A health monitoring assist system includes: a unit that acquires time-series data of an activity index that indicates an amount of an activity conducted by a subject a unit that acquires time-series data of a biological index measured from, and relating to health of, the subject an estimation unit that estimates an amount of time lag between a change in the activity index and a resultant change appearing in the biological index based on a result of comparison between the time-series data of the activity index and the time-series data of the biological index and a unit that provides the subject with assist information that indicates that an effect caused by the activity of the subject is apparent in a value of the biological index after the amount of time lag from a time point when the activity was conducted, based on an estimation result of the estimation unit.
