A goal might be - lose weight! But a system might be - batch cook steamed veg with some healthy condiments, and eat that only during the day by having it always within reach.
By having a system for preparing easy, health food, you compound the effect instead of having a seemingly impossible intimidating goal that you keep putting off.
Other stuff that resonated with me were doing things that keep your personal energy as high as possible, stacking skills (be in the top 25 percentile at multiple things), and the idea that your brain is a moist computer that you can actually program in a desirable direction. The book really resonated with me.