Almost 800 million people are suffering from malnutrition in the world today. Meanwhile, around a third of all the food produced for human consumption is wasted or lost. This food waste, which amounts to around 1.3 billion tonnes every year, occurs at all stages of the food chain, from the farm to the consumer’s home, and its value is thought to be around US$1 trillion. As the world population continues to increase, reducing the amount of food that is lost or wasted will become more essential than ever. It has been estimated that by 2050 we will require a 60% increase in global food production to feed the population.
The causes of food waste differ between countries around the world. In developing countries, losses tend to occur at the earlier stage of the supply chain and are often due to financial and structural limitations in harvest techniques, storage and transport infrastructures, processing, cooling capabilities, packaging, marketing and infrastructure, as well as climatic conditions that favour food spoilage. Social and cultural conditions can also play a role in food loss in these countries. In medium- and high-income countries, meanwhile, waste tends to occur at the more downstream end of the food chain and often relates to food quality standards and consumer behaviour.
Not only does food waste have a negative impact on food security and global hunger - rich countries, by buying hundreds of millions of tonnes of food that ends up being wasted, remove food from the market, raising the demand for these commodities and making them less affordable for poorer nations - it also has detrimental effects on the environment. Without accounting for greenhouse gas emissions from land use change, the carbon footprint of food produced but not eaten is estimated to be 3.3 billion tonnes CO2 equivalent, making food wastage the 3rd top emitter after the USA and China. The produced but uneaten food also occupies almost 1.4 billion hectares of land – almost 30% of the world’s agricultural land area, and uses around 250 km3 of surface and groundwater resources. In addition, it represents a major threat to biodiversity worldwide.
So, why is so much waste occurring along the food chain, and what can be done to reduce it?
The date labelling conundrum
Confusion about date marking on packaged foods is one factor that leads many consumers to throw away food that would still be perfectly safe to eat. One particular problem is the assumption that these dates are all linked to food safety when, in fact, some are intended to inform consumers about the quality of the product instead, and some are not intended for consumers at all.
In Europe, two types of date mark addressed at consumers – “best before” and “use by” dates – can cause considerable confusion. While the “use by” date relates to food safety and is used on foods that are highly perishable and likely to constitute a danger to human health if eaten after that date, “best before” dates refer just to the quality of the food, and indicate the date until which a food product will retain its specific properties when properly stored. While the quality of a food product may decline after it has reached its “best before” date, it won’t necessarily become a health hazard and is likely to remain safe to eat for considerably longer. All too often, however, food that has not been eaten by the time the “best before” date arrives just ends up in the bin.
The presence of other dates on packaging, such as “sell by”, “display until”, “baked on” and “packed on” dates, intended to help retailers manage stock, only add to consumers’ confusion, while differing date regulations between countries don’t make matters any easier either.
Date labelling is far from the only factor leading consumers to waste food, though. Poor planning can cause some people to buy more than they need, while buying larger amounts of food less frequently makes it more likely that products will have spoiled by the time consumers go to eat them. Poor food preparation techniques, portion planning and knowledge on how to use leftovers can also contribute to food waste at the consumer level.
In addition, household demographics also play a role in how much food is wasted. A study in the International Journal of Consumer Studies looked at the influence of socio-demographic, behavioural and attitudinal factors on the amount to avoidable household food waste in 380 Finnish households. It found that only a few factors clearly correlate with the amount of avoidable food waste, which were size of the household, gender of the person mainly responsible for the grocery shopping, frequency of buying discounted food products, the respondent’s view of the potential to reduce food waste and the respondent’s view of the influence of purchasing particular food packet sizes.
The FAO report, Food losses and waste in the context of sustainable food systems, also reveals that household composition, income and culture can have an impact on the level of waste. While tendencies are quite variable, with national and regional differences, it appears that households with higher incomes tend to discard more, consistent with their greater food consumption, and a larger amount of food waste has been noted in households with a greater presence of young people and adolescents.
It seems though, that despite not always using up everything we buy, consumers are often reluctant to discard food and feel guilty when they do. The FAO report reveals that consumers often wait until food has reached its expiry date and keep food remaining from a meal in the fridge or freezer before discarding it, even if they know they probably won’t use it.
Piling up the produce
While better planning, purchasing habits and preparation techniques could solve some of these food waste issues, other reasons for food waste occurring in the home are more out of the consumer’s control. The amount of a product we buy, for example, is usually dictated by the pack size available in the shops. Even if a consumer only wants a small amount of a product, they might have to buy far more than they need if the product is only sold in larger amounts. And despite our best intentions, these extra products often seem to end up lurking at the back of the cupboard months later, growing older and older, and less and less likely to end up in our dinner.
