Meal before swimming competition.
Power before a swim should be rich in carbohydrates, which are digested faster and available to replenish muscle and liver glycogen. Ideally ingest about 3 hours before the competition to have time to digest.
For example pastas, breads, tortillas, crackers, oatmeal.
Beware sugar to swim.
When you go swimming avoid consuming refined sugars source of food as these cause intense energy overhead but very short duration that alters the metabolic balance. It is best to shop eat foods like cereal, crackers unfilled, low-fat yogurt or fruit.