4_restaurationCollectiveGaspillage
π Planet π Society
How to reduce food waste

Food: why do consumers waste food?

with Marina Julienne, Independent Journalist
On May 11th, 2022 |
3min reading time
Sandrine Costa
Sandrine Costa
Economist and Research Fellow at the MoISA* laboratory of INRAE
Key takeaways
  • Sandrine Costa studies food waste to suggest measures that can impact on consumer behaviour.
  • By studying the leftovers on trays of 479 people who had eaten in different company restaurants, she observed that while 398 of them had left food, only half of them said they had.
  • Collective catering is a strategic lever in the fight against waste. It has been estimated in various European countries that between 13 and 55% of the food produced and distributed in collective catering ends up in the bin.
  • Making a shopping list, learning how to cook leftovers, reserving a specific place in the fridge for leftovers so that each member of the family can spot them, can all be effective in avoiding waste.

Why have you directed, or co-directed, so many theses on food waste?

To pro­pose meas­ures that can have an impact on con­sumer beha­viour. If we hope to reduce food waste, it is essen­tial to under­stand why people waste in the first place. Are con­sumers aware or not that they are throw­ing away food? Does it make them feel uncom­fort­able or not? What are the indi­vidu­al, but also social or mater­i­al factors that influ­ence their beha­viour? These stud­ies take a long time to carry out, as they involve going to cater­ing facil­it­ies or canteens, and into fam­il­ies to observe what hap­pens there or to con­duct indi­vidu­al inter­views. We can­not always be sat­is­fied with declar­at­ive state­ments in response to ques­tion­naires. Not least because people tend to down­play waste­ful behaviour.

Doesn’t everyone have the same definition of waste?

Indeed, Maxime Sebbane, a lec­turer in mar­ket­ing at the Insti­tut Agro Mont­pel­li­er, has worked on col­lect­ive cater­ing and has shown to what extent the defin­i­tion of waste is not self-evid­ent. It depends in par­tic­u­lar on the quant­ity left (some people con­sider that leav­ing half a piece of bread is not waste­ful, where­as oth­ers will con­sider it to be), the qual­ity of the product left (a badly cooked veget­able will be con­sidered waste­ful or not) and even, more sur­pris­ingly, the nature of the product: for example, a per­son who leaves a dessert behind may con­sider that it is not waste­ful because it is bet­ter for his or her health not to eat too much sugar! 

Fur­ther­more, we found that many people deny their own waste habits. When we stud­ied the leftovers on the trays of 479 people who had eaten in dif­fer­ent com­pany res­taur­ants, we found that while 398 people had left food, only half of them said they had left any! 

Wasteful behaviour is not only dependent on individuals?

In the frame­work of a qual­it­at­ive research study con­duc­ted with Mar­got Dyen, lec­turer in mar­ket­ing at the Uni­ver­sity of Savoie Mont-Blanc and Lucie Sir­ie­ix, pro­fess­or in mar­ket­ing at the Agro Insti­tute of Mont­pel­li­er, we were inter­ested in what people do and say around the “Eat Smart” cam­paign and the “Anti-waste” cam­paign. Mar­got Dyen con­duc­ted inter­views and then went to the homes of the people inter­viewed to observe their prac­tices in their social and phys­ic­al envir­on­ment. Many of these prac­tices are based on com­plex cooper­a­tion and coordin­a­tion between dif­fer­ent people in the house­hold. When you must man­age the food pref­er­ences of sev­er­al people, the sched­ules of adults, chil­dren and teen­agers who do not eat at the same times, it is very com­plic­ated to avoid waste. For example, veget­ables bought to meet the “good nutri­tion” plan can end up in the bin…

What recommendations can be drawn from these studies?

In the cater­ing industry, our research has shown that an organ­isa­tion can clearly induce waste­ful beha­viour and/or foster a sense of ‘enti­tle­ment’ to waste. For example, char­ging a single price for a ‘starter-main’ or ‘course-dessert’ com­pon­ent does not encour­age diners to mod­u­late their choices accord­ing to their appet­ite, and a single size of con­tain­er does not encour­age them to mod­u­late quant­it­ies accord­ing to their appet­ite either.

We con­duc­ted an exper­i­ment with more than 200 par­ti­cipants by offer­ing con­sumers “small hun­ger” plates (21 cm in dia­met­er) or “large hun­ger” plates (24 cm in dia­met­er) for the main course, which allowed people to ask for a quant­ity adap­ted to their appet­ite, and for cooks to serve smal­ler quant­it­ies. This meas­ure, which is very simple to imple­ment, reduced the amount wasted by 20%.

It should be remembered that col­lect­ive cater­ing is a stra­tegic lever in the fight against waste. It has been estim­ated in vari­ous European coun­tries that between 13 and 55% of the food pro­duced and dis­trib­uted in col­lect­ive cater­ing ends up in the bin. In France, this sec­tor rep­res­ents nearly 3.6 bil­lion meals per year, which gen­er­ate 440,000 tonnes of waste – this rep­res­ents an eco­nom­ic loss of €910 mil­lion per year and 1.5 mil­lion tonnes of avoid­able green­house gases!

What can be done to reduce waste at home?

Mak­ing a shop­ping list, learn­ing how to cook leftovers, reserving a spe­cif­ic place in the fridge for leftovers so that each mem­ber of the fam­ily can find them, can all be effect­ive. More gen­er­ally, the research we con­duc­ted with Guil­laume Le Bor­gne, a seni­or lec­turer in mar­ket­ing at the Uni­ver­sity of Savoie Mont-Blanc, showed that indi­vidu­al aware­ness of waste had a more marked pos­it­ive effect on the adop­tion of “anti-waste” prac­tices than “glob­al” aware­ness. Clearly, com­mu­nic­a­tion cam­paigns that high­light the sav­ings that can be made by the house­hold by wast­ing less will be more effect­ive than cam­paigns that point out the neg­at­ive effects of waste on the envir­on­ment and waste man­age­ment. Finally, people who are made aware of “waste” from child­hood will waste much less than oth­ers, which argues for edu­ca­tion on this sub­ject from school onwards.

Support accurate information rooted in the scientific method.

Donate