Introduction

Reducing food waste offers numerous advantages for both individuals and the environment, including enhanced food security, reduced costs, and alleviation of pressures on water, land, biodiversity, and waste management systems1. However, this remains an unresolved challenge, underscored by global attention sparked in 2011 following a report by the Food and Agriculture Organization of the United Nations (FAO), which revealed that approximately one-third of the world’s food production is lost or wasted annually, amounting to 1.3 billion tonnes1. Notably, 931 million tonnes of this waste occur across three sectors, with households accounting for 61%, food service for 26%, and retail for 13%1. The food service sector presents a unique challenge due to its diverse subsectors; assessing food waste is particularly complex1. One notable subsector is the healthcare industry, where hospitals stand out as energy-intensive establishments operating continuously, 365 days a year2. For instance, hospitals allocate substantial funds toward food procurement to cater to the needs of patients, visitors, and staff, serving thousands of meals daily3.

Moreover, hospitals are significant contributors to food waste due to wastage occurring at various stages of the food service process, including ingredient preparation, cooking, serving, and storage. Indeed, waste generated from meal preparation, tray assembly (prepared food not served), and plate leftovers (food served but unconsumed) can comprise up to 50% of the total waste generated in a hospital ward3. Compared to other food service sectors like restaurants, schools, cafes, and workplace canteens, plate waste in hospitals is estimated to be two to three times higher4. Additionally, nearly 30% of hospitalized patients are vulnerable to malnutrition, attributed to factors such as eating difficulties leading to unpredictable changes in appetite and necessitating varied food items and services5. Given the nutritional, financial, and environmental implications, reducing plate waste in hospitals has become a key priority for food service management5. Achieving these goals requires meticulous meal preparation, delivery, and patient compliance. Research by Hong and Kirk6 underscores the importance of patients’ meal consumption in evaluating their dietary status and satisfaction with food service. Furthermore, the quality of food service significantly influences patients’ overall satisfaction during their hospitalization7.

In response to the increasingly competitive healthcare landscape and the rising expectations of patients, healthcare providers are adopting a customer-centric approach7. This shift has prompted dietitians to enhance the quality of food services despite resource limitations. Parasuraman et al. highlighted the multifaceted nature of quality, with the American Society for Quality defining it as meeting expressed or implied needs while being devoid of flaws7. In service marketing, quality is interpreted as meeting customer expectations. Given these definitions and the objectives of hospital food service departments, quality in hospital food service can be construed as delivering meals that fulfill the nutritional requirements of in-patients7. Despite having a clear concept, elevating the quality of food services in hospital environments remains complex.

Food service encompasses tangible and intangible aspects enhancing quality, so attention must be paid to various factors, including menu variety, portion control, presentation, cleanliness, and customer service. When evaluating food service quality, patients consider taste, nutritional value, cleanliness, temperature, portion sizes, meal timing, and staff attitude7. Notably, areas that often receive negative feedback include food temperature, service efficiency, meal timing, taste, portion sizes, menu diversity, availability of nutritional information, responsiveness to concerns, and hygiene practices7.

To our knowledge, no prior studies conducted in Lebanon have quantified plate waste or evaluated its determinants within hospital settings. Existing research on this topic in Lebanon has primarily focused on household and restaurant levels8,9,10,11,12. Therefore, addressing this issue within hospital settings is imperative to understand better the food waste landscape in this country and the broader region. Consequently, this study aimed to evaluate (1) the extent of plate waste in Lebanese hospitals, (2) the satisfaction levels of patients, and (3) the factors contributing to plate waste in the participating hospitals.

Methods

A cross-sectional study was undertaken from April 2023 to September 2023. In-patients from cardiovascular, gastrointestinal, obstetrics-gynecology (OBGYN), and surgical wards across 16 hospitals and caring centers in Lebanon were recruited for the study. The distribution of participating hospitals is illustrated in Fig. 1. These hospitals collectively accommodated 2575 occupied beds, with the number of beds per hospital ranging from 24 to 325.

Fig. 1
figure 1

Distribution of participating hospitals based on governorates. (Map template adapted from https://en.m.wikipedia.org/wiki/File:Lebanon_districts.png).

