The Paper of the Month for February is ‘The development of sodium reduction targets for New Zealand fast foods and a comparison with the current sodium contents of products‘. The blog is written by author Shona Gomes, and the paper is published in the Journal of Nutritional Science.

Sodium in fast-food

Fast-food – it’s quick, convenient, and hyper-palatable. Part of its palatability comes from the generous amounts of added sodium [dietary salt]. For example, a hamburger with fries can easily provide more than a person’s daily upper limit for sodium of 2,000mg. Unfortunately, too much sodium is linked to high blood pressure which is associated with cardiovascular disease, the leading cause of preventable death in Aotearoa, New Zealand (NZ) and globally, and sales data shows our appetite for fast-food is increasing.

Sodium reformulation and targets

New Zealanders, like populations in most Western countries, get most of their dietary sodium (about three-quarters) from processed foods, including fast-foods. For this reason, the World Health Organization considers reformulation of sodium in processed foods, a “Best Buy” strategy for reducing sodium in people’s diets. If done gradually, consumers don’t notice the lower amount of sodium in their food.

To drive companies to reformulate, countries taking serious action have developed sodium reduction targets. While there are national targets for some processed supermarket foods in NZ, no such targets exist for the fast-food sector. Directly copying the targets from another country is not a solution as there can be big inter-country differences in the sodium content of fast-foods and there is no published data on how to develop sodium reformulation targets for fast-food. This study describes the development of maximum sodium reduction targets for NZ fast-foods and compares these with the current sodium content of products.

Target development

We analysed the sodium content and serving size data from an existing database of major NZ fast-food chains in 2020. Targets were developed following a step-by-step process, informed by international targets and serving sizes, and previous methods used for supermarket targets. Sodium reduction targets were set using a 40% reduction in the mean sodium content or, if that was too strict, the value met by 35-45% of products. Sodium reduction targets were developed both:

• Per 100 g, to reduce the sodium concentration of products.
• Per serving, to ensure any reduction in sodium concentration is not ‘undone’ by increases in serving size (a concerning trend).

Results

Sodium reduction targets were developed for 17 categories of fast-food. Overall, there is considerable room for sodium reduction in NZ fast-foods. The low availability of nutritional information for fast-foods (only one-third of products in the database had sodium data) will be a major barrier to developing sodium reduction targets and monitoring their impact.

What next?

NZ needs a broad national sodium reduction strategy implemented by government. Our methods outline one aspect, a step-by-step process for the development of feasible, yet impactful country-specific sodium reduction targets per 100 g and serving for fast-foods. Fast-food companies should be required to provide nutritional information (including sodium) to monitor sodium levels in foods, assess the outcomes of reformulation, and help consumers make informed choices.

Each month a paper is selected by one of the Editors of the six Nutrition Society Publications (British Journal of Nutrition, Public Health Nutrition, Nutrition Research Reviews, Proceedings of the Nutrition Society, Journal of Nutritional Science and Gut Microbiome). Take a look at the entire Nutrition Society Paper of the Month Collection.