Advertising campaigns, in-store promotions and bulk discounts also frequently prompt people to buy greater quantities of a product than they need, not to mention products they had no intention of buying in the first place. Products bought in offers like these make up a large and growing portion of the amount we spend on groceries, but often end up in the bin when we discover that we can’t, in fact, get through the 4 bags of oranges, 6 packs of sausages and 20 cream doughnuts we’ve been tempted to buy before they go off.
And while full shelves bursting with an abundance of products might look attractive to customers, and give the impression that the shop won’t run out of anything we might need – they wouldn’t want us to go elsewhere, after all, stocking up the supermarket shelves can lead to waste. The tendency for stores to frequently replenish their stock inevitably leads to products with different expiry dates being displayed at the same time. When this happens, consumers tend to ignore products with close-by expiry dates in favour of those that will last for longer, and the older products end up being left on the shelf, getting closer and closer to their expiry date.
The perfect appearance
Produce that is not “perfect” in terms of its colour, shape, size and freedom from blemishes is regularly rejected by retailers. The FAO’s “Reducing the Food Wastage Footprint” toolkit notes that farmers often have to discard between 20 and 40 percent of their fresh produce because it doesn’t meet the cosmetic specifications of retailers. This can lead farmers to grow more produce than is needed to make sure there will be enough to meet the strict cosmetic standards imposed by the supermarkets. The cancellation or reduction of forecast orders at the last minute can also leave growers and food processors with extra products and nobody to sell them to. According to the FAO toolkit, waste due to overproduction can reach up to 56% of a company’s total output, meaning more food is wasted than is sold.
One final cause of food waste at the retail level is the rejection of processed foods due to the “rule of the one-third”. This self-imposed practice proclaims that processed foods must reach the suppliers in up to one-third of their shelf life time, the main intention being to enable consumers to have a wide choice of fresh products that are relatively far from their expiration date. If products fail to be delivered by the first third of their shelf life, many retailers reject the delivery and return the items to the producers, leading to perfectly good food being discarded.
Back to the beginning of the chain
Further back in the supply chain, mistakes made, trimming of products and contamination during processing can all result in wastage, while a lack of capacity at facilities to cope with busy periods can also result in food being lost. Poor handling during packing and loading on and off transport, unsuitable choices of containers, poor ventilation, inappropriate transport conditions, a lack of infrastructure and delays during distribution can also lead to food being wasted.
More losses occur even further back in the chain due to products deteriorating, contamination, the greening or sprouting of root and tuber crops, and infestation and damage by pests. Improper drying, lack of knowledge about good post-harvesting handling techniques, and poor hygiene and sanitation standards during the initial post-harvest handling stages can also lead to losses, while poor harvesting techniques, premature or delayed harvesting, climatic conditions, soil conditions, choice of variety and agronomic practices all lead to food being lost before it has even reached the farm gate.
Tackling the waste
So what can be done to reduce all this waste? Among other possibilities, changes to planning and shopping routines could help consumers reduce waste. A study in Food Quality and Preference showed that these routines, determined by moral attitudes towards food waste and perceived behavioural control, are important predictors of food waste, and suggested that to change consumers’ food waste behaviour, efforts should be directed towards providing consumers with skills and tools to deal with their food-related activities.
A study in British Food Journal meanwhile, showed that the more aware the Italian university students taking part in the study were about food waste, the more likely they were to reduce leftovers, and a greater awareness of the consequences of wasting food also increased the likelihood of them making a shopping list.
In another study it was noted that over 630,000 tonnes of freezable food is estimated to be thrown away each year by consumers in the UK due to it having passed its “use by” date or because it is perceived to be spoilt, much of it could instead have been frozen to eat at a later date.
Improvements in food packaging could help reduce waste, too. An article in Food Engineering describes several packaging technologies that can help keep products fresher for longer, including modified atmosphere packaging, packaging materials that prevent light from reaching the product, microperforations in fruit packaging that let ethylene escape, and smart or intelligent labelling technology that can detect when a food has spoiled.
These are just a few of many possibilities that could help us reduce food waste along the food chain. But while some changes might be relatively easy to implement, certain causes of food waste could prove harder to resolve. Waste can occur at one level of the supply chain but have a cause at an earlier stage, while efforts to improve efficiency at one stage might be quashed if the waste still occurs later on. A lack of access to finance, particularly in developing countries, might also prevent some changes from being made, while policies, laws, and regulations could affect the ability and incentive for changes to be made.
With challenges occurring all the way from the farm to the fork, making the big reductions in food waste needed to improve food security and decrease the impact on the environment could be a complex task. But the importance of doing it is very clear, and we need to begin somewhere. So perhaps, as consumers, we could all start by trying to think of how, exactly, we are going to use up those left over Brussel’s sprouts this Christmas?
(Image Credit: BDJ123 at www.freeimages.com)
- Plant Waste May Find a Place at the Table
- Almost Half of the World's Food is Thrown Away...
- The Sustainable Food Packaging Revolution
At IFIS, we are passionate about food science and news. To receive our monthly Thought for Food blog posts, subscribe below: