OBJECTIVES: Children's food choices are influenced by school, family and community environments; but obesogenic exposures in these environments are difficult to measure. Innovative tools such as wearable cameras are being developed to quantify children's exposures to such factors. We aimed to assess the features required and acceptability of these tools in two urban contexts going through a rapid nutrition transition: Beirut (Lebanon) and Tunis (Tunisia). METHODS: A user-centered design approach engaged schoolchildren (aged 10–12y), parents and school staff in twelve design workshops in Beirut and Tunis. These included discussions, mind-mapping and storyboarding to identify challenges associated with wearable cameras and to inform the design of a data-collection model that meets the cultural and ethical requirements specified. Discussions were audio-recorded, transcribed and analyzed thematically along with the mind-maps and storyboards. RESULTS: Commonly reported challenges were: invading children's and third-parties’ privacy; distracting school-students; and inaccurate data due to behavioral changes. Safety issues related to photo-capture in public (third-party questioning/aggression) only emerged in Tunisia since Lebanese parents stated that children were rarely unsupervised in public. To overcome these challenges, participants suggested wearable cameras capturing exposures automatically, for a short period. Two rounds of image-filtering were proposed to safeguard privacy: automated selection of pictures with food-related exposures, followed by parental manual screening. To protect anonymity, participants suggested automated blurring of faces. CONCLUSIONS: Objectively measuring children's environments with wearable cameras was deemed acceptable in these two contexts, with substantial privacy and data protection guidelines. The suggested model has been developed and will be tested in future research. FUNDING SOURCES: International Development Research Center (IDRC).