How and where you shop has a direct impact on how much food you waste, according to new research on the sustainability practices of Irish householders when it comes to food.

The study by researchers at University College Cork (UCC) found that people who are members of Community Supported Agriculture (CSA) schemes (a membership-based system in which people pay towards production costs and receive food in return) waste less food than people who do their main food shopping at supermarkets.

“They are more engaged in the purchasing process and even though the food is more expensive, they waste less because they plan and think about how to use the food they buy,” says Prof Mary McCarthy, the lead researcher and professor of marketing at the Cork University Business School in UCC.

People who shop on the internet – using an online speciality foods platform or using a supermarket online system – are also less likely to waste food because they plan ahead. “When you shop online from home, you have time to look in your cupboards and see what you have. If you buy something impulsively, you can take it out again and you can be more structured about meal planning and healthy eating when you shop online,” says McCarthy.

For the study (which is part of a wider European research project on sustainable food production and consumption, SUSFOOD2), researchers interviewed 42 householders in their homes, dividing them up into those who bought most of their food in CSA schemes, those who purchased mainly from an online platform of specialist producers and suppliers or online from supermarkets, and those who usually did their food shopping in supermarkets.

“We had a sneaky peek inside people’s homes. We looked inside their cupboards, took photographs of their bins and they chatted to us about their food purchases and shared their frustrations and challenges around sustainability,” says McCarthy.

Acknowledging that members of CSA schemes are a niche group who regularly preserve or freeze excess food and share recipes and food with other members, McCarthy says that supermarkets – where 90 per cent of food is purchased – could still encourage shoppers to waste less food by following their example.

“Supermarkets could highlight and promote seasonal products and suggest meal concepts around local seasonal vegetables. They could give weekly tips on how to use something differently or how to extend the shelf life of perishable foods.”

Global tally

Globally more than one-quarter of all food produced is wasted. In Ireland, the Environmental Protection Agency (EPA), which runs campaigns to stop food waste (stopfoodwaste.ie), states that an average Irish household bins between €400 and €1,000 worth of food each year. Bread, vegetables, fruit and salad are the most common types of food that are thrown out and food dates are the main reasons why people say they throw out food. (Most food is still edible after its best before date but perishable foods should be eaten or frozen by their use-by dates.)

The Government’s Climate Action Plan and Waste Action Plan for a Circular Economy aim to reduce food waste by half by 2030 while encouraging householders to compost the remaining waste in their brown bins.

Giving people the opportunity to buy fresh fruit and vegetables loose rather than packaged is another way to allow customers control the amount they buy, therefore leaving them less likely to overpurchase and see some of the food go to waste.

Researchers from UCC also suggest that supermarkets could train more staff to become sustainability ambassadors or encourage interaction between producers and chefs via pop-up stands demonstrating and sharing recipes and preservation techniques for local, seasonal produce.

‘Coffins of decay’

The study makes references too to the so-called “coffins of decay” that are areas of our fridges and freezers where food is forgotten and left to go bad. “We leave leftovers like rice or pasta in the fridge but if we don’t have a plan for its use, it’s left there until we appease our guilt for wasting it and then throw it out when it has gone mouldy,” says McCarthy.

Ironically, she says that because most of us navigate our food practices within busy lives, those who try to transition to more sustainable food purchasing practices such as vegetable box schemes or farmers’ markets might not always reduce their food waste.

“Changing household practices is challenging and although you might be motivated to buy and use food differently, your attempts can be frustrated by not knowing how to cook certain vegetables or not having all the ingredients for a dish. So you go ahead and do what you normally do and the week has passed and the new vegetables are left unused.”

The researchers suggest supermarkets could offer customers who purchase €10 worth of local and seasonal fruit and vegetables €1-off vouchers for preservation aids such as food processors or dehydrators/dryers.

In weight terms, about 1 million tonnes of food is wasted in Ireland each year, which works out at about 150kg of food waste per household, or 80kg per person. Apart from the financial loss and ethical issues involved, food waste produces between 8 and 10 per cent of all global carbon emissions.

The amount of plastic packaging on food was another concern expressed by many of the householders interviewed by UCC researchers. “We have to move away from single-use plastic and towards the circular use of packaging,” says McCarthy. And while some supermarkets have started to replace plastic with cardboard on some foods, she suggests that greater incentives are needed to introduce refill and reuse for non-perishable foods such as cereals, pasta and rice.

“It has to be popularised first and then if supermarkets give a financial incentive such as a coupon or money off, it will build up over time.”