PURPOSE: To aid the will to continue a diet liable to be broken by altering the configuration of a configuration section capable of taking at least two different configurations when the removal of food held by a food holding means is detected.

CONSTITUTION: A configuration section 1 capable of taking at least two different configurations is constitutionally provided with a doll 11 of a design for reminding one of a pig for example. The doll 11 is deformed to be successively expanded and fatted by air sent from a pump 13. Also, air in the doll 11 is exhausted through an exhaust valve 15. The pump 13 and exhaust valve 15 are operated by a command from a control section 7, i.e., the doll 11 is first set to the lean state, and food like cake is mounted on a cake holding section 51 of a sensor section 5. When the taking-out of the cake is detected by a sensor 53, an uttering section 3 is operated through the control section 7 to utter the words like 'grow fat!' and at the same time the pump 13 is driven to expand the doll 11 to the fatted state.