Americans tend to associate our health problems with sin. It’s hard to find a health story in the news that doesn’t blame greed and lack of willpower for our ongoing epidemics of obesity and diabetes as well as a recent upturn in the rate of heart disease. But the problems stem more from a greedy food industry than from any weakness in consumers. Our supermarket shelves are filled with items made with cheap ingredients, especially sugar and corn syrup, whether people want it or not.

A fascinating new study out of the Monell Chemical Senses Center in Philadelphia showed that among 400,000 food reviews on Amazon.com, the primary complaint was that food was too sweet. People used terms like “syrupy, overwhelmingly or cloyingly sweet,” said behavioral geneticist Danielle Reed, who led the research. She and her colleagues used a machine-learning program to sort through the thousands of reviews covering 67,553 products.

The finding was a surprise; she had designed the study to add to her body of work on the way people vary in the perception of bitterness. Genetic differences make some people much more sensitive to bitter tastes than others, and this can affect whether we love or hate vegetables such as broccoli and kale. She was surprised, she said, that on Amazon reviews, consumers rarely complained about bitterness, or saltiness for that matter. They complained about sweetness. Manufacturers may think they are sweetening things to suit a common taste, in which case they are getting it wrong – but the market is full of oversweetened foods, so the manufacturers mostly don’t lose customers to better-tasting competitors.

Or the problem may be that manufacturers are trying to use the cheapest possible ingredients in a way that consumers will still tolerate. Sugar is cheap, and corn syrup even cheaper. In his book “The Omnivore’s Dilemma,” author Michael Pollan recounts the way the introduction of corn syrup in the late 20th century tempted manufacturers to add as much as possible to many processed foods and to lure consumers with giant sodas and other supersized products that felt like bargains but came with hidden costs. Later, the medical dogma that fat was deadly led to an explosion of extremely sweet low-fat products as well.

However we got here, it’s clear that the empty calories are contributing to epidemics of obesity in the U.S. and elsewhere. The food police should rethink chastising consumers and turn their attention on the true culprits who are dishing it out.