There are three components for a simple diet plan. These include schedule, nutrition, and exercise.
This includes forming your diet schedule. Daily and weekly goals for what you want to achieve.
Forming the nutrition schedule for you to intake. This include caloric goals and food types.
Includes the daily and weekly workout routine and the length of routine.
A simple diet plan relies on these things to be successful. You really don't need to over-complicate a diet. You can find more on simple diet plans at Dietcount.