SNi: Modelling the future of our food 


We all need certain nutrients in the right amounts to survive and thrive – how can we ensure everybody gets the nutrients they need in a sustainable way?

This is the big question that the Sustainable Nutrition Institute is helping to answer.

Professor Warren McNabb, Professor of Nutritional Sciences, SNi

What is the Sustainable Nutrition Institute?

The Sustainable Nutrition Institute (SNi) is hosted by the Ridddet Institute at Massey University, New Zealand’s premier national centre for scientific research in food. The SNi team is led by Professor Warren McNabb, with contributions from Dr Nick Smith and many other nutrition scientists, food scientists, and mathematical modellers.

SNi collaborates with universities and research institutes worldwide and provides research and expertise to the Food and Agriculture Organisation of the United Nations (FAO). SNi has been involved in publishing a dozen scientific papers on the global food system, particularly on its 
DELTA model. DELTA quantifies the nutrient requirements of the global population, compares that to the food the world produces, and then shows the shortfalls. This allows researchers to test scenarios for feeding the world and see what the consequences might be.

The SNi team has also developed the Nutrient Trade Model, which tracks how foods and nutrients flow between countries. There are several further models in development, including the iOTA model which optimises sustainable diets, and the NZ Model which explores future scenarios for New Zealand.

One of SNi’s aims is to develop realistic ways to provide the world’s nutritional needs in a sustainable manner, says Professor McNabb: “How do we create a diet that’s more sustainable, where we are better off nutritionally, but that doesn’t require a big change to the way we eat? This is a really difficult area to take the research and make it practical.”

Milk is more than protein and calcium; it has a whole bunch of other nutrients. There is no sustainable nutritional future that doesn’t have milk in it, because it’s so nutrient dense.

Professor Warren McNabb, Professor of Nutritional Sciences, SNi

Micronutrient deficiencies are surprisingly widespread

SNi thinks about food in terms of its nutrients and how to get everybody in the world the nutrients they need. A lack of vitamins and minerals can quickly occur when food is scarce. Nutritional deficiencies remain widespread in low-income and middle-income countries, particularly across South Asia and sub-Saharan Africa.

However, nutritional deficiency is surprisingly common even in relatively wealthy nations. For example, researchers have found that: 

For those in low-income countries, micronutrient deficiency is often caused by a lack of food and malnutrition. In contrast, people in high-income countries may have plenty of food available and sufficient calories in their diet, but the type of foods they choose to eat may still leave them at risk of nutrient deficiencies. 

Because it is so widespread, and not always obvious, micronutrient deficiency is sometimes known as ‘hidden hunger’. 

“Micronutrient deficiency will occur in high-income countries if we’re not eating the right collection of foods to give us adequate nutrition,” explains McNabb. “It’s part of modern life. Those easy-to-consume snack-type foods are often nutrient poor. Many ultra-processed foods are high in sugar and salt, but low in most other useful nutrients, so if they make up a high proportion of your diet, that won’t be adequate to meet your needs.”

Global food trade is vital to feeding the world  

How do we address global nutrient inadequacy? 

“An important part of this is trade,” McNabb says. “We have a lot of data on food trade, but very little on the trade of nutrients, so our Nutrient Trade Model enables us to investigate that.”

Internationally, improved distribution of nutrients could shift the dial on micronutrient deficiencies. A 2023 study by SNi found that depending heavily on trade makes a county’s food supply vulnerable to disruption by pandemics, wars, natural disasters and other crises. The Nutrient Trade Model app helps policy makers identify weaknesses in the global food system and which shocks might have the biggest impact on nutrition. 

In every country, inequality, economics, and human behaviour each have big roles to play in eating patterns, making micronutrient deficiencies a complex problem with no easy solutions. Here in Aotearoa New Zealand, we face our own challenges, and we rely heavily on trade, particularly with Australia which supplies the bulk of our wheat. A national food strategy would be one positive step toward improved food security, according to McNabb. 

“The New Zealand trade model is interesting – we import enough calories to feed twice our population. Why do we do that? All that rice and pasta! Where is it all going? We need to understand the nutrients New Zealanders require so we think about what foods we produce and import – are our diets adequately balanced and broad enough to meet our needs?” 

Many New Zealanders could benefit from consuming more milk

At an individual level, McNabb would like to see Kiwis eat a wide and varied diet. 

“And if anybody wanted to make a change to their diet and expect a benefit, they could drink a cup of milk a day – very few people drink that,” says McNabb. “Milk is more than protein and calcium; it has a whole bunch of other nutrients. There is no sustainable nutritional future that doesn’t have milk in it, because it’s so nutrient dense.”  

Widely available, nutrient dense and traditional throughout many cultures, milk and dairy products are not easily replaced in the global food system. Alternatives tend to have lower micronutrient density, are less widely available and can be much more expensive.

“It’s really hard, on a global level, to make diets that feed the world without milk,” McNabb says. “If you take milk out it’s quite difficult to get foods in there that replace the role of milk.”

The work being done by Warren and the team at SNi has already shone a light on the role of milk in the global food system. It is also helping advance human knowledge on nutrition and trade, while illustrating the complexity of creating realistic, sustainable food systems for everyone. We’re proud supporters of SNi, and its research is integral to shaping new policies that can reduce food inequality and fight malnutrition around the world.