You’re at a barbeque, the sun on your shoulders, surrounded by family and friends and delicious smells from the grill. On the picnic table in front of you, a summer feast: corn, potato salad, burgers. Bright triangles of juicy watermelon, latticed pies bubbling with fresh fruit. You sit on the grass to eat lunch under a canopy of leaves. At the end of your meal, you turn toward dessert, blueberry cobbler topped with vanilla ice cream. As you bring the perfect, sweet spoonful toward your mouth, something happens inside your body and brain. What exactly is this feeling?

Monica Dus, associate professor of molecular, cellular, and developmental biology at LSA, has the answer. “Our bodies love sugar!” she laughs. “It’s chronicled in our genes because of evolution. Sugar has a lot of calories, which means it has a lot of energy, so it’s really important and rewarding for us to eat. Evolution wired us to be able to tell that there is energy in sugary food by allowing us to recognize sweetness.

“We feel a lot of pleasure when we eat sugar because that’s one way evolution ensures we get to the thing we need to do. Evolutionarily speaking, we need to eat enough calories to survive, so food tastes good to ensure that we do that, especially when it comes to sugar.”

Dus explains that sugar has a major effect on us before we even take the first bite. She says that our memories—of previous sweet treats, of happy memories associated with eating them—can get activated just by sight and smell. And when we taste the ice cream or cake or peach, the pleasure of the sweetness and other flavors lead the brain to make new memories.

Then the metabolic effects begin. Sugar, fat, and protein are processed from the mouth to the gut, which sends nutrients directly to the brain. Once broken down, the food goes into the body and provides nutrients to cells. Blood sugar goes up and then falls once the cells eat up all the sugar. It’s also nourishment for organisms that live in our gut and process the food we eat, breaking it down into molecules that feed the microbiome. In short: it’s complicated.

“In that one bite that lasts a second, there is a whole history of many species and many processes,” Dus says. 

Sugar High, Sugar Medium, Sugar Low 

We all know sugar’s reputation: the cravings, the rush, the crash, the addictiveness. But when it comes to embracing the joys of summer, do we really need to be wary?

For Dus, it depends.  

Sugar found in fruit follows the same process in our bodies as that in ice cream, almost. “The major difference is that sugar in processed foods comes in a form that our bodies absorb really fast and really well,” she explains. “Sugar that is naturally occurring, like in watermelon or dates, has other nutrients like fiber that have to be broken down before being metabolized, which slow absorption. The sugar high and crash aren’t as intense.” 

According to Dus, it’s not sugar per se, but that we end of consuming more than the recommended amount. But, she says, we shouldn’t blame this on our favorite summer treats.

“When we’re having ice cream or watermelon or lemonade, we know we’re eating sugar because we chose it. The problem is when we end up eating a lot of sugar without knowing it. Those hidden and added sugars are in 70 percent of the foods at a grocery store, foods that aren’t even meant to be sweet, like pasta, bread, and yogurt. Those are the things we should we paying attention to.”

So enjoy your dessert when you’re at the barbeque. Take a bite of the blueberry cobbler, the sweetness hitting your tongue and teeth, and be happy that summer isn’t over yet.