PROBLEM TO BE SOLVED: To control body weight to achieve a target value under the consideration of the daily variation of the body weight.SOLUTION: This body weight control device is provided with: a body weight acquisition unit for acquiring measurement data in which a body weight measurement value of a measurement object person is associated with a measurement date； a storage unit for storing the measurement data acquired by the body weight acquisition unit； a target acquisition unit 182 for calculating target daily variation quantity including the variation quantity of body weight in sleeping and the daily target increase/decrease quantity of body weight based on the measurement data of the storage unit； and an arithmetic unit 183 for calculating a target value to be a target in the case of measuring a sleeping side body weight value at a second timing on the sleeping side with respect to a rising side body weight value measured at a first timing on the rising side between rising and sleeping of the measurement object person, based on the target daily variation quantity acquired by the target acquisition unit 182. The target acquisition unit 182 calculates the daily target increase/decrease quantity so that the daily target increase/decrease quantity can be set to the increase/decrease rate of a prescribed range with respect to the rising side body weight value based on the measurement data of the storage unit.【課題】体重の日内変動を考慮しながら目標値となるように体重を管理する。【解決手段】被測定者の体重測定値と、測定日時とが関連付けされた測定データを取得するための体重取得部と、体重取得部により取得された測定データを格納するための記憶部と、就寝中の体重の変動量と、体重の日内目標増減量とを含む目標日内変動量を記憶部の測定データに基づき算出する目標取得部１８２と、目標所得部１８２により取得された目標日内変動量に基づいて、被測定者の起床から就寝までのうち起床側の第１タイミングで測定した起床側体重値に対して就寝側の第２タイミングで就寝側体重値を測定する際の目標となるべき目標値を算出する演算部１８３と、を備え、目標取得部１８２は、記憶部の測定データに基づき、日内目標増減量が起床側体重値に対して所定範囲の増減率となるように、日内目標増減量を算出する。【選択図】図３
