Throughout human history, humans have artificially selected food. The sweeter, the better. When agriculture came into being, such genetic engineering became commonplace. A banana we eat today has nothing in common with one of a few hundred years ago. At one time we couldn't consume corn at all.

That evolutionary legacy, we once didn't have confidence when our next meal might be, is still evident. Sweet foods sell well and science has made them affordable; so affordable we have the opposite of the starvation problem poor people faced in the past.

Yet there may be too much of a good thing, finds an analysis of data created by an open-source data science site. It examined 393,568 unique food reviews of 67,553 products posted by 256,043 Amazon customers over a 10-year period and used statistical modeling to identify words related to taste, texture, odor, spiciness, cost, health, and customer service.

The authors computed the number of reviews that mentioned each of these categories and found a focus on product over-sweetness. Almost one percent of product reviews, regardless of food type, used the phrase "too sweet." When looking at reviews that referred to sweet taste, the researchers found that over-sweetness was mentioned 25 times more than under-sweetness.  Over 30 percent of the Amazon food product reviews mentioned "taste," making it the most frequently-used word.  Drilling down, the scientists found that sweet taste was mentioned in 11 percent of product reviews, almost three times more often than bitter. Saltiness was rarely mentioned, odd in light of government concerns about excess salt consumption.

The authors also looked at responses to the 10 products that received the widest range of ratings, as defined by the variability in the number of stars the product received. They identified two factors that tended to account for polarizing reviews related to a product: product reformulation and differing perspectives on the product's taste. With regard to taste, people often rated the sweetness of a product differently. Response to a product's smell also contributed to differences in opinion about a particular product.

"Genetic differences in taste or olfactory receptor sensitivity may help account for the extreme reactions that some products get," says Danielle Reed, PhD, a geneticist at Monell. "Looking at the responses to polarizing foods could be a way to increase understanding of the biology of personal differences in food choice."