The factor that would increase the basal metabolic rate (BMR) is weight gain, as a larger body mass generally raises energy requirements. Maintaining a normal body temperature supports BMR, while being underweight and aging typically lower BMR. Therefore, out of the options, weight gain is the most effective at increasing BMR. ;
The factor that would increase BMR is weight gain since a larger body mass requires more energy. Other options, like being underweight and getting older, generally lower BMR. Maintaining a normal body temperature supports metabolic functions but does not directly increase BMR.
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