The first aspect of nutrition is periodization. It is very difficult to be in a strict diet in training year round. Personally, I have to have times where I “loosen the belt” and enjoy a good cheeseburger. So, understand that just as there is periodization in your training, there is periodization in your nutrition. For example, when you are narrowing in on race day you may become very strict in your diet about 8-12 weeks before race day. This gives you ample time to lose any extra weight you are carrying and to maximize your training days with quality foods.
After the race, you may take a reward week to eat some extra food or enjoy a meal that just is not in your strict training diet. You shouldn’t feel bad about this cheat period and go enjoy a great desert. Once this cheat week or cheat day is over jump right back into your more strict diet to prepare for your next race. In the offseason, it is important to enjoy some not so strict foods, but be careful you can put on too much weight in the offseason.