How Warm Glow and Altruistic Values Drive Consumer Perceptions of Sustainable Meal-Kit Brands

Abstract

The contribution of meal kits to the waste problem has become a significant concern, leading consumers to demand sustainable practices from meal-kit companies. This study proposes a framework to understand customer behavior toward sustainable meal-kit brands that promote practices such as recycling and waste reduction. This study applies warm glow theory to investigate how pure and impure altruism affect consumers’ perceptions of a meal-kit brand’s sustainability, perceived price fairness, and continuance intention. The findings confirmed that meal-kit brands’ sustainable practices significantly enhanced consumers’ perceptions of brand sustainability, which in turn influenced their perceived price fairness and continuance intention. Furthermore, warm glow and altruistic values were found to significantly moderate the relationship between consumers’ perceptions of brand sustainability and their continuance intention. However, no significant moderating effects were observed between consumers’ perceptions of brand sustainability and perceived price fairness. This study contributes to a deeper understanding of the psychological mechanisms underlying consumer attitudes and behaviors toward meal-kit brands’ sustainability efforts.

1. Introduction

According to the Environmental Protection Agency, food packaging is a major source of plastic waste, with approximately 75.4% of all plastic entering landfills [1]. As meal kits continue to grow in popularity in the U.S. and around the world [2], their role in the waste problem is becoming a growing concern. Studies have shown that meal kits reduce greenhouse gas emissions by 33% compared to grocery store meals due to reduced food loss and waste from pre-portioned ingredients, lower transportation emissions during the final delivery stage, and reduced refrigeration-related emissions [3]. However, meal kits generate more packaging waste than grocery store meals, with a University of Texas at Austin study estimating an average of 3.7 pounds of additional packaging per meal [4]. Butler (2017) highlights that the ice packs used to preserve the freshness of Blue Apron meal kits weigh between 5 and 6 pounds (approximately 2.3 and 2.7 kg) per unit, resulting in approximately 192,000 tons of waste per year from that service alone [5]. In addition, some ice pack ingredients, such as sodium polyacrylate, are derived from fossil fuels and are not biodegradable [2].

To address these concerns, some meal kit brands have initiated sustainability practices. For example, Blue Apron have implemented a recycling program for its ice packs and freezer bags, though participation rates remain unclear [2]. However, Plated has not yet addressed environmental concerns, offering minimal guidance on recycling or disposal of ice packs. As consumer demand for sustainable practices grows [2], it is essential to understand whether and how meal-kit brands’ sustainability efforts influence consumer attitudes and behaviors.

Despite the increased interest in sustainability, there is limited research on whether a meal-kit brand’s sustainable practices influence consumers’ perceptions of brand sustainability and their subsequent behaviors. Moreover, the psychological mechanisms underlying these effects, particularly in terms of the role of warm glow and altruistic values, remain under-examined in the context of sustainable meal-kit consumption. To understand environmental behavior, altruistic values have been widely researched; however, the warm glow effect has attracted little attention in appreciating consumer attitudes to brand sustainability [6]. This research gap emphasizes the need for examining both variables together to better understand consumers’ decision-making process in relation to environmentally friendly meal-kit brands. Accordingly, this study assesses whether a meal-kit brand’s sustainability initiatives significantly shape environmentally conscious consumers’ perceptions and uncover the psychological drivers—warm glow and altruistic value—that influence their behavioral intentions.

Research suggests that altruistic values are crucial in shaping socially desirable and responsible behavior [7]. However, Andreoni (1990) argues that altruism alone does not fully explain prosocial behavior [8]. Instead, he proposes that individuals experience a “warm glow”—a sense of moral satisfaction—when contributing to environmental or social causes. Studies have demonstrated that some consumers purchase green products at a premium price not necessarily because they care about the environment but also because doing so makes them feel good about themselves [9,10]. According to Andreoni (1990), the desire for a warm glow is significant in prosocial behavior [8]. Warm glow is regarded as a form of ‘impure altruism,’ where individuals engage in pro-environmental behavior to derive psychological benefits or social recognition from their contributions after doing good [6,8,11].

This study investigates how warm glow motivations or pure altruistic values affect consumers’ responses to meal-kit brands’ sustainability initiatives. It therefore examines whether warm glow and altruistic values moderate the relationships between meal-kit sustainability practices, brand sustainability, consumers’ perceived price fairness, and continuance intention. It also explores the direct effect of meal-kit brands’ sustainable practices on consumers’ perceived brand sustainability and behavior toward meal-kit brands incorporating sustainability initiatives.

