text: why is the sweet flavor so good? why do humans (and other animals) perceive the sweet flavor as pleasant? sweet tastes good because sweetness in fruit is an indicator of ripeness, and ripe fruit is the most nutritious.  so, once upon a time, a sweet tooth was an evolutionary advantage -- those who enjoyed sweetness sought out the most ripe fruit and had the healthiest diets.  with healthier diets, they survived the longest and passed their genes on to the most offspring.   ironic.  our appreciation for sugar is actually rooted in good nutrition.  today, we have extracted sugar from fruit, and for a human being it is no longer conducive to a healthy diet.  in fact, our craving for sugar now has the opposite effect.