Decoding the influence mechanism of restaurant plate waste behaviors in urban China

Highlights

• Taking leftovers home directly reduce plate waste, especially at large restaurants.

• Frugality concern significantly results in less plate waste at large restaurants.

• Higher-income levels lead to more plate waste directly and indirectly.

• Encouraging people to eat by small groups would reduce plate waste effectively.

• Raising awareness of health and environment would considerably reduce plate waste.

Abstract

Reducing food waste through consumer behavior modification is crucial, yet collecting representative and primary data for key consumer segments and identifying the primary influential factors remain challenging. In this study, we utilized structural equation modeling (SEM) and large-scale direct weighing-based food waste data to examine the influence mechanisms of plate waste behaviors in urban restaurants in China. Our findings revealed that the number of consumers sharing a table and income level were the most significant factors directly contributing to plate waste. Conversely, the frequency of taking leftovers home and frugality concerns directly reduced plate waste, especially in large restaurants or when dining with families. Notably, income level showed opposing effects on behavior in fast-food restaurants and large restaurants. These results offered valuable insights into effective policies for nudging consumer behavior change and reducing food waste in restaurants.

Introduction

In recent years, food waste and loss has emerged as a global challenge (Sánchez, 2022; Wang et al., 2021). The United Nations Environment Program (UNEP) reported that 931 million tonnes of food were wasted in 2019, which accounted for 17% of global food production and 8–10% of global greenhouse gas emissions (UNEP, 2021). According to the Food and Agriculture Organization of the United Nations (FAO), approximately one-third of global food production is wasted annually, amounting to 1.3 billion tons (FAO, 2013). In China, food waste and loss account for roughly a quarter of the worldwide total (Gustavsson, 2011). Xue et al. (2021) reported that, on average, around 27% of food produced for human consumption was wasted in China per year between 2014 and 2018. However, with China's food demand steadily increasing in recent years and projected to rise by 16–30% by 2050 (Zhao et al., 2021), ensuring food supply and safety has become a major challenge in the country (Lam et al., 2013).

In China, the environmental burden resulting from food waste is also a significant concern. Xue et al. (2021) estimated that China wastes around 34% of its total water usage and 30% of the average cropland area annually to produce wasted food. Additionally, the production of wasted food has various environmental consequences, including non-point source pollution and phosphate depletion (Li et al., 2020). Therefore, reducing food waste can be an effective strategy to tackle the resource scarcity and environmental harm in China.

The consumption phase of the food life cycle contributes significantly to food waste, accounting for up to 17% of the total waste generated in China. Notably, dining-out situations account for 76.5% of this waste (Xue et al., 2021), highlighting the urgent need to focus on reducing waste in restaurants. Wang et al. (2017) estimated that food waste in restaurants was around 93 g per capita per meal in 2015, which is approximately five times more than that generated in households (Song et al., 2018). Therefore, a practical starting point to reduce food waste in restaurants is to change people's plate waste behavior. To achieve this, it is essential to understand the underlying mechanisms that influence plate waste behaviors.

Previous studies on food waste in restaurants in China have primarily focused on estimating the quantity of food waste generated and its environmental consequences (Ogunmoroti et al., 2022). Xue et al. (2021) estimated China's total food waste and loss at the national level and found that out-of-home settings, such as restaurants and canteens, contributed to 46% of the country's food waste-related carbon footprint, amounting to 215.2 Mt per year. At the regional level, Wang et al. (2017) and Wang et al. (2018) used direct weighing methods to quantify plate waste in restaurants in China. Moreover, a field survey by Zhang et al. (2022) indicated that the per capita food waste at surveyed restaurants in four Chinese cities was 80.21 g per meal. In addition to regular restaurants, there are growing studies on plate waste at school canteens, which have improved our understanding of food waste quantification in China. For example, Liu et al. (2016) evaluated plate waste during lunch at middle schools in Beijing, while Wu et al. (2019) and Qian et al. (2021) quantified plate waste among university students in China. However, there is still a lack of research exploring the underlying mechanisms that influence plate waste behavior in restaurants in China.

Numerous studies conducted in other countries have aimed to uncover the mechanisms behind restaurant food waste behavior. Among the commonly used approaches in these studies is structural equation modeling (SEM), which can explain the connections between individual variables (Kurisu, 2015). For example, Kim et al. (2022) used SEM to investigate how environmental awareness, moral norm, ascribed responsibility, and self-efficacy affect food waste reduction intentions in South Korean restaurants. The Theory of Planned Behavior (TPB) has been frequently employed in research on food waste in restaurants (Aktas et al., 2018; Graham-Rowe et al., 2015; Stefan et al., 2013). According to the findings of these studies, personal attitudes and perceived behavioral control towards food waste can impact the intention to waste food in a restaurant, and having an intention to avoid food waste can lead to waste reduction (Blešić et al., 2021). Additionally, Coşkun and Yetkin Özbük (2020) discovered that factors like price consciousness and food taste can affect the TPB's predictive power. However, most of these studies relied on self-evaluation through questionnaires instead of accurate waste weighing. Furthermore, the TPB has been applied to restaurant food waste in China in only a few studies.

Current studies on the influencing mechanism of restaurant food waste behaviors in China have mainly focused on single correlation results, with basic demographic factors being the primary consideration. For example, Wu et al. (2019) developed a regression model to investigate the key factors influencing plate waste behaviors among university students. Their results showed that students with lower education levels and higher disposable incomes wasted significantly more food. Similarly, Qian et al. (2021) conducted a t-test and one-way ANOVA to identify important determinants influencing university students' food waste. Their findings revealed that waste amounts vary significantly based on gender, education, and economic levels. Additionally, Wang et al. (2017) demonstrated that the amount of food waste differs significantly among different sizes of restaurants and different purposes of meals in China. Zhang et al. (2022) also found that warm-color plates and restaurant decoration color can help reduce plate waste at restaurants in China. While these studies provided a useful overview of the correlations between single influencing factors and plate waste amounts, the influencing mechanism among multiple factors and their combined effects on food waste remain poorly explored in China. Furthermore, qualitative analysis based on interviews, such as that conducted by Filimonau et al. (2020), revealed possible influencing factors (e.g., menu and cooking skill), but it is unclear how these factors affect plate waste in China.

The purpose of this study is to fill the aforementioned knowledge gaps and investigate the underlying mechanisms that influence restaurant plate waste behaviors in urban China. We collected data from a field survey of weighing plate waste in restaurants located in four Chinese cities. To identify the critical factors of plate waste behaviors, we used a behavioral model analysis that incorporated TPB-related, demographic, and behavioral factors. With the recent publication of the Anti-Food Waste Law in April 2021 (NPCC, 2021), the Chinese government has emphasized the need for restaurant food waste reduction. However, specific strategies to implement the legislation are still lacking. Therefore, our study can provide a theoretical foundation to develop targeted interventions that encourage individuals to waste less food by identifying the essential determinants of food waste behaviors.