Consumers consistently judge food with shorter expiry dates as healthier and more natural, even when the only difference between products is their packaging, according to research published in the Journal of Consumer Psychology.
Scientists from the University of British Columbia in Canada, alongside colleagues from Jinan University and Hainan University in China, examined how shelf life influences shoppers’ perceptions and purchasing decisions, according to Bankier.pl.
In one experiment, participants compared potato crisps with five-month and nine-month use-by dates. The overwhelming majority rated the shorter-dated crisps as healthier and more natural, whilst they viewed the longer-lasting product as better for the environment and more effective at reducing food waste.
Packaging trumps ingredients in shoppers’ minds
The research team tested whether highlighting different values would shift purchasing patterns. When participants had to choose between pasta sauce with a one-year or three-year shelf life, nearly 70 per cent selected the shorter-dated option when researchers emphasised eating natural food. When environmental protection was stressed instead, that figure dropped to 43 per cent.
Remarkably, shoppers continued to associate shorter shelf life with naturalness even after being explicitly told that longer storage periods resulted solely from better packaging rather than processing methods. In a mayonnaise experiment, participants were shown different versions and informed that the variation in durability came exclusively from more airtight containers. Despite this clear explanation, those prioritising natural products still chose the shorter-dated mayonnaise more frequently.
A similar pattern emerged with cereal bars. Though two presented products had nearly identical ingredients and nutritional values, study participants more often judged the one with a briefer use-by date as healthier.
Mental shortcuts drive poor choices
“Packaging contains all the information needed to make a rational choice: ingredient lists and nutritional values. But processing all that requires effort,” explained co-author Dr Yann Cornil. He noted that most people prefer relying on simple cues like expiry dates, packaging type or advertising style during routine shopping trips.
The researchers acknowledged that highly processed foods often do carry longer shelf lives. However, they stressed that greater durability doesn’t always indicate higher processing levels. Contemporary packaging technologies can significantly extend shelf life without substantially altering product composition.
According to the study authors, consumers use expiry dates as a mental shortcut to quickly assess whether a product is natural, rather than analysing all available information. This tendency could be driving unnecessary food waste.
“In seeking out natural food, consumers tend to choose products with shorter use-by dates, even though longer-dated ones might be equally good, healthy and natural, and wouldn’t need throwing away so often,” Dr Cornil said.
He also pointed out that shoppers don’t always correctly understand food durability labelling and often discard items that remain perfectly safe to eat.
What this means for Poles in the UK
British households waste an estimated £14 billion worth of food annually, with confusion over date labels contributing significantly to the problem. Understanding the difference between “use by” (a safety deadline) and “best before” (a quality indicator) can help reduce unnecessary waste and save money on your weekly shop.
When buying groceries, check ingredient lists and nutritional information rather than relying solely on expiry dates to judge food quality. Products with longer shelf lives aren’t automatically less healthy – modern packaging simply keeps them fresh longer. This is particularly relevant for Polish shoppers who may buy speciality items less frequently or send food parcels to family in Poland.
Before discarding food past its “best before” date, use your senses – many products remain safe and tasty well beyond this advisory deadline. Only “use by” dates on perishable items like meat and dairy represent genuine safety concerns. Adopting these habits can cut your food bills whilst reducing environmental impact.
