Research: Defining junk food

An analysis examining three decades of food policies by US researchers from NYU and Tufts University has aimed to define ‘junk food’ and determine which foods should be subject to health-related policies, combining food category, processing and nutrients to determine the results. Junk food is typically used to define snacks and desserts with low nutritional value, a category that makes up 15% of all calories consumed in the US.

One policy that requires a definition for junk food is a junk food tax, which raises the price of such products to reduce consumption. Several countries have successfully implemented this tax, each defining junk food differently. Hungary, for example, taxes unhealthy food that falls into certain categories and have elevated levels of nutrients, such as sugar and salt — an approach that has led to lower consumption of junk food and increased awareness about nutrition, and which has nudged manufacturers to reformulate their products to make them healthier.

Researchers evaluated policies where federal, state or tribal governments defined categories of food for taxation or other regulatory purposes to gain a deeper understanding of what constitutes junk food. They identified and analysed 47 laws and bills from 1991 through 2021, including one active junk food tax law implemented by the Navajo Nation, three state snack food sales taxes that were later repealed and numerous junk food tax bills that have not been enacted.

They found that existing policies used several criteria to define foods, including product categories, processing, place of preparation or sale, nutrients and serving size. Of the 47 policies, 26 used multiple criteria to define foods.

Two themes emerged: first, policies used categories of food products to help differentiate between necessary or staple foods and non-staple foods. For instance, bread was often excluded from junk or snack food policies, as it is widely considered a staple food, while sweets and chips were considered non-staple foods.

Second, policies commonly added a combination of processing and/or nutrient criteria to further determine which products within food categories would be subject to or exempt from regulation, generally favouring products with lower levels of processing and additives.

The researchers concluded that their analysis supports the use of junk food taxes implemented as excise taxes to be paid by manufacturers or distributors. Revenue from these taxes may then be used to improve access to healthy foods.

“An advantage of excise taxes is that food companies may be motivated to reformulate their products to be healthier to avoid taxation,” said study co-author Sean Cash. “Defining foods to be taxed is not a static exercise, as existing products are reformulated and thousands of new packaged foods are introduced each year — so how we tax foods is not just a tool for steering consumers away from the least healthy options, but also for encouraging healthy innovations in what ends up on the supermarket shelves.”

Image credit: iStock.com/LauriPatterson