The significance of the study is in incorporating warm glow theory to explore the effects of pure and impure altruism on consumer perceptions and subsequent behaviors toward meal-kit brands’ sustainability efforts. This research contributes to knowledge on sustainability through emphasis on the role of customer psychology in predicting consumer behavioral responses to meal-kit brands’ sustainability initiatives. These insights could help meal-kit brands tailor their marketing strategies to strengthen relationships with their target audience.

2. Literature Review

2.1. Meal-Kit Brands’ Sustainable Practices and Perceived Brand Sustainability

Sustainability has become a major concern in consumers’ purchasing decisions. They expect brands to display a genuine commitment to environmental and social responsibility [12]. Empirical research demonstrated that a company’s sustainable practices, such as eco-friendly sourcing, waste reduction, and community involvement, improved consumers’ perceptions of a brand’s sustainability [13]. In the food service industry, this effect is more evident because tangible actions such as eco-friendly packaging serve as strong signals that reinforce perceptions of a brand’s sustainability [14]. In this study, a meal-kit company’s sustainable practices refer to brand’s implementation of tangible actions such as the recycling of shipping boxes and the use of eco-friendly packaging materials. It is therefore posited that sustainable practices by meal-kit brands will strengthen consumers’ perception of brand sustainability.

Perceptions of brand sustainability shaped by consumers is a determinant of their evaluation of the prices of products or services [15]. When consumers recognize that a brand holds a high level of environmental and social accountability, they tend to view premium pricing as fair or justified [15]. This perception of fairness arises from the understanding that sustainable practices often require extra costs and additional investments, which justifies higher pricing [16]. Previous research indicated that perceived value enhanced by sustainability cues reduces price sensitivity, especially for eco-friendly products [17]. For this reason, perceived brand sustainability is expected to have a positive influence on perceived price fairness for meal-kit brands.

Consumers’ perceptions of brand sustainability also strengthen their relationship with the brand through emotional connections. Consumers, who view a brand as socially and environmentally responsible, are more likely to perceive value congruence, which enhances loyalty and long-term commitment, eventually leading to continuous use of the brand [18,19]. Research in hospitality and food services has demonstrated that perceptions of sustainability are strong predictors of repeat purchase and revision intention [20]. Thus, it is posited that perceived brand sustainability influences consumers’ continuance intention toward meal-kit brands.

Therefore, the following hypotheses were formulated:

H1. 

Meal-kit brands’ sustainable practices will positively influence perceived brand sustainability.

H2. 

Perceived brand sustainability will positively influence perceived price fairness.

H3. 

Perceived brand sustainability will positively influence continuance intention.

2.2. Moderating Role of Warm Glow and Altruistic Value in the Relationship Between Sustainable Practices and Perceived Brand Sustainability

Psychological factors such as personal values are instrumental in shaping how consumers interpret and respond to a brand’s sustainability efforts [21]. Individuals with strong intrinsic motivation tend to trust and positively evaluate brands that reflect their values [22]. One mechanism that explains this tendency is the “warm glow effect,” which refers to the emotional rewards or satisfaction gained from engaging in socially and environmentally responsible behavior [8]. When consumers experience strong positive emotions, they tend to respond more positively to sustainability initiatives. This is because such behaviors satisfy their sense of self-confidence and moral satisfaction [23,24]. Existing research supports this view, showing that the benefits consumers receive from green products promote pro-environmental behavior [25] and that positive benefits associated with brands contribute to consumers’ positive responses [26]. Therefore, we expect the warm feeling effect to amplify the impact of sustainability practices on consumers’ perceptions of a brand’s sustainability by reinforcing consumers’ positive perceptions (H4a).

Another important moderating factor is altruistic values. Altruistic values refer to a mindset in which individuals prioritize the well-being of others and the well-being of the environment over their own interests [21]. Individuals with high altruistic values are more sensitive to ethical and environmental issues than those without, and therefore tend to perceive brands with sustainable practices as truly sustainable [27]. These consumers place greater trust in brands that demonstrate social responsibility, which reinforces their perception of the brand’s sustainability [28]. Warm glow and altruistic values together contribute to explaining the variability in consumers’ responses to brand sustainability efforts, suggesting that the effectiveness of such initiatives may depend on individual consumer differences rather than simply on the actions themselves [29]. Specifically, warm-glow altruism enhances the moral satisfaction derived from a brand’s sustainability initiatives, amplifying positive evaluations, while pure altruism strengthens evaluations when initiatives have tangible environmental or social impact. Experimental studies have shown that groups with strong warm glow effect tendencies maintain strong willingness to pay regardless of the size of the influence, while groups with stronger pure altruism tendencies show an increase in willingness to pay as the influence increases [30]. Therefore, we expect the altruistic values to strengthen the influence of sustainability practices on consumers’ perceptions of a brand’s sustainability by reinforcing their altruistic motivations (H4b).

