You get bored of a taste after a couple of bites, which causes you to eat a wider variety of foods.

When you take your first bite of a beautiful, tasty food, the flavor explodes in your mouth and you may think to yourself, “Ah, you know, this eating ability we have is pretty good.”

You take the second bite expecting the same zing of flavor, but you don’t get it. That bite doesn’t taste as good as the first.

And then you take the third bite and the same reduction in flavor happens. The more of a food you eat the less flavor you taste and the less pleasure you experience from eating. At the end of a large dish, it’s likely you taste almost nothing at all.

This effect is called sensory-specific satiety. Bite by bite, as you eat a food, your brain is dialing down your response to that food. Why would you brain do such a dastardly thing?

You become bored by the taste of a food so you’ll switch to another food. You see, the sensory-specific satiety effect works on the foods you have been eating recently. Switching to a new food brings back the full pleasantness, taste, smell, and pleasure of the new food. Switching to a new food also resets your hunger level so you feel hungry again, even though you may have eaten a lot already.

You can demonstrate this effect with a quick test using chewing gum. Chew a piece of gum until you stop noticing the flavor. Take the gum out of your mouth and put it somewhere safe. You’ll need it again. Where do you think the flavor went? Did the gum run out flavor? It didn’t go anywhere. The flavor is still there. Your brain turned the flavor off so you will switch to a new food. To prove this, wait about five minutes and start chewing the gum again. The flavor will magically reappear.

Why would your brain want you to switch foods so often? The wider the variety of foods you eat the better chance you have of meeting your nutritional and caloric needs.

Think back to what we said about why you taste particular flavors. Your brain can’t tell you what specific foods to eat because you have to eat from what’s available. Neither can your brain tell you what combination of foods to eat, so it tries to get you to eat as many different flavors as it can, on the bet that this will maximize your chances of getting all the nutrients you need.

As a result, humans have an incredibly varied diet. We eat a wider variety of foods than any other animal.

Now think what happens at a buffet! You have access to lots of different kinds of foods, many of them highly caloric. Poof! Your diet goes down the drain. This is an unconscious process you don’t even realize is going on.