FIT5 How-tos :: The Optimum Diet :: Simple rules of the best diet :: Why should you create an eating diary?

If necessary, take notes about when and what you eat. It is important to know what is going on in the background of your progress.

It is important to make a note if you change from the planned meal. This way if the result is either positive or negative, you can trace it back. You will know what extra calories you took or what important nutrition you missed.