Photos of pricey pre-cut avocados and $8 bottles of water garnished with asparagus have attracted a lot of attention online, adding to the perception that healthy food costs more than processed alternatives.

But a new study from the U.K.-based Institute of Economic Affairs comparing the costs of groceries pound for pound suggests bills don’t add up as quickly when shoppers fill their carts with more nutritious foods.

Researchers found a wide range of fruit, vegetables and carbohydrates are available at less than $3.29 per kilogram. By contrast, the majority of less healthy products, such as frozen meals, chocolate, chips and bacon, cost more than $4.93 per kilogram. Prices were taken from two leading British supermarkets in November 2016.

“Starchy carbohydrates, rice and potatoes, plus vegetables, really are very cheap,” author Christopher Snowden told CTV News Channel on Sunday. “It has really been the peasant diet for hundreds of years around the world.”

Previous research on the subject of “food efficiency” has often relied on analysing items on a cost-per-calorie basis when a better approach would be to compare typical servings of food by weigh or portion size, he says.

Snowden argues the long-standing theory that many low-income individuals and families lack the financial resources to put healthy food on the table does not add up. He notes that other factors that disproportionately impact these groups, such as time at home, could be to blame.

“The reason I think people are not eating as much fruit and veg as they should has little to do with prices,” he said. “It’s down to not having the right cooking skills, (and) not having the right time.”

An exception to the rule

The study, titled Cheap as Chips: Is a healthy diet affordable?, notes that meat and fish are often the exception to the rule.

White meat was found to be significantly cheaper than red meat, but processed meat tended to be cheaper than fresh fillets. The report also cites research which found leaner cuts are typically more expensive than fattier ones.

Snowden says unhealthy diets are often the result of consumers shopping with their taste buds instead of the wallets.

“It seems that U.K. consumers are prepared to pay more for taste and convenience, ,” he wrote in his report. “Neither price nor nutritional quality are necessarily considered paramount by food shoppers.