Why calorie targets are not the answer
Energy needs vary enormously with growth stage, training load and body size, and adolescents are poor at estimating intake. Chasing a target number also risks introducing a focus on numbers that is unhelpful at this age.
Outcome signals are more useful: is she growing as expected, are her periods regular, does she have energy through the day, and is she improving in training?
Signs that fuelling is adequate
- Growing along her expected trajectory.
- Regular periods once established.
- Good energy at school and in the last twenty minutes of training.
- Performance improving over months.
- Recovering from sessions within a day or two.
- Enjoying food without anxiety or rigid rules.
Signs that it is not
- Periods irregular, late to start, or stopped.
- Recurrent bone stress injuries or slow-healing injuries.
- Persistent fatigue and frequent minor illness.
- Performance plateau or decline despite consistent training.
- Weight loss, or no weight gain during a growth spurt.
- Skipping meals, cutting food groups, or distress around eating.
The practical fuelling routine
- Three meals plus two to three snacks on training days.
- Something containing carbohydrate 1–3 hours before training.
- A snack with carbohydrate and protein within an hour after training.
- Carbohydrate at every meal, it is the main fuel for high-intensity sport.
- Calcium and vitamin D sources daily for bone development.
- Iron-rich foods regularly, particularly once periods have started.
The schedule problem
Most under-fuelling in young athletes is logistical. School lunch at midday, training at six, dinner at nine leaves a very long gap on the busiest day of the week. The fix is usually a substantial snack in the car and a planned post-training meal, not a nutrition overhaul.
Packing food should be as routine as packing boots.
When to get help
Involve a GP if periods are absent or have stopped, if there have been bone stress injuries, if there is unexplained weight loss, or if there are signs of disordered eating such as rigid rules, secrecy, or distress around food.
These situations are common in youth sport, they respond well when addressed early, and they get considerably harder to treat if left.