In order to avoid fatigue during an important match it is important for you to adjust your diet. The amount of food you need to eat differs depending on your level of play. As an amateur, if you try to eat the same volume of food as a professional, you would probably gain weight.
Carbohydrate is the key energy-providing nutrient, so you must optimise the intake during the days leading up to and on the day of your match. In low key competition, or if you do only little running in a game, your pre-match meal might not need to focus so much on carbohydrate.
However, if you are an intense competition player, you should aim to eat 1-4 g/kg body weight of carbohydrate during the 6 hours before match or training. Here are five different examples of foods that each provides you with 140 g carbohydrate pre-competition* (2 g/kg for a 70 kg player):
(*note that other foods may be eaten at the meal)
Do not make the mistake to eat too little carbohydrate (less than 1 g per kg body weight) during this period. You need a certain amount of carbohydrate to sustain you throughout the match.
You should also pay attention to optimise the water and salt levels in your body. Drink enough fluids with your meals to ensure that you are well-hydrated.
Consensus Statement: Nutrition for football: the FIFA/F-MARC Consensus Conference.
Journal of Sports Sciences 2006;24(7):663-664; and other articles of the supplement “Nutrition and football”.