Sustainable eating: how to eat a healthy, eco-friendly diet

It’s the same issue for many New Zealanders. In Consumer NZ’s Sentiment Tracker, the cost of living was the number one concern for 56% of respondents. More than two-thirds (68%) said the cost of food and groceries was one of their top three financial concerns.

In an ideal world, we’d be able to eat a healthy diet that’s good for the planet, without breaking the bank. Is it possible?

Does food waste matter?

We shouldn’t underestimate the impact of food waste when it comes to saving money and reducing our emissions. A 2022 report by the Office of the Prime Minister’s Chief Science Advisor on food waste in Aotearoa said combatting food waste can deliver environmental, social and economic benefits.

In a 2018 household food waste study undertaken by Love Food Hate Waste, 52.8% (around 157,000 tonnes per year) was avoidable, with bread and leftovers topping the list. The study estimated the average household could save more than $600 per year by eliminating food waste.

This saving is likely to be conservative – it doesn’t take into consideration food waste sent to disposal units, compost bins and worm farms. A 2022 survey of New Zealand food waste estimated the average Kiwi household wastes more than $1500 worth of food each year.

Top 10 foods we’re wasting:

1. Bread
2. Leftovers
3. Oranges and mandarins
4. Apples
5. Bananas
6. Potatoes
7. Poultry
8. Rice
9. Lettuce
10. Beef

Source: New Zealand Food Waste Audits prepared for WasteMINZ, 2018.

The impact of food waste hits a lot more than our back pocket. When food is produced, processed, packaged, transported, stored and cooked, it uses resources. If food is wasted, that environmental toll is still felt without delivering nutrition. According to 2011 data from the Food and Agricultural Organization of the United Nations, if food waste was a country, it would be the third-highest emitter of greenhouse gases after China and the United States.

Māori health researcher and co-chair of Health Coalition Aotearoa’s (HCA’s) Food Policy Expert Panel associate professor Lisa Te Morenga said managing food waste also represents an opportunity to feed people.

“In the 2020/21 New Zealand Health Survey, 12% of children live in households where food sometimes runs out and 3% in households where food runs out often. This burden of food insecurity falls unevenly on Māori and Pacific families and socioeconomically deprived households.”

Dr Te Morenga said food rescue organisations do a great job managing surplus food and alleviating hunger, but they aren’t the solution to food insecurity or food waste.

Our top three tips for minimising food waste:

• Plan your shop. Prepare a meal plan and check the fridge before you shop. Make a shopping list and stick to it. If you don’t, you’ll be tempted to add extra items into your trolley.
• Store your food properly. Our storage tips give you the best advice for storing your food in the fridge or pantry. This can make a big difference to how long your food lasts.
• Know the difference between use-by and best-before dates on food. Check out our use-by dates on food article for more information.

Will changing my diet make a difference to climate change?

Slashing meat and dairy reduces the emissions from our diets, but this can hit our back pocket. In May, we reported on a New Zealand study that compared the costs and climate impact of four diets (with different scenarios). It found a vegan diet had the lowest average climate impact but came at a cost – more than $200 per fortnight for a family of four, compared with the current Kiwi diet.

Dr Nick Smith from the Riddet Institute’s Sustainable Nutrition Initiative at Massey University said if price trumps climate when buying food, consumers can be reassured that even making small changes such as following healthy eating guidelines can have a positive impact over a lifetime. Also, diet is just one way we can reduce our greenhouse impact, he said.

In a 2021 study published in Sustainability, researchers calculated what the cumulative global warming impact would be for the current average New Zealand diet over the lifetime of a person (rather than the shorter-term impact) and compared it with a diet that followed national dietary guidelines and a vegetarian diet (no meat).

“Like other studies, we found dietary changes made a difference,” Dr Smith said. “Following the dietary guidelines from the age of 25 reduced the cumulative warming associated with food consumption by 7-9% at the 100th year compared with the current diet, which includes more processed foods and less fruit and vegetables.

“The reduction by substituting meat was higher (12-15%). But when other activities such as transport, which is the largest contributor to household emissions, are taken into account, the warming reduction in both diets would be significantly less.”

Is eating local better?

There are a lot of reasons to buy and eat local food. It supports New Zealand businesses, many of which are smaller producers; it helps us buy in-season (when the food tastes best); and it can reduce the food miles of our diet if we’re not buying food that has been shipped or air-freighted from the other side of the world.

However, it’s not that simple. A 2020 paper published by Manaaki Whenua – Landcare Research into New Zealand’s food security stated it’s reasonable to assume we can produce sufficient meat, dairy and eggs for our local (and export markets), but there are certain foods that either aren’t grown here, or we don’t produce enough to meet domestic demand.

When it comes to getting our 5+ a day, we grow enough of most vegetables. A study published in Earth in 2021 concluded we grow the equivalent of 11.7 servings of vegetables per day per person. The largest quantities were potatoes, onions, carrots and squash (but most of these were exported). However, there was inadequate production of peas and beans and dark green, leafy vegetables.

It's a similar story for fruit. We grow enough apples and kiwifruit, but we import oranges and pears to meet out-of-season demand. Other fruit, such as bananas and pineapple, are mostly imported because we only grow low quantities here.

Some grain crops (mainly wheat and barley) are grown in New Zealand, but we don’t produce enough to meet all our demand for bread and cereals. The majority of our wheat comes from Australia.

