A body weight management device includes: a change obtainment unit for obtaining an intra-day body weight change value on a daily basis based body weight measurement values of a measurement subject measured on a daily basis an achievement rate obtainment unit for comparing the intra-day body weight change value obtained by the change obtainment unit with an intra-day target weight loss value and obtaining, based on a result of the comparison, a target achievement rate indicating a percentage of total days in a predetermined period in which the intra-day body weight change value has reached the intra-day target weight loss value and a target obtainment unit for obtaining, based on the target achievement rate obtained by the achievement rate obtainment unit, a new intra-day target weight loss value to serve as a target for future body weight measurement.
