Developing a Preliminary List of Indicators for Green Restaurants in Taiwan: An Expert Consensus Approach

Abstract

This study aims to develop a preliminary list of indicators suitable for green restaurants in Taiwan. The research methodology includes expert consensus (Delphi method) and incorporates interviews with field experts. An analysis of the responses provided by these industry experts led to the identification of five dimensions of evaluation indicators for green restaurants. The K–S test involves using a z-test on ordinal variables for single samples to determine whether the sample distribution diverges from the frequency distribution. This study analyzed the responses provided by the interviewed experts to identify and extract evaluation indicators for green restaurants. The extracted indicators comprise five dimensions (resource management, ingredient and product selection, environmental and indoor quality, green certification and management, and customer awareness and participation), 15 sub-dimensions, and 70 detailed indicators. The research results can serve as a reference for course planning in related programs at universities and colleges, as well as for industry planning of green restaurants, and as a reference for the promotion of national sustainable environmental policies in Taiwan. Therefore, based on the results of this study, recommendations are provided for educational institutions related to green restaurants, official organizations related to green restaurants, the industry related to green restaurants, and future researchers.

1. Introduction

As an emerging concept, green restaurants aim to reduce the environmental impact of the foodservice industry by minimizing their carbon footprint, using local and organic ingredients and reducing waste, while offering healthier and more sustainable dining options. Driven by the growing awareness of environmental protection and the Sustainable Development Goals (SDGs), green restaurants have gradually become a focal point for both consumers and the industry. However, there is still no unified standard or method for evaluating green restaurants globally. Most evaluations remain focused on food safety and hygiene, with relatively insufficient assessment of environmental impacts and social responsibility. Consumers increasingly need higher standards for food quality and sourcing. They are willing to support businesses and restaurants that actively promote sustainability and expect restaurants to not only ensure the taste and quality of food but also take on appropriate roles in environmental and social responsibility [1]. Despite the widespread popularity of the green restaurant concept, accurately evaluating and certifying whether a restaurant meets green standards remains a challenge. Mai et al. [2] explored green attributes and customer behavior to understand customer willingness to consume restaurants’ services.

The increasing awareness of environmental protection has garnered widespread attention. According to the UNEP [3] report, environmental issues worldwide are becoming increasingly severe, and promoting environmental protection has become a consensus across various industries. As major consumers of resources and producers of waste, the rise of green restaurants is a proactive response to these environmental challenges. Consumers’ needs for green restaurants are primarily reflected in the use of environmentally friendly materials, energy conservation, and waste management.

Although the rise of green restaurants is evident, there is currently a lack of unified and systematic evaluation indicators for green restaurants in Taiwan. Most existing [4,5,6] research focuses primarily on a single aspect of environmental measures, such as the use of organic ingredients or the reduction of single-use plastics in restaurants. While these studies provide valuable information, they fail to comprehensively cover the multidimensional performance of green restaurants. The lack of systematic evaluation indicators makes it difficult for consumers to accurately understand the actual environmental impact of green restaurants, and it also hinders the standardization and management of these establishments. Understanding consumers’ specific needs for green restaurants can not only help restaurants improve their environmental practices but also promote the healthy development of the market [7]. Maynard et al. [8] aimed to build an instrument classification adopting cutoff points from the sustainability assessment checklist validated for restaurants.

In summary, this study aims to establish scientifically grounded and reasonable evaluation indicators for green restaurants to promote the development and sustainability of the green restaurant industry. This will not only enhance the market competitiveness of green restaurants but also drive the entire foodservice industry toward a more sustainable development direction. The findings can serve as a reference for curriculum planning in college programs related to foodservice, the training of industry professionals, and certification of culinary technicians.

Based on the aforementioned research background and motivation, the objective of this study is as follows: establish scientifically grounded and reasonable green restaurant evaluation indicators. Through an in-depth literature review, expert interviews, and the Delphi method, we systematically collect and integrate theoretical and practical experiences regarding the evaluation of green restaurants. This results in the establishment of an evaluation framework that includes aspects such as environmental impact, social responsibility, and economic benefits. This will help to determine the impact and significance of the evaluation tools for both the industry and consumers in practical applications.

2. Literature Review

This study explores the relevant literature on green restaurants and the construction of evaluation indicators, with a focus on the current state of the foodservice industry in Taiwan for further exploration and research.

2.1. The Green Restaurant

Founded in 1990, the Green Restaurant Association (GRA) [9], an international nonprofit organization, has pioneered the Green Restaurant^® movement as the leading voice within the industry, encouraging restaurants to green their operations using transparent, science-based certification standards. The Green Restaurant Association’s standards reflect over 30 years of research in the field of restaurants and the environment. Including restaurant owners and customers, the GRA was started to increase awareness of the problem in the foodservice sector and encourage eateries to green their processes and practices [10]. As sustainability has become one of the most critical issues confronting the service industry, particularly the foodservice industry, the concept has gained greater significance [11,12,13].

Internationally, many countries and regions have already begun exploring and experimenting with evaluation standards for green restaurants [14]. However, these standards are often too generalized or only applicable to specific types of restaurants, failing to fully meet the diverse and unique needs of green restaurants. Currently, Taiwan’s evaluation indicators for green restaurants are incomplete, lacking systematic and objective assessment tools. This limits the recognition and competitiveness of green restaurants in the market. Therefore, it is necessary to conduct in-depth research to develop a set of scientifically grounded evaluation indicators suitable for green restaurants to promote their sustainable development and effectiveness and to support the growth and promotion of green restaurants.

The effects of green accounting on a restaurant’s environmental performance were examined by Halim et al. [15]. Green accounting in the restaurant industry can entail the use of renewable energy, environmentally friendly materials, or more effective waste management. Green restaurants are those that are constructed or operated in an environmentally friendly manner to lessen the environmental impact of their operations [16]. According to existing research, restaurant operations encompass a number of environmental issues linked to food, including cooking, serving, and food waste, as well as non-food issues, like energy and water waste [17].

Both industry and academia have paid close attention to the negative environmental effects of restaurants. The goal of Madanaguli et al. [18] was to locate, list, and compile the body of research on green concerns in the restaurant sector. Given the wide definition of “green,” we define “green” as any environmentally conscious practice implemented by a restaurant to reduce its environmental effect. These techniques could be directly related to the cuisine being served, or they could be related to the technology or atmosphere of the restaurant. However, restaurants have also been adopting green practices in recent years and have begun to enjoy a number of advantages, such as a greener reputation [19,20].

In summary, green restaurants have become one of the key topics of interest in the foodservice industry in recent years. They not only focus on the health and taste of food but also emphasize a responsible attitude toward the environment and society in their operations. Green restaurants typically aim to reduce their carbon footprint, conserve energy, minimize waste, and support local and sustainable agriculture to promote ecological balance and social well-being. The Green Restaurant Association [21] points out that green restaurants are increasingly gaining attention in contemporary society. These restaurants not only focus on the taste of food and the quality of service but also place significant emphasis on their impact on the environment and society.

2.2. The Evaluation Indicators

Evaluation indicators are an important tool for measuring the sustainable operation of green restaurants. These indicators cover various aspects, including environmental benefits, social responsibility, economic performance, and consumer preferences. The construction of these indicators needs to take into account the specific circumstances of different regions and types of restaurants to ensure the objectivity and effectiveness of the evaluation.

Scientific evaluation indicators can effectively improve the environmental performance of restaurants, thereby promoting the sustainable development of the entire industry. Establishing green restaurant evaluation indicators will help consumers more clearly identify and choose restaurants that align with their values and preferences, thereby driving the market toward more sustainable food choices. Based on the need to enhance restaurant competitiveness and market recognition, environmental friendliness and social responsibility, as important factors of consumer preference, can not only strengthen a restaurant’s brand image but also attract a broader customer base [22]. By establishing scientifically grounded and reasonable evaluation standards, green restaurants will be able to better assess and improve their sustainable development practices while gaining a competitive edge in the market.

This chapter provides a four-part summary of the internal logic of the evaluation indicator system from the perspectives of the system’s composition and structure, indicator calculation, and system calculation [23].

Several common green restaurant evaluation indicators and international certification organizations consider key factors to assess a restaurant’s environmental and sustainability performance. These include: (1) LEAF (Leadership in Energy and Environmental Design) Certification: Awarded by the Sustainable Restaurant Association in the UK, this certification evaluates a restaurant’s performance in environmental, social, and economic sustainability; (2) Green Restaurant Association (GRA): A U.S.-based non-profit organization that specializes in evaluating and certifying restaurants based on their green practices, including energy usage, waste management, sourcing of ingredients, and more; and (3) ISO 14001 Environmental Management System Certification: Although not specifically designed for restaurants, some restaurants choose to obtain ISO 14001 certification to demonstrate the effectiveness and sustainability of their environmental management systems.

These evaluation indicators and certification organizations not only help consumers to identify environmentally friendly restaurants but also encourage restaurant operators to improve and innovate in terms of environmental protection and sustainability.

2.3. Needs Assessment

Needs assessment is the process of understanding consumers’ needs and preferences regarding green restaurants. This includes consumers’ awareness of healthy eating and environmental dining concepts, their trust in environmental certifications and labels, and their willingness to pay a premium to support green restaurants. Consumers’ environmental awareness and concern for healthy eating are continuously increasing, which has led more and more restaurants to adopt green dining strategies to attract customers. It not only helps restaurants understand consumer needs but also guides them in developing new products and services that align with market needs.

According to Witkin and Altschuld [24] and Matt et al. [25], a needs assessment is “a systematic set of procedures undertaken for the purpose of setting priorities and making decisions about program or organizational improvement and allocation of resources.”

In Taiwan, the needs assessment for green restaurants primarily covers consumers’ preferences for environmentally friendly dining and market trends, as well as the challenges and opportunities restaurant operators face when implementing eco-friendly measures. Consumer preferences and market trends include six key points: (1) Environmental Awareness and Consumer Behavior: Taiwanese consumers’ emphasis on environmental protection and sustainable development is continuously increasing, with younger generations particularly inclined to choose products and services that support environmentally friendly practices. Wu et al. [26] showed that consumers are highly concerned about the sourcing of ingredients, eco-friendly packaging, and waste management in dining products and are willing to pay extra to support restaurants that engage in environmental practices. (2) Sustainability and Food Safety: Consumers have a strong preference for organic ingredients and food without additives, believing that such food is not only safe and healthy but also particularly important for being environmentally friendly. (3) Brand Recognition and Market Positioning: Environmental certifications and labels enhance a restaurant’s brand image and market competitiveness, attracting more environmentally conscious consumers. (4) Cost and Benefit Analysis: While adopting environmental practices may increase initial costs, long-term savings can be achieved through energy conservation, waste reduction, and efficiency improvements, ultimately increasing the brand’s value. (5) Regulatory and Certification Requirements: Restaurants need to comply with local and international environmental regulations and obtain relevant green restaurant certifications to increase consumer trust. (6) Supply Chain Management and Partnerships: Establishing partnerships with sustainable food suppliers and technology providers helps to ensure the traceability and environmental friendliness of ingredients, further supporting the restaurant’s eco-friendly practices.

In summary, the green restaurant market in Taiwan is facing favorable conditions, with rising consumer environmental awareness and increasing market needs. However, it also presents challenges for restaurant operators, including cost control, regulatory compliance, and supply chain management. Effective market analysis and strategic planning help restaurants to gain a competitive advantage and achieve sustainable development in this rapidly growing market.

3. Research Design and Implementation

To achieve this research goal, a mixed-methods approach combining both qualitative and quantitative research was employed. After a thorough review and analysis of the literature, qualitative research through Delphi expert interviews along with a combination of qualitative and quantitative survey research were used to confirm the appropriateness and consistency of the indicators. This approach helped in constructing the evaluation indicators for green restaurants in this study.

3.1. Research Framework

Based on the research motivation, objectives, literature review analysis, and conclusions from related studies, this research proposes a framework for evaluation indicators suitable for green restaurants. The framework includes the following steps: (1) First-level evaluation indicators (dimensions): These were constructed through the “literature analysis method” to form the overarching evaluation dimensions for green restaurants; (2) Second-level evaluation indicators (sub-dimensions): These were developed using the “expert interview method” to identify specific aspects within each dimension; and (3) Third-level evaluation indicators (detailed indicators): These were constructed to further refine the detailed criteria under each sub-dimension.

This multi-layered approach ensured a comprehensive and systematic development of evaluation indicators for green restaurant.

3.2. Participants

The participants in this study included experts and scholars from industry, government, and academia who are representative of the field and have a strong understanding of the research topic, as well as a genuine enthusiasm for participating. The selected subjects included senior chefs, restaurant managers, industry operators, scholars in related fields of culinary arts, and government officials involved in relevant departments.

3.2.1. Expert Interview Method Participants

The research subjects for this method included senior chefs, restaurant managers, operators, and culinary scholars. In-depth interviews were conducted, and opinions were gathered to establish the preliminary construction of the second-level evaluation indicators (sub-dimension indicators) and third-level evaluation indicators (detailed indicators).

3.2.2. Delphi Method Participants

For the Delphi method, it is ideal to select members from diverse backgrounds or positions to strengthen the process. When using a heterogeneous expert panel, the group size should typically range from 5 to 10 members. If the panel exceeds 10 members, the error in the group can be minimized, and the group’s reliability is maximized [27]. This study invited experts and scholars from industry, government, and academia, with a plan to invite 5 experts from the industry, including senior chefs and restaurant operators; 5 officials from the government, including personnel involved with the Green Restaurant program at the Agricultural Bureau; and 5 academic experts, including professors from culinary arts departments at major universities. In total, 15 experts and scholars were invited to participate.

3.3. Instrumentation

3.3.1. Professional Review

This study primarily focuses on the construction and validation of green restaurant evaluation indicators. In line with the research objectives and the issues to be addressed, the study provides relevant units with evaluation planning and serves as a reference for formulating teaching objectives. The draft of the evaluation indicators, which the researchers developed after theoretical and literature reviews, is presented in the form of a semi-structured questionnaire. This questionnaire was reviewed, interviewed, and modified by professionals.

3.3.2. Delphi Survey

The research tool gathered the data from the professional review and suggestions into the first round of the expert panel questionnaire. The content of the questionnaire at each level was designed based on the feedback from the expert panel, consisting of representatives from industry, government, and academia. In addition to incorporating the revision suggestions, a Likert five-point scale was used for responses. After collecting the responses, the expert panel’s feedback was summarized, and a structured questionnaire for the next round was developed. This process continued through successive rounds of responses from the expert panel until the feedback reached convergence and the statistical analysis results showed consistency.

The two-round Delphi technique questionnaire used in this study was distributed to members of the Delphi group on 15 October 2024 and 1 November 2024.

3.4. Research Design

The design process of this study was divided into five main steps: (1) Step 1—Literature Collection and Draft Construction: The first step involved the researcher gathering, compiling, and reviewing relevant literature to draft the evaluation indicators for green restaurants. (2) Step 2—Written Review and Discussion: In the second step, the draft content developed in Step 1 was subjected to written review. In addition to written feedback, individual telephone discussions were conducted to provide suggestions for revisions, which helped in the preliminary construction of the evaluation indicator content. (3) Step 3—Delphi Survey Method: The third step was to invite relevant experts and scholars to form an expert panel. The panel participated in semi-structured questionnaires (first round) and closed-ended questionnaires (second round onward) to gather consistent views from the experts, allowing the further development of detailed indicator content. (4) Step 4—Statistical Analysis and Verification: In the fourth step, statistical data were analyzed to verify the importance of the indicators and further validate the results based on expert feedback. (5) Step 5—Final Evaluation and Adjustment: Based on the statistical results and expert feedback, the evaluation indicators were finalized and adjusted to ensure consistency, effectiveness, and relevance for green restaurant evaluation.

3.5. Data Processing

The following is an explanation of how the research data were integrated and processed:

3.5.1. Expert Review Data Integration and Revision

The first step involved drafting the evaluation indicators for green restaurants through a literature review. This draft was then subjected to in-depth review by eight senior industry experts and chefs. The review process included one-on-one telephone discussions and interviews, where the experts’ professional opinions and practical experiences were gathered. The feedback from these interviews was carefully analyzed, and the collected insights from each professional were integrated to initially construct the various levels of dimensions for this study.

3.5.2. Data Integration and Consistency Confirmation

The research method was a mixed qualitative and quantitative research approach. Its main process involved multiple rounds of expert questionnaires and feedback to gain the most reliable consensus of a group of experts [28,29]. When the expert group consists of 6 to 10 or more individuals, the group’s error margin is minimized, and the credibility is higher.

In the qualitative part, expert group members could express their professional knowledge and practical experience without being influenced by external factors. Subsequently, the researcher conducted inductive analysis, integrated, and revised the data, using these insights to develop the next round of questionnaire items. After several rounds of revision, the final results were more scientific, objective, and impartial.

In the quantitative statistical analysis, the primary focus was the “green restaurant evaluation indicators questionnaire.” Expert group members rated the importance of each evaluation item using a Likert 5-point scale (“5” represents very important, “4” represents important, “3” represents neutral, “2” represents unimportant, and “1” represents very unimportant). In the first round, the questionnaire was semi-structured, and the expert group members also provided suggestions for additions, deletions, or revisions of each evaluation item.

Once the questionnaires were collected after each round, the data were encoded and organized. Statistical software was used for analysis, including the calculation of the mean and standard deviation of the variables. The following acceptance or deletion criteria were established for evaluating the consensus and appropriateness of the items based on statistical data:

(1)

Consistency test: The “standard deviation” of the responses from each round of expert group members was used to evaluate consistency. If the standard deviation of each evaluation item was ≤0.5, it was considered to have “high consistency”; if the standard deviation was ≤1.0, it was considered to have at least “moderate consistency.” The study considered that consensus among expert group members must be at least “moderately consistent” to be included as an evaluation indicator. If consensus was not reached, the item was deleted and not included in the next round.

(2)

Appropriateness test: The “mean score” of each round of expert group members’ responses was used to evaluate appropriateness. If the mean score of each evaluation item was ≥4.0, it was considered “highly appropriate”; if the mean score was ≥3.5, it was considered “moderately appropriate.” The study considered that the consensus among expert group members must be at least “moderately appropriate” for the item to be included as an evaluation indicator. If an item’s appropriateness was insufficient, it was deleted and not included in the next round.

To make the process more objective and rigorous, the consistency test of the expert group regarding the importance of the indicators used the non-parametric statistical method, the K–S (Kolmogorov–Smirnov) one-sample test. According to Tsai and Shyr [29], when the test reaches a significant level for a particular evaluation item (i.e., p < 0.05), it can be inferred that the group has reached consensus on that evaluation item.

4. Data Analysis and Discussions

The survey data collected in this study were organized and encoded, followed by statistical analysis, including the calculation of mean (M) and standard deviation (SD) for each option, as well as suitability and consistency analysis. The criterion for suitability selection was: mean ≥ 3.5; the criterion for consistency selection was: standard deviation ≤ 1. Additionally, to ensure that the results of this study were more rigorous, the Kolmogorov–Smirnov one-sample test was used to verify whether the survey results reached a consensus on the retained indicators (achieving statistical significance), thus confirming whether the expert survey results achieved consensus and consistency.

4.1. The Resource Management Dimension

The resource management dimension includes energy usage, water resource management, and waste management. According to the appropriateness statistical results, the average score for all the indicators is greater than 3.5. Additionally, in terms of consistency, the standard deviation for each sub-indicator is less than 1. As shown in

Table 1. Statistical analysis results of resource management dimension.

Indicator	M	SD	K–S Z-Test
1-1 Energy use
1-1-1 Proportion of energy-efficient appliances and equipment used	4.90	0.000	1.707 **
1-1-2 Power load management measures during peak electricity usage	4.32	0.712	1.807 **
1-1-3 Regular maintenance and inspections to improve equipment efficiency	4.01	0.590	1.420 *
1-1-4 Energy efficiency of indoor air conditioning and lighting systems	3.81	0.670	Consistency
1-1-5 Proportion of renewable energy used (e.g., solar power)	4.07	0.468	1.078 **
1-2 Water resource management
1-2-1 Use of water-saving equipment (e.g., low-flow faucets, sensor faucets)	5.00	0	Consistency
1-2-2 Water recycling and reuse measures for kitchen and restroom water	4.23	0.511	2.128 ***
1-2-3 Regular inspection and leak prevention measures	5.00	0	Consistency
1-2-4 Installation of rainwater collection systems for non-potable water use	4.87	0.425	2.377 ***
1-2-5 Employee education and awareness on water resource management	4.80	0.457	3.198 ***
1-3 Waste management
1-3-1 Completeness of waste classification and recycling system	4.77	0.452	3.357 ***
1-3-2 Waste treatment and reuse mechanism for restaurant food waste	4.73	0.488	2.840 ***
1-3-3 Reduction in the use of disposable tableware and packaging	4.60	0.532	2.582 ***
1-3-4 Implementation of sustainable procurement policies to reduce waste generation	3.32	0.686	1.807 **

* p < 0.05; ** p < 0.01; *** p < 0.001.

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4.2. The Ingredient and Product Selection Dimension

The ingredient and product selection dimension includes ingredient sustainability, sustainable product selection, and supply chain transparency. According to the appropriateness statistical results, the average score for all the indicators is greater than 3.5. Additionally, in terms of consistency, the standard deviation for each sub-indicator is less than 1. As shown in

Table 2. Statistical analysis results of ingredient and product selection dimension.

Indicator	M	SD	K–S Z-Test
2-1 Ingredient sustainability
2-1-1 Priority procurement of locally produced seasonal ingredients	4.27	0.704	1.649 *
2-1-2 Proportion of certified organic or non-toxic ingredients	4.53	0.516	2.236 ***
2-1-3 Reduction in the use of high environmental impact ingredients (e.g., rare or overfished seafood)	4.33	0.488	2.482 ***
2-1-4 Plant-based diets to reduce carbon footprint	4.78	0.421	3.198 ***
2-1-5 Promotion of ingredient packaging reduction	3.77	0.844	1.607 **
2-2 Sustainable product selection
2-2-1 Use of packaging materials from sustainable sources (e.g., recyclable packaging)	4.37	0.518	2.066 ***
2-2-2 Priority procurement of products with green eco-labels	4.70	0.438	2.840 ***
2-2-3 Reduction in the use of disposable products (e.g., plastic straws, plastic bags)	4.73	0.458	2.840 ***
2-2-4 Use of durable and reusable tableware and equipment	4.83	0.358	2.852 ***
2-2-5 Use of biodegradable and reusable packaging materials	4.10	0.511	1.678 **
2-3 Supply chain transparency
2-3-1 Does the restaurant provide information on the origin of ingredients (e.g., place of origin and producer details)?	4.73	0.258	3.513 ***
2-3-2 Does the restaurant choose to cooperate with suppliers who meet sustainability and ethical standards?	4.83	0.258	3.614 ***
2-3-3 Do suppliers meet environmental and social responsibility certifications (e.g., ISO)?	4.81	0.352	2.830 ***
2-3-4 Does the restaurant regularly review the environmental and social impact of its supply chain?	4.35	0.941	3.415 ***

* p < 0.05; ** p < 0.01; *** p < 0.001.

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4.3. The Environmental and Indoor Quality Dimension

The environmental and indoor quality dimension includes sound and noise management, indoor air quality, and indoor lighting and building materials. According to the appropriateness statistical results, the average score for all indicators is greater than 3.5. Additionally, in terms of consistency, the standard deviation for each sub-indicator is less than 1. As shown in

Table 3. Statistical results of environmental and indoor quality dimension.

Indicator	M	SD	K-S Z-Test
3-1 Sound and noise management
3-1-1 Use of soundproofing materials to reduce indoor echo and noise propagation	5.00	0	3.237 ***
3-1-2 Selection of low-noise kitchen and air conditioning equipment	4.93	0.358	3.410 ***
3-1-3 Regularly measure and control background noise levels within the restaurant	4.87	0.362	3.536 ***
3-1-4 Provide quiet areas to enhance customer dining comfort	4.73	0.458	2.940 ***
3-1-5 Encourage employees and customers to comply with the restaurant’s noise control policy	4.45	0.543	2.866 ***
3-2 Indoor air quality
3-2-1 Regularly change and maintain air conditioning and ventilation equipment filters	4.60	0.507	3.324 ***
3-2-2 Use air purification devices to reduce indoor pollutants (e.g., PM2.5, formaldehyde)	4.83	0.352	3.347 ***
3-2-3 Ban smoking inside the restaurant and provide a good external ventilation system	4.85	0.351	3.157 ***
3-2-4 Choose low-volatility organic compound (VOC) cleaning products and building materials	4.73	0.458	3.940 ***
3-2-5 Provide employees and customers with health information about indoor air quality	4.23	0.523	3.026 ***
3-3 Indoor lighting and building materials
3-3-1 Use high-efficiency energy-saving lighting to reduce energy consumption	4.80	0.410	3.568 ***
3-3-2 Optimize the use of natural light to reduce the need for artificial lighting	4.80	0.414	3.398 ***
3-3-3 Use environmentally certified building materials (e.g., FSC-certified wood)	4.73	0.458	2.840 ***
3-3-4 Install shading devices to improve indoor thermal comfort and light environment	4.50	0.500	3.789 ***

*** p < 0.001.

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4.4. The Green Certification and Management Dimension

The green certification and management dimension includes green certification, environmental management systems, and employee environmental education and participation. According to the appropriateness statistical results, the average score for all indicators is greater than 3.5. Additionally, in terms of consistency, the standard deviation for each sub-indicator is less than 1. As shown in

Table 4. Statistical analysis results of green certification and management dimension.

Indicator	M	SD	K–S Z-Test
4-1 Green certification
4-1-1 Obtain international or national environmental certifications (e.g., ISO 14001, LEED)	4.95	0	3.727 ***
4-1-2 Regularly audit and update certification standard compliance	4.93	0.358	3.815 ***
4-1-3 Does the restaurant disclose certification information to enhance consumer trust	4.87	0.362	3.765 ***
4-1-4 Promote certified green practices to influence the supply chain and community	4.15	0.543	2.923 ***
4-2 Environmental management system
4-2-1 Establish and implement environmental management goals (e.g., carbon reduction goals)	4.73	0.507	3.324 ***
4-2-2 Establish a monitoring and reporting system for restaurant environmental performance	4.73	0.352	3.347 ***
4-2-3 Develop energy, water, and waste management plans	4.75	0.361	3.940 ***
4-2-4 Collaborate with suppliers to implement environmental protection measures (e.g., carbon emission reduction)	4.33	0.554	3.026 ***
4-3 Employee environmental education and participation
4-3-1 Regularly organize environmental education and training activities for employees	4.78	0.456	3.568 ***
4-3-2 Encourage employees to propose environmental improvement suggestions and provide rewards	4.67	0.414	3.398 ***
4-3-3 Employees’ active participation in the restaurant’s green practices (e.g., resource sorting)	4.33	0.439	2.840 ***
4-3-4 Establish internal communication mechanisms to share environmental knowledge and success stories	4.33	0.458	3.727 ***
4-3-5 Regularly evaluate employees’ understanding and implementation of environmental measures	4.50	0.500	3.789 ***

*** p < 0.001.

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4.5. The Customer Awareness and Participation Dimension

The customer awareness and participation dimension includes customer awareness of green actions, customer willingness to participate in green actions, and customer satisfaction with green restaurant practices. According to the appropriateness statistical results, the average score for all indicators is greater than 3.5. Additionally, in terms of consistency, the standard deviation for each sub-indicator is less than 1. As shown in

Table 5. Statistical results of customer awareness and participation dimension.

Indicator	M	SD	K–S Z-Test
5-1 Customer awareness of green actions
5-1-1 Does the restaurant educate customers about environmental knowledge through signage, posters, or electronic messages?	4.00	0	3.123 ***
5-1-2 Do customers understand the restaurant’s green measures (e.g., ingredient sourcing, energy-saving facilities)?	4.93	0.358	3.785 ***
5-1-3 Does the restaurant design exclusive events to raise customers’ green awareness (e.g., environmental lectures)?	4.87	0.362	3.465 ***
5-1-4 Can customers identify the green action results marked in the restaurant (e.g., carbon reduction data)?	4.73	0.458	3.233 ***
5-1-5 Do customers understand the meaning of green certification labels or environmental standards?	4.44	0.543	3.132 ***
5-2 Customer willingness to participate in green actions
5-2-1 Are customers willing to bring their own utensils or purchase reusable items?	4.50	0.517	3.124 ***
5-2-2 Are customers willing to support the restaurant’s environmental measures (e.g., paying a green fee)?	4.63	0.392	3.407 ***
5-2-3 Does the restaurant provide mechanisms for customers to recycle waste (e.g., sorting trash bins)?	4.76	0.451	3.180 ***
5-2-4 Are customers willing to participate in the restaurant’s green initiatives (e.g., food-saving or bringing eco-friendly utensils)?	4.73	0.458	3.120 ***
5-2-5 Are customers willing to choose environmentally certified or low-carbon dishes as their preferred dining options?	4.81	0.512	3.323 ***
5-3 Customer satisfaction with green restaurant practices
5-3-1 Customer satisfaction with the restaurant’s environmental measures (e.g., plastic reduction, energy saving)	4.80	0.410	3.324 ***
5-3-2 Customer satisfaction with the quality of green dishes provided by the restaurant	4.60	0.414	3.347 ***
5-3-3 Do customers believe that the restaurant’s “green measures” enhance the dining experience?	4.13	0.458	3.157 ***
5-3-4 Customer satisfaction with the transparency of the green restaurant (e.g., public environmental performance data)	4.75	0.458	2.940 ***
5-3-5 Customer satisfaction with the green educational information provided by the restaurant, such as the clarity and practicality of green advocacy content	4.50	0.500	3.320 ***

*** p < 0.001.

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4.6. Discussions

Through a comprehensive literature review, this study identified five main dimensions, encompassing 15 sub-dimensions and 70 detailed indicators. The study proposed a preliminary list of indicators for green restaurants in Taiwan. The exploratory and preliminary nature of this study focused on identifying and prioritizing indicators through expert consensus (Delphi method) rather than presenting a statistically validated evaluation instrument. To accommodate ongoing advancements in sustainability practices, technologies, and policies, regular expert consultation meetings have been planned to periodically review and update these indicators.

The contributions and challenges faced by green restaurants today are multifaceted. The rise of green restaurants not only meets consumers’ growing needs for health and sustainability but also promotes a new business model and set of values within the foodservice industry. However, implementing the green restaurant concept comes with several challenges. In general, respondents indicated that all of the indicators were at least somewhat important. The results suggested that the large majority of identified indicators had an average score greater than 4.0. Only three of the indicators were less than 4.0. Respondents considered the three most important indicators (the average score equal to 5.0) to be: 1-2-1 Use of water-saving equipment, 1-2-3 Regular inspection and leak prevention measures, and 3-1-1 Use of soundproofing materials to reduce indoor echo and noise propagation, respectively.

Given that the concept of green restaurants remains underdeveloped and lacks consensus in Taiwan [29], this study primarily employed the Delphi technique to explore and construct green management standards for restaurants. This study referenced guidelines from organizations such as the Green Restaurant Association in the U.S. [21] and Green Table in Canada [30].

Maynard et al. [8] developed the first validated instrument for assessing and categorizing eateries based on sustainability indicators in Brazil. Their tool enables owners to classify restaurants according to high, medium, or low adherence to sustainable practices and assists customers in identifying these establishments. It is important to highlight that educating diners about sustainability through the thoughtful use of natural resources alongside raising awareness among food professionals and entrepreneurs are both effective strategies for achieving sustainability [31].

One potential limitation of the Delphi method lies in the considerable discretion involved in its application. Since the process depends heavily on the quality of expert feedback, careful analysis of responses is a significant responsibility of this study. Additionally, determining what constitutes sufficient consensus in the Delphi procedure remains challenging [32].

This study has several limitations: (1) Sample Size: The Delphi panel included 15 experts, primarily from industry, government, and academia, which limits the generalizability of the findings; (2) Methodological Scope: While the Delphi method ensures consensus, it does not allow for causal testing; and (3) Geographic Focus: The framework is specifically applied to Taiwan. Future research should consider expanding sample diversity (e.g., including customers and suppliers) and incorporating causal models to enhance the robustness and generalizability of the framework.

5. Conclusions and Suggestions

Based on the research objectives and questions to be answered in this study, the following conclusions are drawn. To achieve the research objectives, this study first used a “literature analysis” to collect, summarize, and organize the first-level evaluation dimension indicators. Then, “expert interviews” were conducted, and based on the experts’ opinions, the second-level dimension indicators were organized. Finally, the “Delphi method” was employed to integrate the ideas and opinions of experts and scholars, constructing the detailed evaluation indicators for green restaurants.

The content is described as follows: (1) Through literature review and analysis, it was confirmed that the first-level dimension indicators of this study include resource management, ingredient and product selection, environmental and indoor quality, green certification and management, and customer awareness and participation. (2) Experts were selected for interviews, and based on their opinions, a cross-comparison was conducted. The second-level sub-dimension indicators were confirmed, totaling 15 items. (3) A Delphi expert panel was selected to complete the questionnaire. After data processing, the statistical analysis of the mean (M) and standard deviation (SD) of each option were determined, including suitability and consistency analysis. To obtain more reliable results, the Kolmogorov–Smirnov one-sample test (K-S test) was used to check if the expert survey results agreed on the important indicators. Finally, the third-level detailed indicators of this study were confirmed, totaling 70 items.

The contributions and challenges faced by green restaurants today are multifaceted. The rise of green restaurants not only meets consumers’ growing needs for health and sustainability but also promotes a new business model and set of values within the foodservice industry. However, implementing the green restaurant concept comes with several challenges, such as the high cost of sourcing organic ingredients, improving energy efficiency, and deepening consumer education. A successful green restaurant needs to establish a reliable supply chain, develop a comprehensive environmental management plan, and closely collaborate with government agencies, non-governmental organizations, and community groups to jointly advance environmental and social responsibility practices.

The study does not involve a pilot application or case study in actual restaurant settings; instead, it concentrates on indicator development and validation by expert consensus. Field testing would offer useful information about the indicators’ future impact, difficulties, and usefulness. Furthermore, future follow-up studies could statistically validate these indicators through actual data collection and analysis (EFA/CFA, reliability testing).

Establish green restaurant evaluation standards to provide unified operational guidelines, supported by auditing and certification mechanisms. Provide policy subsidies and tax incentives for green restaurants to encourage the implementation of green measures. Promote the values and benefits of green restaurants, raising public awareness and support for environmentally friendly dining. Create official websites and platforms to publicly disclose green restaurant evaluation results, enhancing transparency and consumer confidence. Promote collaboration between restaurant operators and their supply chains to increase the use of environmentally-certified products. Support collaborative plans with educational institutions, such as practical training and joint research.

The research results can serve as a reference for course planning in related programs at universities and colleges, as well as for industry planning of green restaurants, and as a reference for the promotion of national sustainable environmental policies. Therefore, based on the results of this study, recommendations are provided for educational institutions related to green restaurants, official organizations related to green restaurants, the industry related to green restaurants, and future researchers. These are described as follows:

(1)

Course Design and Promotion: Incorporate green restaurant evaluation indicators into restaurant management professional courses, emphasizing practical applications of resource management, ingredient selection, environmental quality, and green certification. Promote interdisciplinary courses combining environmental science and restaurant management to enhance students’ sustainable development capabilities.

(2)

On-Campus Practice and Research Support: Simulate green restaurant operations on campus, allowing students to participate in practical operations and conduct benefit analysis. Encourage students to engage in green restaurant-related research and competitions, and provide research resources and guidance.

(3)

Public Education and Advocacy: Offer short-term training courses and workshops to promote the concepts and practices of green restaurants to the public. In line with government policies or societal needs, cultivate professionals equipped with green restaurant management skills.