H4. 

Warm glow and altruistic values will moderate the relationship between meal-kit sustainable practices and perceived brand sustainability.

H4a. 

The warm glow will moderate the relationship between meal-kits’ sustainable practices and perceived brand sustainability.

H4b. 

Altruistic value will moderate the relationship between meal-kits’ sustainable practices and perceived brand sustainability.

2.3. Moderating Role of Warm Glow and Altruistic Value in the Relationship Between Perceived Brand Sustainability and Perceive Price Fairness

When individuals have a strong ethical or emotional bond with a brand, they tend to perceive premium pricing as justified [31]. Individual psychological characteristics, particularly ethical and personal values, are crucial in translating perceptions of brand sustainability into evaluations of price fairness [32]. The ‘warm-glow effect’—an emotional reward gained from participating in sustainable consumption—has been shown to increase consumers’ willingness to accept premium prices when they perceive a brand as sustainable [33]. When customers experience positive emotions from using the brand, their perceived value enhances favorably, reducing resistance to high-priced products and services, and positively influencing perceptions of price fairness [34].

Furthermore, consumers with strong altruistic values are more likely to perceive that paying higher prices for products/services from ethical or eco-friendly companies contributes to social and environmental welfare. This value strengthens the moral justification for paying higher prices for sustainable products and services [35]. Previous studies emphasize that consumers with altruistic values are more likely to accept higher prices associated with ethical and socially responsible brands, highlighting the need for research on the moderating role of altruistic values in perceptions of price fairness [36].

Based on the above, we propose that consumer psychological factors moderate the relationship between perceived brand sustainability and perceived price fairness. Specifically, warm feelings are expected to amplify the positive effect of perceived brand sustainability on perceived price fairness (H5a). Altruistic values are also hypothesized to moderate this relationship, strengthening consumers’ acceptance of premium prices for sustainability brands (H5b). These psychological factors may explain individual differences in how sustainability perceptions influence judgments of price fairness.

H5. 

Warm glow and altruistic values will moderate the relationship between perceived brand sustainability and perceived price fairness.

H5a. 

The warm glow will moderate the relationship between perceived brand sustainability and perceived price fairness.

H5b. 

Altruistic value will moderate the relationship between perceived brand sustainability and perceived price fairness.

2.4. Moderating Role of Warm Glow and Altruistic Value in the Relationship Between Perceived Brand Sustainability and Continuance Intention

Psychological factors play an important role in shaping consumers’ long-term loyalty to sustainable brands [37]. When consumers empathize with a brand’s ethical and sustainability policies, they are more likely to maintain their purchasing behavior over time, which strengthens their loyalty [38]. The positive emotional reward of “feeling good” gained from participating in sustainable consumption has been shown to strengthen consumers’ emotional attachment to sustainable brands by reinforcing their intention to continue [22]. This emotional reinforcement deepens consumer loyalty and reduces the likelihood of switching to competing brands [39].

Additionally, altruistic values enhance brand loyalty by strengthening moral and emotional connections with brands that embody social responsibility and sustainability [40]. Consumers with strong prosocial values exhibit stronger intentions to continue with brands that align with their ethical beliefs and contribute to social good [41,42]. However, it is unclear whether the combined effect of the warm glow effect and altruistic values explains consumer behavioral variability and strengthens the influence on future intentions toward brand sustainability [43]. Therefore, the warm glow effect and altruistic values, as consumer psychological factors, are proposed as moderating variables in the relationship between perceived brand sustainability and continued usage intentions.

H6. 

Warm glow and altruistic values will moderate the relationship between perceived brand sustainability and continuance intention.

H6a. 

The warm glow will moderate the relationship between perceived brand sustainability and continuance intention.

H6b. 

Altruistic value will moderate the relationship between perceived brand sustainability and continuance intention.

A conceptual model is presented in Figure 1.

3. Method

3.1. Data Collection, Measurement and Analysis

An online survey was conducted using Amazon Mechanical Turk (MTurk), a well-known online survey platform. Screening criteria were applied to select participants who reside in the U.S. and had used a meal-kit brand that promoted or supported environmental protection activities within the three months prior to participating in the survey.

