The purpose of the invention is to provide a material for weight reduction diet food and the processed food using the same, that is a natural food product obtained from the materials eaten in everyday life, and very safe to the human body. There is provided a material for processed food for weight reduction diets, wherein active ingredients including histidine were extracted from Bonito essence. In addition, the present invention provides the material for processed food for weight reduction diets, wherein 12,000 mg-20,000 mg weight % of histidine is included. Furthermore, the processed food for weight reduction diets using the above-mentioned material for processed food for weight reduction diets is offered. As examples of such processed food, besides supplements in tablets and capsules soup stock powder, Furikake, and feeds for animals. etc, can be considered,