Because you don't have a steady stream of carbs to fuel your brain. Protein at meals helps time-release the carbs for steady energy rather than up and down spikes. If you're relying only on fleeting foods, such as crackers or bread, you'll only experience short bursts of mental energy, followed by the fog.
About SonarQube SonarQube is an open source platform to perform automatic reviews with static analysis of code to detect bugs, code smells and security vulnerabilities on 20+ programming languages including Java, C#, JavaScript, TypeScript, C/C++, COBOL and more.
It was Lewis Nixon who invented the very first sonar-type listening device in 1906. He was seeking a way of detecting icebergs. But the sonar was not invented, its inventor was nobody, but developed through the years. Sonar had very humble beginnings, from crude instruments to advanced technology.