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Study participants

Patients were the primary sampling units in this study, selected through a convenience sampling strategy based on their willingness to participate and meeting eligibility criteria. The dietitian and ward nurse identified eligible patients within each ward, ensuring diversity in age and sex. Eligible patients met the following criteria: aged 18–65 years, commenced feeding within 36 h of hospital admission, not receiving enteral or parenteral nutritional support, not NPO, able to provide written consent, and spent at least one full day during their hospital stay13,14. Informed consent was obtained from all participants individually. Overall, 155 in-patients participated in the study.

Sampling strategy

We thoroughly reviewed existing literature about rates of food waste in comparable settings, which helped us estimate the right sample size for our cross-sectional study on food waste among hospital inpatients. In order to estimate a percentage in a finite population, we used the following formula15:

\(n{\text{ }} = {\text{ }}\left( {Z^{2} \times {\text{ }}P\left( {1 - P} \right)} \right)/d^{2}\)

In the above formula, “n” represents the required sample size, “Z” represents the Z-value (1.96 for a 95% confidence level), “P” represents the estimated proportion of food waste (from literature, e.g., 0.30), “d” represents the desired precision or margin of error (e.g., 0.05). Taking into account the finite population correction for our inpatient population, we adjusted the formula as follows:

\(n_{{{\text{adjusted}}}} = n/\left( {1{\text{ }} + {\text{ }}\left( {\left( {n - 1} \right)/N} \right)} \right)\)

where “N” represents the total number of inpatients during the study period. Anticipating a non-response rate of [e.g., 10%], the sample size was further adjusted:

\(n_{{{\text{final}}}} = {\text{ }}n_{{{\text{adjusted}}}} /\left( {1 - {\text{ }}non - response{\text{ }}rate} \right)\)

Based on the above calculations and adjustments, the final sample size needed was 120 patients. To be on the safe side, we added 35 patients. The total sample size (n = 155) was deemed adequate to provide reliable and generalizable results within the context of our study.

Ethical considerations

The project received ethical approval from the Ethical Committee of the Lebanese American University (LAU) in Beirut, Lebanon, with approval number LAU.SAS.HHI.2023. Anonymity of respondents was ensured during data collection and analysis. Informed consent was obtained from all participants. All methods were performed in accordance with the relevant guidelines and regulations.

Data collection

Demographic, socioeconomic, clinical, and anthropometric data

Each patient’s basic demographic, socioeconomic, clinical, and anthropometric data were collected in the first section of a questionnaire16. These included the patient’s age, sex, weight and height, residency, marital status, house area, household size, number of rooms in the home, level of education, occupation, name of the ward, reason for hospital’s admission, and length of stay (LOS).

Patient’s satisfaction and perceptions related to food waste in the hospital settings

The second section of the questionnaire comprised eight questions focusing on patient satisfaction with the hospital’s food service. These questions covered the overall food service rating, food quality, menu variety, and reasons for not consuming hospital meals. Some of the questions in this section were adapted from the ‘Acute Care Hospital Foodservice Patient Satisfaction Questionnaire (ACHFPSQ)’17, a tool commonly used to assess patient satisfaction with hospital food service (see Appendix 1).

Plate waste

Plate waste, which refers to the amount of served food that is discarded, was measured in two ways: by weighing the food served and left on the plate in grams using a calibrated portable high precision electronic kitchen scale, or by visually estimating the amount of food when weighing was not applicable since some hospitals lacked a precision kitchen scale. For visual estimation, hospitals had a standard menu and portion size (grams) served to each patient. If half of the plate was wasted for example, the portion standard portion size was divided by two to get the amount wasted. The portion sizes dished up were assumed to be the same as the standard portion size in hospitals that didn’t own a calibrated scale. As for hospitals that had a calibrated scale, dietitians were asked to weigh the food before sending it to the patient then to weigh the amount discarded. Plus, the different food items on the plate were weighed separately while eliminating the weight of the plate using the precision scale of hospitals. This information was then used to calculate the plate waste (PW) using the following formula:

\(PW{\text{ }}\left( \% \right){\text{ }} = {\text{ }}\left( {Food{\text{ }}Discarded{\text{ }}/Food{\text{ }}Served} \right) \times 100\)

The appointed dietitian was responsible for measuring the weights of both served and leftover food at breakfast, lunch, dinner, and snack times for each eligible patient throughout the study duration. The plate waste was collected in the main kitchen of each hospital. Each patient had a unique code with the corresponding gender, age, ward that was used to track the patient and link it to the other data.

