As animals have evolved, the tastes that provide the most energy (sugar and fats) are the most pleasant to eat while others, such as bitter, are not enjoyable.
Kai gyvūnai evoliucionavo, skoniai, kurie duoda daugiausiai energijos (cukrus ir riebalai) tapo labiau malonūs, kai kiti, pvz., kartūs yra neskanūs.