This excerpt from "Grain Brain" by David Perlmutter and Kristin Loberg presents a compelling argument against the modern, high-carbohydrate, low-fat diet, claiming that it contributes to various health issues, including brain disorders. The authors contend that inflammation, often triggered by gluten and excessive carbohydrates, is a key factor in brain degeneration. They advocate for a low-carbohydrate, high-fat diet rich in healthy fats, arguing that this approach can improve cognitive function, boost energy levels, and even enhance sexual performance. The book provides detailed information about the potential negative effects of gluten and sugar, as well as the benefits of a ketogenic diet and specific brain-boosting supplements. It concludes with a four-week program designed to help readers transition to a healthier lifestyle.