To perform well, a swimmer needs to eat and drink well.
In case this helps, here are some links to the information available on the Swim England and British Swimming websites:
https://www.britishswimming.org/performance/swimming/training-and-sports-science/nutrition/
https://www.swimming.org/sport/nutritional-advice/
https://www.swimming.org/sport/breakfast-ideas-for-young-swimmers/
https://www.swimming.org/sport/dinner-ideas-young-competitive-swimmers/
https://www.swimming.org/sport/healthy-lunchbox-ideas/
https://www.swimming.org/masters/masters-training-room/masters-swimming-canteen/
https://www.swimming.org/masters/what-to-eat-during-swimming-competitions/
