Devices, systems, and methods are provided for monitoring hydration of a user that include a fluid container including one or more sensors, e.g., pressure sensors, accelerometers, and the like, for identifying when the user consumes fluid from the container and/or determining the volume of fluid consumed. The fluid container may communicate with a mobile electronic device to monitor at least one of volume and frequency of fluid consumption and provide an output to the user related to compliance with hydration recommendations. Optionally, the system may also include a fitness tracker for monitoring one or more aspects of the user's physical activity； and the mobile device may monitor hydration of the user based at least in part on the user's physical activity.
