Final answer:
The number of calories a 15-year-old girl needs to maintain her weight varies based on activity level and body composition; the average requirement is 1500 to 2000 calories per day. A balance between calorie consumption and energy expenditure is needed to avoid weight gain.
Step-by-step explanation:
The number of calories a 15-year-old girl should consume daily to maintain her weight varies based on several factors including her body composition, height, activity level, and whether she undergoes regular physical activity. On average, teenagers need about 1500 to 2000 calories per day to sustain their daily activities. However, this is a generalized range; an active teenager may require more calories to support their energy expenditure, such as a 15-year-old who runs three miles a day. It's also important to note that consistently eating just 200 extra calories per day can lead to significant weight gain over time.
Eating a balanced diet and getting regular exercise can help in managing calorie intake and maintaining a healthy weight. To avoid weight gain, it is crucial to balance calorie intake with the calories used. It is simple thermochemistry: if you consume more calories than your body uses, the surplus will be stored as fat, leading to weight gain. Conversely, to lose weight, you need to create a calorie deficit. Diet and exercise are important components of this balance, ensuring a teenager maintains a healthy weight without compromising nutritional needs.