Eons ago, the first humans quickly learned that naturally sweet foods are never poisonous and therefore safe. Back then, these kinds of energy-dense foods were relatively rare. When early humans found one of these treats, the hedonic reward system encouraged them to keep eating. This kept our ancestors from starving.
But our hedonic appetites have turned on us. Hedonic eating is now being studied as one of the biggest drivers of obesity. That’s because modern society has become awash in easy-to-grab, highly processed foods that our pleasure-seeking brains compel us to eat.
Sweet foods, in particular, flood the brain with the chemical signal dopamine. Once triggered, people may seek them out over and over again for the jolt of pleasure they bring. Under this theory, a hankering for doughnuts could be as hard-wired as a craving for heroin or alcohol. Critically, just as our bodies don’t need addictive substances, they don’t need the extra calories in fried dough.
“The obesity epidemic has nothing to do with the need for calories,” says Michael Lowe, PhD, a professor of psychology at Drexel University in Philadelphia. He coined the term “hedonic hunger,” or the primal drive to consume anything delectable even if we aren’t physically hungry.
Instead, Lowe says, “it has everything to do with wanting more food and, from my perspective, the pleasure from certain foods, and the calories are just along for the ride.”
And those tasty triggers are everywhere. Ultra-processed foods such as soft drinks and fruit drinks, breads, breakfast cereals, chips, and frozen pizzas make up almost 60% of Americans’ daily calories. They’re an alchemy of sugar, salt, fats, artificial flavoring, color, and texture -- a precisely calibrated industrial recipe for temptation.
Once you pack on the pounds, any attempts to shed them usually backfire, says Kevin Hall, PhD, an expert on metabolism at the National Institutes of Health in Bethesda, MD. Hall calculates that about every 2-pound drop in weight ultimately saddles your waistline with a net hit of 130 more calories a day. Drop 10 pounds? That’s 650 more calories a day your body will prompt you to eat.
Your body claws back the lost weight -- and then some -- via two routes at the same time. It slows your resting energy burn so you need fewer calories while it also ramps up hunger hormones and turns down hormones that make us feel full. The net result? You want to eat more than before you slimmed down.
Today’s humans are “completely unprepared to deal with” the consequences of this biological math, Lowe says. “Our bodies are primarily just like they were 10,000 years ago when we were living in nature.”
While homeostatic hunger has a built-in cue to stop, hedonic eating is harder to control. With modern life nothing if not a buffet of high-calorie feasts, people like Angie Gibson must constantly wrestle with their runaway appetites.
“One of the things we have learned is that there often isn’t an off switch when we have more than we need, when we’re eating for pleasure,” Lowe says.
