[PROBLEMS] To provide a drug or a food for specified health uses aiming at slowing the onset or progress of mobility impairment relating to amyotrophic lateral sclerosis. [MEANS FOR SOLVING PROBLEMS] An agent containing D-allose as the active ingredient and aiming at slowing the onset or progress of mobility impairment relating to amyotrophic lateral sclerosis. A composition in the form of a food, a drink or a drug which contains the agent for slowing the onset or progress as described above. The above-described composition wherein the daily dose of D-allose is from 0.5 to 50 g. A food or a drink containing D-allose as the active ingredient which is indicated as being used for slowing the onset or progress of mobility impairment relating to amyotrophic lateral sclerosis. A method of slowing the onset or progress of mobility impairment relating to amyotrophic lateral sclerosis in a human subject which comprises administering or feeding D-allose in an efficacious amount to the subject. A method of treating a human subject diagnosed as suffering from amyotrophic lateral sclerosis which comprises administering or feeding to the subject D-allose in an efficacious amount for slowing the progress of mobility impairment.
