Have you ever wondered why unhealthy foods taste so good? Human taste buds seem to favor foods that are high in fat, salt, and sugars, but doesn't it seem like it should be the other way around? You may be surprised to find that the answer to why unhealthy foods taste so good is because they are actually good for us and our taste buds evolved to react favorably to them! But before you go and eat an entire gallon of ice cream in the name of health, let me explain what I mean by this.
The earliest humans got quite a bit more exercise than your average human today, and their diet was largely plant-based and scarce in fats, sugars, and salt, which are necessary for survival. Carbohydrates and sugars are required for energy, while fats are necessary for long-term storage of energy. The sodium from salt is used to regulate the balance of fluids in the body. The pleasurable tastes associated with these substances evolved as a reward system so our ancestors would seek out these foods. This is why foods that we now consider unhealthy taste good.
Foods rich in fats, sugars, and salt are in much greater supply in today's world than they were back then. Seeking out these foods is no longer a matter of life or death, it has just become too much of a good thing. Humans today also lead a much more sedentary lifestyle than their ancestors from before the days of T.V., video games, and the internet, which makes excess calories even less important to the modern diet.
Our natural evolutionary tendency to favor high-energy foods, combined with our decreased need for calories and increased availability of such foods is what has led to the recent obesity epidemic. Ironically, the same mechanism that ensured the health and survival of the human race is now causing one of the biggest public health concerns for the developed world.