A human heart consumes about 1 J per heartbeat. About how many joules of energy must food furnish to a person each day to supply this energy? For comparison purposes, one nutritionist's calorie of food energy is equivalent to 4184 J.

1 answer

To calculate how many joules of energy food must supply to a person each day to support their heart's energy needs, we first need to determine the number of heartbeats per day.

Assuming an average heart rate of 60 beats per minute, there are:
60 beats/minute x 60 minutes/hour x 24 hours/day = 86,400 beats/day

Therefore, each day, a person's heart consumes:
1 J/beat x 86,400 beats = 86,400 J

To convert this energy into nutritionist's calories:
86,400 J ÷ 4184 J/calorie ≈ 20.7 calories

Therefore, food must supply approximately 20.7 calories per day to meet the energy needs of a person's heart.