An information processor for estimating a digestibility of food consumed by a user, comprising: a first receiver for receiving a plurality of pieces of heart rate information measured at specified time intervals from a heart rate signal measurement device carried by the user; a second receiver for receiving information of a meal start time and a meal finish time of the user; a line calculation unit for calculating, based on a trend indicated by the plurality of pieces of heart rate information, in which the heart rate rises with time after meal and then drops, a first-order approximation line that approximates a change in the heart rate in a predetermined time slot of the trend after a time of measurement of a peak value of the heart rate by a line; a correction unit for correcting the first-order approximation line based on a trend indicated by the plurality of pieces of heart rate information in which the heart rate rises with time during meal and then drops; a time specification unit for specifying a digestion finish time indicating the time when digestion of the food is completed, based on the corrected first-order approximation line and the heart rate at the meal start time; and a digestibility estimation unit for estimating the digestibility at a current time, which is obtained by calculating an equation which is [(the current time - the meal finish time) / (a first time between the meal finish time and a time of measurement of the peak value indicating a maximum value of the heart rate after the meal + a second time between the time of measurement of the peak value and the digestion finish time)], wherein the correction unit is configured to execute processing of: calculating an index value indicating eating activity energy from the trend in which the heart rate rises with time during meal and then drops, extracting a corrected value corresponding to the index value calculated by the line calculation unit, from corrected value management information indicating a correspondence relationship between the index value and the corrected value, and correcting the first-order approximation line with the corrected value. a first receiver for receiving a plurality of pieces of heart rate information measured at specified time intervals from a heart rate signal measurement device carried by the user; a second receiver for receiving information of a meal start time and a meal finish time of the user; a line calculation unit for calculating, based on a trend indicated by the plurality of pieces of heart rate information, in which the heart rate rises with time after meal and then drops, a first-order approximation line that approximates a change in the heart rate in a predetermined time slot of the trend after a time of measurement of a peak value of the heart rate by a line; a correction unit for correcting the first-order approximation line based on a trend indicated by the plurality of pieces of heart rate information in which the heart rate rises with time during meal and then drops; a time specification unit for specifying a digestion finish time indicating the time when digestion of the food is completed, based on the corrected first-order approximation line and the heart rate at the meal start time; and a digestibility estimation unit for estimating the digestibility at a current time, which is obtained by calculating an equation which is [(the current time - the meal finish time) / (a first time between the meal finish time and a time of measurement of the peak value indicating a maximum value of the heart rate after the meal + a second time between the time of measurement of the peak value and the digestion finish time)], wherein the correction unit is configured to execute processing of: calculating an index value indicating eating activity energy from the trend in which the heart rate rises with time during meal and then drops, extracting a corrected value corresponding to the index value calculated by the line calculation unit, from corrected value management information indicating a correspondence relationship between the index value and the corrected value, and correcting the first-order approximation line with the corrected value. calculating an index value indicating eating activity energy from the trend in which the heart rate rises with time during meal and then drops, extracting a corrected value corresponding to the index value calculated by the line calculation unit, from corrected value management information indicating a correspondence relationship between the index value and the corrected value, and correcting the first-order approximation line with the corrected value.