Most pros sacrifice food as a love throughout their career in any sport, so what they eat any given day is not much different to what they'd do on other days. As a general umbrella, I'd think they take more carbs in the morning for energy, balance of fibre, carb and fat by noon. On a match day a 2pm , if it were me, I'd have lunch early noon, by 12, so that in 2 hours, that food is out of stomach and in the intestines, ready to supply energy. Specific foods will vary based on the native food habits obviously, I'd take rice for carbs, Federer might have pasta. Novak may take bread without gluten, it's all carbs in the end.