A pilot survey was conducted with 50 participants to validate the questionnaire prior to the main survey. Out of the 350 responses collected, 317 were retained after excluding incomplete or unreliable data, and this data was used for further analysis.

The survey consisted of two main sections. The first section measured four key elements: meal-kit brand sustainable practices, perceived brand sustainability, perceived price fairness, and continuance intention. The sustainable practices item reflects the extent to which the brand implements sustainable measures such as the use of recyclable shipping boxes, use of eco-friendly packaging materials, and promotion of green behaviors through rewards programs. The sustainable practices items were adapted and modified from Khan and Sowards (2018) [2]. The perceived brand sustainability category was borrowed from Huang and Guo (2021) [44] and modified to suit the research objectives. The perceived price fairness items were based on Hwang et al. (2019) [45], and continuance intention items were borrowed from the established consumer behavior scales by Jang et al. (2015) [40]. The second section included items measuring moderating variables—warm glow and altruistic values—borrowed and modified from Hartmann et al. (2012) [34]. All items were measured on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). The last part of the questionnaire collected demographic information, including gender, age, ethnicity, marital status, and other relevant characteristics.

Data analysis was performed using IBM SPSS Statistics 26.0. Multiple regression analyses were used to verify the main effects of the constructs. Additionally, hierarchical regression analyses were conducted to investigate the moderating effects of warm glow and altruistic values on the relationships between sustainable practices, brand sustainability, perceived price fairness, and continuance intention. The study was approved by the Institutional Review Board of the research university.

3.2. Sample Profile

Table 1. Demographic Information of Respondents.

	Variables	Frequency	%
Gender	Male	207	65.3
	Female	110	34.7
Age	20–24	52	16.4
	25–34	166	52.4
	35–44	63	19.9
	45–54	32	10.1
	55–64	3	0.9
	65 and above	1	0.3
Ethnicity	Caucasian, non-Hispanic	276	87.1
	Hispanic or Latino	25	7.9
	African American	5	1.6
	Asian	7	2.2
	Other (specify below)	4	1.3
Marital status	Married	282	89.0
	Never Married	33	10.4
	Widowed	2	0.6
Education	High school diploma or below	44	13.9
	Some college	5	1.6
	2-year college	14	4.4
	4-year college	176	55.5
	Post graduate	16	5.0
	Professional degree	61	19.2
	Others (specify)	1	0.3
Occupation	Technical/Administrator	58	34.7
	Sales/Service	68	25.7
	Professional	77	24.3
	Managerial	95	12.4
	Operator/Fabricator/Laborer	7	2.0
	Homemaker	2	1.0
	Student	7	2.2
	Other	3	0.9
Annual household income	Less than $50,000	24	7.6
	$50,000~$74,999	108	34.1
	$75,000~$99,999	151	47.6
	$100,000~$149,999	25	7.9
	Over $150,000	9	2.8
Total		317	100

shows the demographic characteristics of the survey respondents. Among all respondents, 65.3% were male and 34.7% were female. By age group, over half (52.4%) were aged 25–34, followed by 35–44 (19.9%), 20–24 (16.4%), and 45–54 (10.1%). By race, White Americans constituted the overwhelming majority (87.1%), followed by Hispanic or Latino respondents at 7.9%, Asian respondents at 2.2%, and African American respondents at 1.6%. A significant proportion of respondents (89.0%) reported being married.

Regarding educational background, 55.5% held a bachelor’s degree. This was followed by professional degrees (19.2%), high school graduates or below (13.9%), some college or an associate’s degree (6.0%), and graduate degrees (5.0%). By occupation, 34.7% worked in technical or administrative roles. Other major occupations included sales or service occupations (25.7%), professional occupations (24.3%), and managerial occupations (12.4%). By annual household income, 47.6% reported incomes between $75,000 and $99,999, while 34.1% reported incomes between $50,000 and $74,999. Approximately 10.7% recorded incomes exceeding $100,000, while 7.6% reported incomes below $50,000.

In terms of the representativeness of the sample used in the study, several differences emerge when compared to the U.S. demographics. The sample is more male at 65.3%, compared to 49.5% in the U.S. general population; the sample is also more likely to be in the 25–34 age group at 52.4%. By race, Caucasian respondents made up 87.1% of the sample, significantly higher than the 61.5% in the U.S. population, with relatively few Hispanic/Latino, African American, and Asian respondents. These differences should be considered as limitations when generalizing the findings to the U.S. population as a whole.

