This page allows you to track how much you're eating, eg a calorie counter.
In the Dates section you can view and create records for any day.
In the Entry section you can list and add the foods you have eaten for that entry. The Food field will auto complete the food name you are typing if we know it. If it is known, then the calorie information will be filled out for you (using a typical serving size). You can adjust the amount eaten and/or the calories before saving the changes. (The calories is really the important part here)