The global food systems are currently responsible for about one-third of the stresses on the global climate and the overall health of our planet. From production over processing to consumption, the systems are not sustainable. Drastic changes have to be implemented to feed a growing global population a healthy, nutritious, and sustainable diet, but no food can be considered sustainable unless it is eaten. This brings taste and flavor into the picture. If we are to consume more plant-based foods and less meat, we must understand which fundamental driving forces are in effect when controlling our eating behavior. In this paper, I will argue that the biology of plants and the evolution of humans present a conflict when it comes to our genetically determined taste preferences. At the core of the argument lies that whereas food and flavor preferences are generally determined by cultural, social, and other behavioral factors, our craving for sweet and umami is a universal human trait. Via this argument, I propose that the umamification of plant-based foods is a key to promoting a more sustainable eating behavior.