Our love of soft, sweet foods goes back even further than we imagined

This morning, as I sliced a ripe banana into a pillowy bowl of fresh yogurt, I wasn't just indifferently throwing together another breakfast. I was tapping into a hunger that stretches back to the time before humans were even human. And those gnawing cravings that I get for cake and ice cream? They started rumbling 30 million years ago.

A recent study on our early anthropoid ancestors published in the American Journal of Biological Anthropology offers compelling evidence on how we evolved to love soft, sweet foods — in particular the kind we could easily reach from our homes in the trees. Examining the dental evidence of early primates discovered in The Fayum Depression in the Western Desert of Egypt, researchers from New Zealand, Spain and the U.S. concluded that "Our ancestors took a long time to move away from a diet based on soft fruits," a predilection that may have in turn had an influence on everything from our ability to detect colors to our social behaviors. You can see the through line even now, in the way food companies know that we're still suckers for sweet and soft.

It's long been known that we humans engineered ourselves to seek sweet things. What's interesting about the new research is just how much further back our taste for sweetness goes, and how texture, not just flavor, played a role in shaping how we eat, evolve and survive. Let's look first at sweetness.

"Early primates evolved to crave fruits because these foods are high in calories and were healthy in the small amounts available to them," explains Gabrielle Yap, a senior writer at the food site Carnivore Style. This craving was an evolutionary advantage, helping our ancestors survive and pass on their genes." (We also evolved to seek fats, which helped protect our organs, preserve energy and keep us sated.) It's been an evolutionary love affair ever since.

Dr. Sumeet Kumar, a Ph.D. in genetics and founder of the genetics information business GenesWellness, picks up the story from there. "Sweet tastes signal the presence of energy-rich nutrients, which would have been crucial for survival. This explains why the sensation of eating sweet foods triggers the release of dopamine, a neurotransmitter associated with pleasure and reward, reinforcing a sense of well-being and satisfaction. Now," he continues, "the sweet tooth is deeply embedded in our genetic makeup. The evolution of sweet taste receptors highlights the biological reasons for our preference for sweetness." 

Sweetness also signals safety, especially for our offspring. "Bitterness is typically linked to compounds that are poisonous, and the taste perception helps children avoid consuming plant materials in nature that would otherwise cause intoxication," says Dr. Bryan Quoc Le, food scientist, food industry consultant, and author of the book "150 Food Science Questions Answered." "This is an important taste feature for children especially, because their small size makes them more likely to die from smaller concentrations of toxins." 

We also seek out softness. For our fruit-loving forerunners a few million years before we figured out cooking, a little squish was an easy cue that our food was ready to eat. It also signaled that the food was a whole lot easier to consume. A 2022 New York Times feature on the science of chewing noted that "because chewing tougher food . . . takes significantly more energy, findings suggest that the metabolic costs of chewing may have played an important role in our evolution."

And when you combine soft and sweet, you get a great evolutionary bet. "Sweet, soft foods are typically associated with easy digestion and calories that can be rapidly absorbed or stored," explains Quoc Le. "For example, an unripe, hardened banana contains a high concentration of resistant starches, which is very difficult for humans to break down. However, ripened bananas are soft in texture due to their higher concentration of sugars and easier for humans to chew."

He adds that "foods with high concentrations of sugars and fats tend to be softer, which allowed early humans to take advantage of very energy-dense foods that were not difficult to break down."

Millenia later, sugar, fat and softness are still the comfort food jackpot. A 2017 study in the International Journal of Gastronomy and Food Science described the common denominator in what we consider comfort foods by noting that "on average they tend to be soft, smooth, sweet, and possibly have a salty/umami taste." A 2014 study by on how textures affect caloric intake by University of South Florida marketing professor Dipayan Biswas seemed to reinforce that notion. In one experiment, participants who'd been given soft, chewy brownies put away considerably more than those who'd been given harder ones.

We may have evolved to seek soft, sweet things, but we also evolved ourselves out of the trees and into the Costco. Most of us don't spend our days hunting and gathering, so we don't need to eat to like we do — even if the pull is still strong. "For most of history, humans lived in a state of food scarcity," says Dr. Christen Cupples Cooper, the founder of Pace University’s MS in Nutrition and Dietetics Program. "Food was hard to come by, requiring immense amounts of time and energy. It’s likely that sweet foods were attractive to the human palate because they provided a high calorie content and therefore, energy to sustain life." She notes that "The problem is that today, not only do we still like the taste of sweet foods, but we have considerably easy access to them and they are largely affordable. Many sweet foods people consume are not fruit hanging on trees in nature, but rather processed foods enhanced with added sugars and other chemicals that may pose harm to our bodies. Historically speaking, sweet foods have served us well at times — and have been detrimental at others." 

So why have some of us evolved to find sweet, soft things easier to resist than others do? Why do some people go all in on that box of strawberry donuts, while others seem to be take or leave them? Again, it's evolutionary.

"There is great genetic diversity in terms of the number of sweet receptors found both on the human tongue and inside the gastrointestinal tract," says Dr. Bryan Quoc Le. "These receptors help signal to the brain that there is a high concentration of readily available calories. Higher number of sweet receptors can help humans identify foods that would provide an energy advantage; humans that did not possess as many sweet receptors may not have been able to identify these excellent sources of food as easily." He says, "That difference in human sensory perception persists with us today." I'd like to take this as a verification that my love of pudding as a testament to the resourcefulness of my ancient ancestors.

"The human craving for sweet and soft foods is a complex trait," concludes Dr. Sumeet Kumar, shaped by millions of years of evolution, designed to optimize energy intake and survival." And now, he says, it still manifests in us, "as a source of comfort and joy."