4. Results

4.1. Reliability and Validity Assessments

Exploratory factor analysis was performed using principal component analysis with Varimax rotation. The results are detailed in

Table 2. Exploratory Factor Analysis and Reliability Analysis.

		Factor Loading	Eigen Value	Variance (%)	Cronbach’α
Sustainable Practices	The shipping box is readily recyclable.	0.787	2.661	29.567	0.826
	The meal-kit brand uses packaging and containers made from recyclable materials.	0.828
	The meal-kit brand implements a rewards program to promote green behavior, such as discounts for using reusable bags.	0.764
Brand Sustainability	The meal-kit brand takes an interest in and pays attention to matters that affect the general public, such as social or environmental issues.	0.821	1.540	17.109	0.795
	Meal-kit brand assumes social responsibility.	0.708
Price Fairness	The meal-kit brand justifies higher prices.	0.738	1.496	16.627	0.715
	A higher price for the meal-kit brand is fair.	0.849
Continuance Intent	In the future, I would continue to use the meal-kit brand.	0.786	1.394	15.491	0.728
	I will use the meal-kit brand next time with pleasure.	0.844
	Total variance(%)			78.794
	KMO			0.914
	Bartlett test			1410.026 (36) sig 0.000 (<0.001)

. Four distinct factors were derived—sustainable practices, brand sustainability, price fairness, and continuance intention—which explain 78.8% of the total variance. The factor loadings of the identified components ranged from 0.708 to 0.828, all of which were statistically significant and consistent with the recommended threshold [46]. The Kaiser–Meyer–Olkin statistic was 0.914, exceeding the minimum adequacy threshold of 0.6. Additionally, Bartlett’s sphericity test showed statistically significant results (p < 0.001). Internal consistency was assessed using Cronbach’s alpha, with values ranging from 0.715 to 0.826, indicating an acceptable level of reliability (α ≥ 0.70) [47].

4.2. Analysis of Main Effects

Table 3. Regression analysis of Hypotheses 1,2 and 3.

	Dependent Variable	Independent Variable	Unstandardized Coefficients		Standardized Coefficients	t-Value	Sig
			B	Std. Error	Beta
H1	Brand Sustainability	Sustainable Practices	0.688	0.049	0.622	14.092	<0.001
	R = 0.622, R2 = 0.387, Adjusted R2 = 0.385 F = 198.595 p < 0.001
H2	Price Fairness	Brand Sustainability	0.588	0.044	0.598	13.243	<0.001
	R = 0.598, R2 = 0.358, Adjusted R2 = 0.356 F = 175.385 p < 0.001
H3	Continuance Intention	Brand Sustainability	0.588	0.043	0.610	13.671	<0.001
	R = 0.610, R2 = 0.372, Adjusted R2 = 0.370 F = 186.890 p < 0.001

shows the results of the regression analyses. The findings confirmed significant relationships while supporting the proposed hypotheses. First, sustainable practices were found to exert a strong positive influence on brand sustainability (β = 0.622, p < 0.001), explaining 38.5% of the variance, thereby supporting Hypothesis 1. The indicates that consumers perceive a brand as more sustainable when it exerts higher levels of sustainable practices.

Second, brand sustainability positively influenced perceived price fairness (β = 0.598, p < 0.001), explaining 35.6% of the variance; hence, Hypothesis 2 was supported. This indicates that consumers with stronger perceptions of brand sustainability tend to perceive its price premium as acceptable.

Third, brand sustainability significantly positively influenced consumers’ intention to continue purchasing (β = 0.610, p < 0.001), explaining 37.0% of the variance; hence, Hypothesis 3 was supported. The finding indicates that consumers are more likely to have continuance intention to use the brands they perceive as sustainable.

Collectively, these results emphasize that the sustainability practices adopted by meal-kit brands significantly shape consumers’ perceptions of brand sustainability. Furthermore, this perception is a crucial factor in both consumers’ willingness to accept premium prices and their future repurchase intentions. This supports the notion that specific, visible efforts by meal-kit companies, such as using recyclable shipping boxes and packaging, and offering discounts for using reusable bags, positively influence consumers’ perceptions of the brand and, consequently, their behavioral intentions.

4.3. Assessment of Moderation Hypotheses

Table 4. Hierarchical Regression Analysis for Hypotheses 4.

