Young athletes are growing and training at the same time, which means their fuelling needs are higher than most people realise. The goal isn't complicated diets or supplements — it's getting enough good-quality food in, consistently, around the demands of training and school. Get the basics right and everything else takes care of itself.
Before training
Aim for a balanced meal containing carbohydrates and some protein about two to three hours before a session — think pasta, rice or potatoes with chicken, fish or beans, plus some vegetables. If there's only an hour to spare, a smaller, carb-focused snack such as a banana, toast with honey, or a yoghurt works well. The aim is to arrive energised, not stuffed or starving.
After training
Recovery starts with the next meal. Within a couple of hours of finishing, young athletes should eat a normal balanced meal with carbohydrates to refill energy stores and protein to support muscle repair and growth. A glass of milk and a piece of fruit is a perfectly good interim snack if the next meal is a while away.
Hydration
Encourage regular sips of water through the day, not just during sport. Bringing a labelled water bottle to every session builds the habit. For most training, water is all that's needed; sports drinks are rarely necessary for youth athletes unless sessions are very long or in extreme heat.
Above all, keep it sustainable and enjoyable. Consistent, varied, mostly-whole-food eating will support performance and healthy growth far better than any single "superfood" or supplement.