1. Introduction
“There is growing evidence of success in reducing food waste […]. Much more can be done. We need, for example, to address the role of consumer behaviour, in all cultural contexts […]. Let us all shop carefully, cook creatively and make wasting food anywhere socially unacceptable while we strive to provide healthy, sustainable diets to all.” (Inger Andersen executive director of the United Nations Environment Programme [
1]).
Reducing food waste has emerged as a priority for the United Nations [
1], which have adopted a specific target in the recently published Sustainable Development Goals (SDGs) to halve global food waste per capita at the retail and consumer levels by 2030 (SDG 12, Responsible consumption and production, Target 12.3). Reducing food waste contributes to two general objectives [
2]: (i) improving global food security (SDG 2, zero hunger), and (ii) reducing the environmental footprint associated with food that is wasted (SDG 6, clean water and sanitation, SDG 13, climate action, SDG 14, life below water, SDG 15, life on land).
According to the most recent estimates, around 931 million tonnes of food are wasted each year [
1], while between 720 and 811 million people in the world face hunger every day [
3], representing an actual “food paradox”. In such a context, tackling food waste is deemed to be one of the most effective ways to decrease pressures on the food system and to contribute towards enhanced food and nutrition security [
1,
2,
4].
Wasting food also means wasting resources used for its production. The food system is resource intensive and accounts for 70% of freshwater withdrawals, 38% of land resources, and approximately 30% of energy consumption [
5,
6]. Therefore, better food waste management could help to solve some environmental sustainability issues related to the global food system, potentially reducing its water, land, ecological, and energy footprint [
7]. Food waste also contributes to global greenhouse gas emissions and represents an obstacle to cope with climate change [
8,
9]. According to Mohareb et al. [
10], meeting the 12.3 target could reduce 11% of the total CO
2 emissions per capita.
In the last decade, research on food waste, mainly household food waste, has exponentially increased [
11,
12]. Households are mainly responsible for food waste, accounting for 61% of the total food waste (nearly 570 million tonnes/year); therefore, they have the highest potential to prevent food waste [
1]. Scholars have dedicated their efforts to quantifying food waste and looking for its determinants (socio-demographic features, as well as psycho-social and cultural factors) to better understand the phenomenon and to identify mitigation strategies [
13,
14,
15,
16,
17,
18]. Recently, significant attention has been given to food management behaviours (FMBs) other than food waste behaviour (FWB) [
19,
20,
21,
22,
23,
24,
25]. As highlighted by Quested et al. [
26], food waste is the result of multiple behaviours, such as planning, shopping, storage, preparation, and consumption of food. As immediate drivers of food waste outcomes [
24], understanding such FMBs is crucial to designing and implementing actions to prevent food waste.
Households’ FMBs that affect food waste have been investigated in different countries, such as Australia [
22], Germany [
24], Greece [
23], Italy [
25], and the UK [
20], and similar results have been reached with few differences due to country-specific eating habits and diets. Among the different FMBs, shopping and preparation (e.g., leftovers use) emerge as the most crucial for food waste outcomes in all countries.
Several socio-demographic factors, such as family size and composition, age, and income, have also been related to food management and waste behaviour. Comparing different generational groups (baby boomers, Generation X, Generation Y, and Generation Z), Karunasena et al. [
22] found that younger generations tended to waste more food due to a lack of food management skills, especially cooking skills. Their findings were in line with other works in which age and food waste have been found to be negatively related [
26,
27,
28,
29]. At the same time, their findings contrast with other studies, highlighting how young people are more concerned about food waste and its environmental and financial impacts [
30,
31]. Whether or not young people are culpable in wasting food more than older people, they remain to be an interesting group to focus on; as future generations of parents, leaders, and citizens, young people might potentially solve food sustainability issues and other matters arising from food waste [
32,
33]. Understanding youth behaviour and acting on it now represent an opportunity for the future of food system sustainability.
Even though research on the drivers of youth food waste is growing in frequency [
22,
27,
28,
33,
34,
35,
36], it remains relatively scarce compared with other studies on youth pro-environmental behaviours (e.g., pro-environmental purchase intention towards eco-friendly apparel, energy saving vehicles, and healthy food) (e.g., [
37]). In particular, the roles of the cognitive, emotional, and behavioural aspects that influence youth FMBs and food waste have been empirically investigated by only a few studies [
34,
35,
36]. This lack of studies has limited our understanding of youth behaviour and our ability to identify interventions to prevent food waste and to promote sustainable management of food chains. Based on the above and with the necessity to develop interventions coherent with all specific cultural contexts [
1], this study aims to investigate factors affecting the food waste of younger generations in Italy. Specifically, this study extends the theoretically grounded framework of the theory of planned behaviour (TPB) [
38] to explain and to predict the FMBs of Italian youths who belong to Generation Y and Generation Z. Several studies have demonstrated that adding factors to the TPB model, such as personal norms and environmental concern, could help to increase its predictive power in explaining people’s intentions to conduct pro-environmental behaviours. Moreover, these factors could assume different roles and relevance according to age. Therefore, we applied an extended TPB model to answer two main questions. Which factor (or factors) has (have) the most effect on intention and food waste reduction behaviours? Do differences across generations exist in the way cognitive and psychological aspects relate to food waste behaviour? Answering these questions can help to identify evidence-based actions for fostering sustainable food waste management systems. This paper is structured as follows:
Section 2 introduces the theoretical background supporting the research hypotheses,
Section 3 describes the methodology, the results are presented in
Section 4, and discussion and conclusions are provided in
Section 5 and
Section 6, respectively.