Dependent Variable		Brand Sustainability
Independent Variable	Step 1	Step 2	Step 3
Sustainable Practices	0.622 ***	0.019	0.020 ***
Warm Glow		0.483 ***	0.532 ***
Altruistic value		0.359 ***	0.328 ***
Sustainable Practice × Warm Glow			0.134 *
Sustainable Practice × Altruistic Value			0.095 *
R2	0.387	0.622	0.629
ΔR2		0.235 ***	0.007 *
F	198.595 ***	171.752 ***	105.656 ***

* p < 0.05, *** p < 0.001.

presents the hierarchical regression analysis results which examine the moderating effects of warm glow and altruistic value on the relationship between sustainable practices and brand sustainability (Hypothesis 4). All predictor variables were standardized to minimize multicollinearity prior to creating interaction terms.

In Step 1, sustainable practices alone significantly predicted brand sustainability (β = 0.622, p < 0.001), explaining 38.7% of the variance (R² = 0.387, F = 198.595, p < 0.001).

In Step 2, warm glow (β = 0.483, p <0.001) and altruistic value (β = 0.359, p < 0.001) were added, significantly improving the model (ΔR² = 0.235, p < 0.001). Together, these three predictors explained 62.2% of the variance in brand sustainability (R² = 0.622, F = 171.752, p < 0.001). This demonstrates that consumers’ feelings of warm glow and altruistic values both have strong direct effects on their perceptions of brand sustainability, beyond the influence of sustainable practices alone.

In Step 3, interaction terms of both sustainable practices with warm glow (β = 0.134, p < 0.05) and sustainable practices with altruistic value (β = 0.095, p < 0.05) were entered to test the moderating effects. The addition of these interaction terms resulted in a small but significant increase in variance explained (ΔR² = 0.007, p < 0.05), with the full model explaining 62.9% of variance (R² = 0.629, F = 105.656, p < 0.001).

The positive and significant coefficients for both interaction terms indicate that the relationship between sustainable practices and brand sustainability is strengthened when consumers experience higher levels of warm glow or altruistic values. That is, in consumers who feel emotionally rewarded by sustainable consumption (warm glow) or who possess strong altruistic values, the influence of a brand’s sustainable practices on brand sustainability is more influential. These findings suggest that the values consumers uphold, particularly regarding sustainability, play a significant role in the psychological mechanisms underlying meal-kit consumers’ sustainable consumption behavior.

Taken together, these findings provide empirical support for Hypothesis 4, demonstrating that warm glow and altruistic value moderate the impact of sustainable practices on perceptions of brand sustainability.

Table 5. Hierarchical Regression Analysis for Hypotheses 5.

Dependent Variable		Perceived Price Fairness
Independent Variable	Step 1	Step 2	Step 3
Brand Sustainability	0.598 ***	0.099	0.052
Warm Glow		0.296 ***	0.271 ***
Altruism		0.369 ***	0.367 ***
Brand Sustainability × Warm Glow			0.071
Brand Sustainability × Altruistic Value			0.053
R2	0.358	0.512	0.521
ΔR2		0.154 ***	0.010 *
F	175.385 ***	109.246 ***	67.701 ***

* p < 0.05, *** p < 0.001.

presents the results of hierarchical regression which investigates the moderating effects of warm glow and altruistic value on the relationship between brand sustainability and price fairness.

In Step 1, brand sustainability significantly predicted price fairness (β = 0.598, p < 0.001), explaining 35.8% of the variance (R² = 0.358, F = 175.385, p < 0.001).

In Step 2, warm glow (β = 0.296, p < 0.001) and altruistic value (β = 0.369, p < 0.001) were added as additional predictors, significantly improving the model fit (ΔR² = 0.154, p < 0.001). Together, these variables explained 51.2% of the variance in price premium (R² = 0.512, F = 109.246, p < 0.001). This suggests that consumers’ emotional rewards from sustainable consumption (warm glow) and altruistic values independently contribute to perceived price fairness in addition to perceptions of brand sustainability.

In Step 3, an interaction term between brand sustainability and warm glow (β = 0.071, p > 0.05) and an interaction term between brand sustainability and altruistic value (β = 0.053, p > 0.05) were added to assess moderation effects. The explanatory power of the overall model increased slightly (R² = 0.521), with the increase being small but statistically significant (ΔR² = 0.010, p < 0.05). However, neither interaction term achieved statistical significance individually, suggesting that warm feelings and altruistic value did not significantly moderate the effect of brand sustainability on price fairness.

