Final answer:
The number of calories a person should eat each day depends on various factors such as age, gender, height, weight, and activity level.
Step-by-step explanation:
The number of calories a person should eat each day depends on various factors such as age, gender, height, weight, and activity level. On average, a person needs 1500 to 2000 calories per day to sustain daily activities. However, individual needs may vary. For example, a 15-year-old female who runs three miles each day would require more calories than the average.