Sugar is the main ingredient of most sweet tasting food. The surface of the tongue has special sensors called “taste buds” that detect sugar and other things in foods. When any type of sugar touches the tongue, taste buds send a signal to the brain. Then the brain reacts in a way that we feel as pleasure. Scientists think the brain’s reaction is a reward for eating the foods we need.
Why would the body reward us for eating sugars? Doctors tell us to limit the amount of sweet foods we eat because too many sweets can lead to obesity and sickness. But sugar also contains energy that our bodies use, and we need sugar to survive. Thousands of years ago, when people hunted and gathered wild foods to live, very sweet foods were rare and hard to find. But these foods were healthy in the small amounts found naturally. The body rewarded people for searching long and hard for sweet foods, such as fruit.
After people learned to grow the plants and raise the animals they needed for food, sweets became much easier to find. Today, it is rare to find a packaged food that does not have extra sugar added. As a result, many of us eat so much sugar that it can harm our health.