Once you set up the diary, you enter in the foods you eat, along with
how many servings you ate, each day and it tells you
how many calories you consumed. You can set it up to keep track of the amount of fats, fiber, sugar, protein, etc.That lets know, at a glance, if you are staying within your calorie "budget", or if there are certain things you might be eating too much of, like fats or sugar. If you need help setting it up, I'll be glad to help.