Dr Smith said we need to consider what happens to our nutrient intake if we eat only local food. The Sustainable Nutrition Initiative investigated which countries produce sufficient quantities of nutrients to meet population requirements.

“We found most countries overproduce some nutrients compared to their requirements, such as protein in New Zealand, but underproduce other nutrients. “Only four out of 170 countries in our analysis were self-sufficient.”

Dr Smith said food trade – or nutrient trade – goes some way to balancing this.

There are also food groups we eat in large quantities that we need to import, including sugar, rice and coffee.

Dr Te Morenga said imported food gives us more food choices and variety, and imported staples such as rice are important, affordable food sources for many families.

“There’s also the social aspect of some of the foods we rely on as imports,” she said. “For many, drinking coffee is an integral part of the day. But, from a health perspective, cutting back on sugar and other nutrient-poor imported foods wouldn’t be a bad thing.”

Professor of nutrition at Auckland University of Technology Elaine Rush agrees. A study she co-authored in 2020 published in the European Journal of Clinical Nutrition found many high-nutrient foods produced in New Zealand such as dairy, fruits and protein foods are exported for income. On the other hand, imported foods included a large proportion of nutrient-poor foods including refined wheat, rice and sugar. Most of the grain we grow in Aotearoa is used for animal feed.

“A diet dominated by these foods is associated with nutrition-related diseases such as obesity, heart disease and cancers.”

Professor Rush said an environmentally sustainable and diverse vegetable supply for New Zealanders needs to be actively protected.

In 2021, The Aotearoa Circle’s Mana Kai initiative was developed. Professor of population nutrition and global health at the University of Auckland and member of Mana Kai’s leadership group Boyd Swinburn said the initiative recognises the wake-up calls that our food system is failing:

• the proportion of children living without healthy, affordable food;
• unsustainable rates of adult and childhood obesity;
• polluted waterways;
• lack of market competition.

“Mana Kai has developed a framework for New Zealand’s food system from growers and producers to consumers,” Swinburn said. “We’ll be producing a national food roadmap to enhance and protect our food system, taking into account a Māori view. This will enable us to identify solutions to help solve Aotearoa’s food challenges.”

Why is food so unaffordable in Aotearoa?

The price of the weekly shop continues to rise. While the disrupted supply chain, high petrol prices and overseas export prices have been partly blamed, it’s our unfair supermarket sector that plays the starring role.

The Commerce Commission inquiry into the supermarket sector confirmed what we’ve been saying for years: Our supermarket duopoly is not working for consumers. The inquiry found supermarket profitability is high (every day the major supermarkets are making profits in excess of $1 million), Kiwi consumers are paying more for groceries than overseas consumers, and pricing, promotional and loyalty practices are limiting consumers’ ability to make informed choices.

Public health dietitian and member of HCA’s Food Policy Expert Panel Leanne Young said high grocery prices under the current system result in many families struggling to afford food.

“Food insecurity affects children’s nutrition, with children in food-insecure households more likely to eat less fruit and vegetables (missing out on important vitamins, minerals and fibre), more fast food and fizzy drinks, and consume other cheaper, less healthy foods,” Dr Young said.

Dr Te Morenga agrees we can’t rely on the current market to provide us with healthy, affordable food.

“The Government intervened when the price of fuel got too high, but with food we’ve had a lengthy review, yet the duopoly remains intact. The supermarket industry needs to be urgently fixed, and the Government needs a national nutrition and food sovereignty strategy, instead of leaving our food supply to chance and market forces.”

Consumer NZ called for 10 fixes to the supermarket industry. Some of our recommendations are under way, such as the recent announcement of a Grocery Commissioner and consultation on the introduction of mandatory unit pricing. In August, the Government announced it will ensure the duopoly will open up wholesale access to groceries.

We support these changes but for consumers, real change at the till will take time.

Find out more about our supermarkets campaign.

How can I eat healthily during a cost-of-living crisis?

Sacrificing nutrition for cost doesn’t have to be a given when we’re planning what we eat.

A New Zealand study published in 2021 calculated the composition of a nutritionally adequate dietary pattern at the lowest cost. The cheapest diet cost $3.23 per day and included both animal foods (milk, mussels and eggs) and plant-based foods. Eliminating all animal foods increased the cost to $4.34.

Dr Smith said food products sourced from plants have the potential to supply sufficient nutrients, but the higher amounts needed to supply nutrients may be impractical and unaffordable.

“People also need to consider the nutrient bioavailability of foods, such as the higher iron bioavailability in animal products.”

Dr Te Morenga said most people would benefit from eating less animal protein, but she believes going completely plant-based is unrealistic for most people.

“There’s lots of ways we can eat healthily on a budget by shopping smarter, though,” she said. “Buying frozen and canned vegetables are often cheaper and don’t compromise on nutrition; milk powder can be used instead of milk in baking; and frozen meat is often cheaper than fresh.”

Dr Te Morenga’s top three tips for eating well through the cost-of-living crisis:

• Buy frozen. Frozen fruits and vegetables can save you money without compromising on nutritional value. Frozen meat is often cheaper, but avoid highly processed options such as chicken nuggets.
• Buy canned. Canned vegetables such as beans, tomatoes and lentils are great for bulking out a meal and are often on special so you can stock up. Canned fish, such as tuna and salmon, are an affordable protein source.
• Consider cheaper alternatives. Use milk powder instead of milk in baking. Buy cheaper cuts of meat. Cook them in your slow cooker and add extra canned vegetables or lentils and you’ll have enough for leftovers the next day.