A challenging target value of a lifestyle that is more appropriate for a user is calculated by correcting an influence of an answering tendency of the user. A target value recording unit (602) of a health care assisting device (600) receives an input of a target value of biological information of the user that is concerned with a challenging item relating to the lifestyle, at the beginning of a predetermined period of time. A measurement value input unit (603) receives an input of a measurement value of the biological information of the user, after the end of the period. An answer sheet input unit (604) receives an input of an answer value which is a self-rated value of the user regarding an achievement level with respect to the target value of the challenging item relating to the lifestyle, after the end of the period. An amendment target value generation unit compares the measurement value of the biological information inputted after the end of the period and the target value of the biological information inputted at the beginning of the period, and corrects the inputted answer value in accordance with the comparison result. A target value update unit (611) decides a next target value of the challenging item relating to the lifestyle that is to be achieved in a subsequent period, on the basis of the post-correction answer value.