The pen and paper diet earned its name by the fact that it requires that you keep your diet details written in detail. To make this diet easy and manageable, invest in a large notebook and pen that you can use to plan out your meals, calculate calories, and keep track of your progress. For example, use a certain section of the notebook to add up your daily totals in calories. In another section, you can plan out how many calories you'll eat in different phases of your diet. A calculator is also recommended for the pen and paper diet to keep things precise and accurate.