Overall, brand sustainability, warm glow, and altruistic value each exert a significant direct influence on consumers’ acceptance of price premiums. However, the hypotheses regarding the moderating effects of warm glow and altruistic value on the relationship between brand sustainability and price fairness were not supported; hence, Hypothesis 5 was not supported.

Table 6. Result of Hierarchical Regression Analysis for Hypothesis 6.

Dependent Variable		Continuance Intent
Independent Variable	Step 1	Step 2	Step 3
Brand Sustainability	0.610 ***	0.009	0.003
Warm Glow		0.339 ***	0.385 ***
Altruism		0.462 ***	0.406 ***
Brand Sustainability × Warm Glow			0.151 *
Brand Sustainability × Altruistic Value			0.192 *
R2	0.372	0.597	0.604
ΔR2		0.225 ***	0.007 *
F	186.890 ***	154.575 ***	94.901 ***

* p < 0.05, *** p < 0.001.

presents the hierarchical regression analysis results, which examines the moderating effects of warm glow and altruistic value on the relationship between brand sustainability and continuance intention.

In Step 1, brand sustainability had a significant influence on continuance intent (β = 0.610, p < 0.001), explaining 37.2% of the variance (R² = 0.372, F = 186.890, p < 0.001).

In Step 2, warm glow (β = 0.339, p < 0.001) and altruistic value (β = 0.462, p < 0.001) were added to the model, significantly improving the explained variance (ΔR² = 0.225, p < 0.001). The three predictors together accounted for 59.7% of the variance in continuance intent (R² = 0.597, F = 154.575, p < 0.001). This indicates that consumers’ emotional satisfaction (warm glow) and altruistic values have strong direct effects on their intention to continue supporting the brand, beyond the influence of brand sustainability construct alone.

In Step 3, the interaction terms of brand sustainability with warm glow (β = 0.151, p < 0.05) and with altruism (β = 0.192, p < 0.05) were inserted into the model to test the moderating effects. The inclusion of these terms resulted in a small but significant increase in explained variance (ΔR² = 0.007, p < 0.05), with the full model explaining 60.4% of the variance (R² = 0.604, F = 94.901, p < 0.001).

The positive and significant interaction coefficients indicated that warm glow and altruistic value moderated the relationship between brand sustainability and continuance intention. Specifically, the impact of brand sustainability on consumers’ continuance intent was stronger among consumers with higher levels of warm glow or altruistic values. This suggests that consumers’ levels of warm glow and altruistic values serve as indicators of the likelihood of maintaining a long-term relationship with the brand. Individuals with higher levels of these values are more likely to continue engaging with the brand, thereby supporting sustained brand profitability.

Overall, these findings provide support for the moderating roles of warm glow and altruistic value in amplifying the effect of brand sustainability on consumers’ continuance intention, thereby confirming Hypothesis 6.

5. Discussions and Conclusions

This study investigated the relationships among sustainable practices, brand sustainability, warm glow, altruistic value, price fairness, and continuance intention. The findings align with those of previous studies, but offer meaningful insights into the roles of emotional and ethical consumer characteristics.

Consistent with previous studies [32,48], this study confirmed that sustainable practices significantly enhanced perceptions of brand sustainability. This supports the notion that consumers reward brands that actively engage in sustainability efforts with greater trust and higher perceived value. Furthermore, the positive effects of brand sustainability on perceived price fairness and continuance intention validated findings by Hwang and Lacy (2019) [48], who reported that perceptions of sustainability drive consumers’ willingness to pay more and remain loyal.

The moderating roles of warm glow and altruistic value also align with existing literature emphasizing psychological drivers behind sustainable consumption. The significant moderating effect observed in the path from sustainable practices → brand sustainability → continuance intention reflects the emotional reward mechanism identified by Hartmann et al. (2017) [43] and Hwang and Lacy (2019) [48], where consumers’ intrinsic moral satisfaction amplifies the influence of sustainability on brand attitudes and behaviors. Similarly, altruism’s moderating effect reflects the importance of ethical awareness emphasized by Luchs et al. (2010) [32]. However, in contrast to Hartmann et al. (2017) [43] suggesting that the warm glow effect exerted a stronger influence on individuals’ pro-environmental behavior than altruism, this study showed the opposite result: altruistic values exerted a slightly greater impact on subsequent behaviors, such as the intention to continue using a more sustainable meal-kit brand [34].

However, the weak and insignificant moderating effects on the brand sustainability → price fairness relationship differ somewhat from existing research. While some studies (e.g., [48]) reported stronger moderation effects on price-related outcomes, our findings suggest that price premium decisions may be influenced by additional factors beyond emotional and altruistic characteristics, such as economic considerations or perceived value for money [49]. This contributes to the ongoing debate about the limits of psychological influences on consumer price acceptance.

Overall, this study extends the literature by simultaneously testing both direct and moderating effects of warm glow and altruistic value within a comprehensive model linking sustainable practices to key consumer outcomes. The findings suggest that marketing strategies should emphasize not only sustainable actions but also engage consumers emotionally and ethically to maximize brand sustainability and long-term loyalty.

5.1. Theoretical and Practical Implications

This study contributes to sustainability-related literature by introducing emotional and ethical psychological concepts such as warm glow and altruistic values as moderating variables in the relationship between sustainable practices of meal-kit companies, perceptions of brand sustainability, and consumer attitudes and behaviors. While previous studies (e.g., [32,48]) examined these concepts individually within their proposed models, this study simultaneously analyzes their moderating effects within a comprehensive model.

The significant moderating role of warm emotions and altruistic value highlights the importance of intrinsic psychological rewards and ethical values in the mechanism through which consumers perceive sustainability initiatives and translate them into action. This demonstrates that the influence of corporate sustainable practices on enhancing consumers’ perceptions of brand sustainability and strengthening their intention to maintain relationships with the brand depends on consumers’ emotional rewards and moral motivations, thereby expanding existing frameworks related to decision-making processes concerning sustainable consumption.

Contrary to our hypothesis, the analysis did not confirm a moderating effect of psychological variables on consumers’ perceptions of price fairness. This suggests that the relationship between psychological characteristics and price fairness judgments in sustainability contexts may be more dependent on various situational variables. It implies the need for further theoretical refinement on how diverse situational variables and contexts influencing consumer decision-making affect sustainability-related emotions [9].

For practitioners, these findings imply that sustainability practices are crucial for building positive consumer perceptions and fostering lasting relationships, necessitating continuous efforts toward sustainability. They also underscore the importance of strategically communicating such sustainability efforts to appeal to consumers’ personal values and characteristics, specifically, to engage them on emotional and ethical levels. Marketing practitioners can enhance brand sustainability awareness and increase customer loyalty by developing marketing campaigns that emphasize the personal satisfaction and social benefits gained from choosing sustainable brands, thereby evoking a warm glow effect [49]. A marketing strategy that emphasizes meal-kit sustainability efforts and aligns with consumers who have high levels of environmental consciousness can strengthen brand image and enhance competitiveness in the meal-kit market [50]. Iweala et al. (2019) noted that emphasizing the effect of warm glow in social marketing strategies increases consumer purchases of products promoting ethical or environmentally friendly claims [51].

When hedonic rewards are clearly communicated, environmentally and ethically conscious consumers become more inclined to reciprocate by engaging in prosocial and eco-friendly consumption. To maximize this effect, brands should design messaging and experiences that reinforce consumers’ internal rewards for supporting sustainability [9]. Storytelling, social cause marketing, or participation in community sustainability initiatives can deepen consumers’ emotional connection and moral identification with the brand [32,42].

However, contrary to our predictions, the moderating effects of warm glow and altruistic values on perceived price fairness were not observed, offering significant implications for meal-kit managers or marketers. Specifically, marketers must recognize that consumers may experience a decision-making process involving more complex variables that can influence their willingness to pay for ethical and socially conscious brands. For example, they must recognize that perceived economic value and competitive pricing can influence consumers’ price fairness perceptions. Therefore, to develop effective pricing strategies, it is recognized that balancing ethical appeals with persuasive value propositions is necessary to gain consumer support.

5.2. Limitations and Future Research

Because environmental awareness levels may vary across cultures, the results of this study may not be generalizable to all consumer groups. Additionally, this study used a survey, which could introduce social desirability bias and lead respondents to exaggerate their attitudes toward sustainability. Social identity theory and self-determination theory could also enhance our understanding of consumer behavior in the context of sustainability. The complexity of the proposed model may limit the clarity of causality, suggesting that future research may benefit from validating simplified or alternative models. Finally, while the demographic distribution of the sample used in this study’s analysis provides useful insights, it may not be fully representative of the entire population of meal kit users. Future studies could employ stratified sampling to increase demographic balance and improve generalizability. Addressing these limitations in future research could provide a more comprehensive understanding of consumer behavior in the context of sustainability.