What are better foods according to the author?

Directions: Read the passage and answer the following question.

Self control is the ability to say no, in the face of temptation, and to take sustained action, despite the difficulty of a given challenge. At its heart, self-control requires the ability to delay gratification. More commonly, it’s called discipline, or will. Without self-control, we can’t accomplish almost anything of enduring value. And we rarely pay much attention to it.
Over the past decade, I’ve built a company, The Energy Project, which is devoted to helping people and organisations improve sustainable performance, in a large part by more systematically exercising self-control. Over the years, we’ve learned that nearly everything people tend to believe about self-control is wrong. Most of us assume the only way to resist our impulses, or persevere under pressure, is to grit our teeth, furrow our brows, steel our nerves, and tough it out. Precisely the opposite is true.
Energy is the fuel for self-control. We each have one reservoir of energy to get things done. Each act that requires self-control progressively depletes this energy reservoir, whether it’s when you use it to resist a piece of cake, or focus single-mindedly on a difficult problem, or stay calm when you feel provoked.
Eating strategically is the most fundamental way to increase the energy we have available for self-control. Eating more frequently — five to six times a day — provides us with regular doses of glucose, which is the body’s primary source of energy. It serves us best to eat low-glycemic foods, such as lean proteins and complex carbohydrates, which provide a more sustaining source of energy than sugars and simple carbohydrate.