered by the IF mobile applications may range from tracking (e g , fasting periods, calorie intake) to obtaining knowledge about IF However, it is unclear how much people are using the features for learning more about IF which is crucial to making healthier decisions in the IF adoption process Thus, we organized our study into two stages for establishing design implications that further encourage a safety-conscious and user-friendly IF experience We first investigated how IF app users who have chosen apps that provide extensive IF-specific knowledge acquire the said knowledge via (i) topic modeling of user app reviews, (ii) detecting modularity in co-word maps drawn from reviews specific to IF information acquisition, (iii) locating the position of keywords indicating information acquisition in the reviews Then, we examined how users judge the effectiveness of knowledge provision interfaces in obtaining information We investigated this aspect with an interface ranking user task for information tabs and organized user rationale using manual coding and co-word mapping © 2021, Springer Nature Switzerland AG