Nutrition is the most important aspect of this. It is more important than exercise even. If you want goal is to lose weight, you need to know it will be impossible to out-train a bad diet. If want to prevent disease and live long, you need to know it is directly correlated to the quality of food you eat and toxins you avoid.
Chapter 1.1 Foundational Knowledge allows you to understand the meal plan and why the foods are there. Not only will you learn why this meal plan works, but you will also learn how to maintain and modify this for your entire life. You need to be able to learn how to go out and make your own food choices. How to eat at a restaurant. Understanding the core concepts of nutrition allows you to maintain any body weight you want for your entire life while being able to eat any food you choose. The most import aspect is that understanding the foundational knowledge allows you to go and teach other people this. When they ask a question, you will have an answer. When people see you change your life you become motivational to them and they will listen. Be able to give them correct information. You will learn about hydration, macronutrients, micronutrients, along with the laws of thermodynamics and how it applies to calories for weight loss.
Chapter 1.2 The Meal Plan allows you to learn how to maintain a body fat percentage you feel comfortable with. There are numerous fad and crash diets that exist out there. They are not sustainable and will result in what we call “yo-yo” dieting causing fluctuations in weight. You also do not need to ever go into a bulking phase to build muscle. A calorie surplus is not required for muscle building. You simply need a stimulus for growth (calisthenics), enough protein to fuel the growth, and water.