• Plant and Food Research reports –

With growing shifts in people diets, changes in consumption patterns and more awareness about climate concerns of food production, there are increasing conversations about consumers and their food sustainability choices.

However, in these conversations’ nutrition is not always considered. There is little data about the relationship between nutrition and environmental impacts. For example, how do nutritionally dense foods with higher environmental impacts compare with nutritionally inadequate foods with low environmental impacts?

A group of scientists from Plant & Food Research and Massey University are bringing the climate impacts of nutrition into the conversation. They recently published a paper comparing different popular New Zealand toast toppings in a nutritional Life Cycle Assessment (nLCA) – an evaluation tool comparing a foods nutritional value with its environmental impact.

By using toppings-on-toast sized portions, they based this study in a meal context meaning these foods were evaluated in a real-world situation using everyday New Zealand consumer eating patterns. They wanted to explore a metric for assessing the climate impact by nutritional density of foods.

“Many nLCA studies compare foods on an equal weight e.g. what impact does producing 100 grams of each food have on the climate” explains Dr Carolyn Lister, one of the leads on this project.

“But in a meal context you don’t eat the same weights of each food. Plus, not all foods give the same nutritional benefits. You could have a food that was good environmentally for a certain weight, but if nutritionally it was underdelivering and you had to eat 10 times the amount to get your required level of nutrition, then you change those environmental impacts considerably.”

From a survey of NZ consumers favourite foods to put on toast, 14 foods were selected: avocado, tomatoes, cheddar cheese, salmon, tuna, chicken, egg, butter, mushrooms, banana, honey, jam, nut butters, and bacon. A serving size portion of each of these toppings i.e. how much would be eaten if it were on toast, was evaluated for its climate change impacts and different nutritional values using data from previous literature and the New Zealand Food Composition Database.

The study found that avocado and peanut butter topped the lists, while bacon, butter and cheese were the lowest ranks.

While there could be potential variability in the climate impacts or nutrition data used, this study lays the groundwork for future research into this area and a method for providing information to help support consumers.

“This study is about trying to build an understanding of what data is needed for people to make more informed decisions about their food choices and their diets. With a scale like this, we can let the consumer decide based on their own diets and environmental concerns, what they are willing to prioritise or sacrifice when it comes to food and their own health.”

Journal reference:

Majumdar S, McLaren SJ, van der Pols JC and Lister CE (2024) An nLCA approach to support consumer meal decisions: a New Zealand case study of toppings on toast. Front. Sustain. Food Syst. 8:1363565. doi: 10.3389/fsufs.2024.1363565

Source:  Plant and Food Research