5. Discussion
The results support the main relationship suggested by Ajzen’s TPB model with respect to food waste behaviour. Coherently with the base TPB model, attitude and PBC are antecedents of the intention to not waste food and intention is able to predict the actual behaviours. These findings are in line with similar studies [
51,
65,
66,
67,
68]. With respect to previous studies, our work aimed to estimate how the relevance of these factors varied with age. Previous studies that have focused on food waste have mainly dealt with age as characterising different behavioural profiles or analysed its relationship with food management behaviours (e.g., [
15,
18,
28,
49]). Some other studies have applied the TPB model to young people as a specific age group [
34,
35,
36]. The novelty of our work is that we studied the differences within young generations by applying two distinct TPB models for Generation Y and Generaton Z, which better highlighted the differences across generations in the nature and strength of the links between the constructs of the behavioural model and also allowed for suggesting more focused and targeted interventions.
Concerning the relevance of antecedents in influencing intention, the data results, firstly, show that, for Generation Z, attitude has the largest direct association with the intention to reduce food waste, while the relationship between PBC and intention is very low. On the contrary, the influence of PBC on intention is the most relevant in the Generation Y model. Therefore, in younger people, the intention not to waste food is mainly affected by the thought of food waste as something bad, while for young adults, their perception of having control of the food waste is the most relevant antecedent of intention.
A second consideration concerns the influence of subjective norms on the intention to not waste food. In the TPB base model, an individual’s perception of the expectations and opinions of others about their own behaviour shapes the intention to behave in a certain way. Previous studies on food waste behaviour generally found that the subjective Norms weakly affect the intentions, and that was partly ascribed to its poor measure and the need for a better specification of the normative component [
69]. In the present work, including personal norms in the base model responded to this last need. The data results support our expectation that personal norms mediate the effect of social norms on intention, and the findings are in line with similar studies on household waste recycling [
45] and other environmentally relevant behaviours [
70]. Moreover, our results indicate a high and significant relationship between personal norms and the intention to not waste food. They are consistent with previous studies such as those by Werf et al. [
54], Nigbur et al. [
45], and Visschers et al. [
42]. In our work, the use of two distinct models also highlights that the links between social and personal norms, as well as between personal norms and intention, are different across Generation Y and Generation Z. Personal norms are highly related to social norms (both DSN and ISN) in the Generation Z model, while the link is small and limited to DSN in the Generation Y model. Then, in younger people, personal norms are influenced by what significant others think the person ought to do and what significant others do themselves, and subjective norms are relevant in the formation of PN. Social pressure plays a less important role in young adults, but personal values are still affected by behaviours within one’s specific social context.
A third aspect deals with the role of environmental concern. In this study, the model was extended to consider environmental concern as a factor affecting all antecedents of intention. Awareness of environmental issues is a relevant factor acting on all antecedents, but the intensity of the relationships varies across generations. In particular, environmental concern has a higher influence on Generation Z norms; it affects personal norms directly and indirectly through social norms, and norms reflect on the intention to reduce food waste. As far as Generation Y is concerned, environmental concern mainly acts on the perceived behavioural control and personal norms. In contrast, the effects on the social norms are less and limited to injunctive subjective norms. Therefore, in line with previous results [
46,
47], knowledge of the environmental issues and their consequences represent a key factor to address pro-environmental behaviours, but our work highlights that the mechanisms through which this awareness translates into food waste reduction behaviours are rather different according to an individual’s age.
6. Conclusions
The analysis of the food waste behaviour of Generation Y and Generation Z using two distinct TPB models highlighted how the factors affecting food waste intention and behaviours differ across young Italians. Moreover, including personal norms and environmental concern in the base TPB model widened the research perspective providing further insights and suggestions for preventing food waste.
The findings of this study suggest various research and intervention implications.
The present work underlined the relevance of personal norms in influencing the intention to not waste food and the different relationships between personal norms and social norms according to age. According to Schwartz [
41], personal norms are integrated into one’s values. Bamberg [
46] and Shi et al. [
71] considered personal norms to be the individual internalization of social pressure. Therefore, from a research point of view, the different relationships between social and personal norms across generations calls for a deeper knowledge of how experience, social context, and socialization processes act during personal growth and maturation. Moreover, knowledge about how personal norms form, change, and are activated could be helpful to define which factors to act on at the different growth stages of an individual and for the design of social interventions to promote food waste reduction behaviours.
From an operative perspective, the results of this work provide some suggestions to define interventions aimed at changing FW behaviour. In Generation Z, personal norms are highly explained within the model by environmental concern and social norms. Moreover, environmental concern has a strong effect on social norms and attitude. Therefore, educational programs aimed at increasing knowledge about environmental issues related to food waste and awareness-raising campaigns represent relevant instruments to address young people’s behaviours toward preventing food waste and promote sustainable management of food chains. They can affect the social context that conditions younger generations and contribute to forming the personal norms that inspire their actions. Educational campaigns could be less effective as age increases. In young adults, personal norms continue to be a direct predictor of the intention to reduce FW but are more structured, less dependent on the social context, and less explained by TPB constructs. In Generation Y, the role of PBC is higher, and interventions to address intention and behaviours toward reducing FW should mainly increase skills and provide instructions to improve food waste management.
This study has some limitations. Firstly, the sample is not representative. We used a convenience sample based on self-selection, and that implies a self-selection bias. Nevertheless, the results are helpful to provide insights into food waste behaviours across young generations and represent a starting point for further investigations. A second limitation could be related to using the English language in the questionnaire. The survey was aimed to collect data from different countries, even if the present work focused on young Italians. The use of English might have led to misinterpretations of the statements. However, the participants volunteered to be involved; therefore, we expected that only participants who understood English should have answered the questions.