At first, the Diary doesn't have to be extremely detailed. At this point, it is more important just to get into the habit of recording what and how much we eat. Eventually, more information will be added because, as with anything else, the more effort that is put into something, the greater the reward. That said, at the very beginning, its best to keep it very simple.
Starting Out ...
Begin by initially only recording the name and quantity of the food or beverage and the time of day that you ate or drank it. Make sure to note the state of the food. In other words, was it raw, baked, sauteed, grilled or deep-fried? If your not sure about the exact quantity or it is not possible to measure it (like at a restaurant), you can estimate. It is, however, important to try to estimate correctly. Here is a great article on estimating portion sizes when you can't measure: Use Your Hand to Estimate Portions And, here is an infographic containing a simple chart illustrating a "portion" of various foods, including meat, dairy, fruits, vegetables, snacks and condiments.
And, here is a great infographic showing what 200 calories of various foods "looks like")
Adding Some Basic Information ...
Once you begin learning about food nutrition, you can add certain basic information to your Diary entries. You can also then go back and fill in this information for previous entries. This basic (but all important) information consists of the approximate amounts or equivalents of the following nutritional content in each food and beverage:
Belly Fat: Food Diary (Part 1)