There are many arguments around over the best diet for a footballer or for sporting professionals generally. Overall, though, there are certain factors that most sporting nutrition experts would agree on:
Footballers need a good level of carbohydrates to give energy and stamina. It is important that most of these are complex carbohydrates such as those found in wholewheat pasta, brown rice, potatoes and vegetables rather than simple ones such as the contents of cakes, white bread etc. Complex carbs take longer to break down so the player gets a long term energy supply.
Protein is also important to build up muscles, especially the high biological value protein found in fish, eggs, meat and soya. In the past sports people were advised to eat lots of red meat but now other sources of protein are preferred.
A good variety of different colour vegetables and fruits, as well as some nuts, pulses and grains wiil ensure a varied intake of vitamins and other nutrients.