Plate waste was categorized and reported in several ways, including overall waste, waste by governorate, waste by area, waste by meal timing, waste by hospital ward, and waste by food group. To divide food into groups, recipes for the meals served were obtained, and the ingredients were grouped according to the principles of the Mediterranean diet. This dietary approach emphasizes the consumption of plant-based foods and healthy fats and is recognized as the top-rated diet globally18, and was identified by the National Nutrition Strategy and Action Plan conducted by the Lebanese Ministry of Public Health as the most suitable for developing standard dietary guidelines19. Food items included in every food group are shown in Supplementary Table 1.

Statistical analysis

The collected data underwent rigorous data cleansing procedures before being transferred to the Statistical Package for the Social Sciences (SPSS; Version 25.0, IBM Corp: Armonk, NY, USA) for analysis, conducted at a 95% confidence interval (P-value < 0.05 considered significant). Categorical variables such as age and sociodemographic characteristics were summarized using frequencies (N) and percentages (%), whereas continuous variables like the amount of plate waste were described using means and standard deviations (SD). Correlation of plate waste with sociodemographic characteristics and patients’ satisfaction was assessed using Pearson test. Determinants of plate waste among patients were assessed using backward linear regression and variables entered in the model were the ones having a p-value < 0.05 in the bivariate analysis.

Results

Characteristics of study participants

Of the initially eligible 180 patients, 25 were excluded due to early discharge before completing a full day at the hospital. The final study cohort comprised 155 in-patients from various wards: cardiovascular (n = 54), gastrointestinal (n = 21), obstetrics-gynecology (n = 24), and surgical (n = 56). Among the participants, 58.1% were females. Most participants hailed from the Beirut & Mount Lebanon region (n = 69, 44.5%). Table 1 summarizes the participants’ basic demographic and socioeconomic characteristics, along with information regarding their hospital stays. The mean age of the participants was 49 years (SD: 15), with the majority (81.9%) having a hospital stay duration of less than seven days. Nearly half of the participants (54.2%) fell within the 51 to 65 age group. The mean Body Mass Index (BMI) was 25.38 (SD: 5.56) for male participants and 27.68 (SD: 6.44) for females, with a significant BMI difference observed between genders (P-value = 0.048).

Most participants (75.5%) had a household monthly income of less than USD 500. Almost half of the participants (51%) had a crowding index below 1. The crowding index is calculated by dividing the number of people living in a household by the number of rooms in the house (excluding bathrooms, balconies, porches, foyers, hallways, and half-rooms); values above 1 indicate that a household is crowded, and eventually has a lower socioeconomic status20.

Table 1 Sociodemographic characteristics, hospital stay information, and anthropometric characteristics of the study population, overall and by gender.
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Plate waste magnitude

Quantification of plate waste

A total of 1,094 meals (202 breakfasts, 258 lunches, 229 dinners, and 405 snacks) were examined. The mean daily served food was 1.24 kg (SD: 0.43) per hospital bed per day, with 0.39 kg (SD: 0.25) being discarded per bed, amounting to 31.4% waste of the total food served. Extrapolating this to the 16 participating hospitals with 2575 staffed beds, the estimated annual waste was 366.42 tonnes.

When categorized by areas (Fig. 2a), hospitals located in rural areas (n = 3) exhibited a higher mean waste, equivalent to 0.429 kg (SD: 0.458) per hospital bed per day, compared to those in urban areas (n = 13), which had a mean waste of 0.379 kg per hospital bed per day (SD: 0.211); however, no significant difference was found in the amount of waste between these areas (P-value = 0.771).

Similarly, when analyzed by governorates (Fig. 2b), the hospital in the Beqaa & Baalbek-Hermel region (n = 1) had the highest mean waste per hospital bed per day, equivalent to 0.957 kg (SD: 0.409). Conversely, hospitals in the North Lebanon & Akkar governorate (n = 4) had the lowest mean waste per hospital bed per day, amounting to 0.277 kg (SD: 0.166). Nonetheless, no significant difference was found in the amount of plate waste among governorates (P-value = 0.075).

Fig. 2
figure 2

(a) Plate waste based on areas.  (b) Plate waste based on governorates.

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Plate waste per meal timing

The mean daily wasted food amounted to 0.05 kg (SD: 0.038) for breakfast, 0.14 kg (SD: 0.091) for lunch, 0.13 kg (SD: 0.112) for dinner, and 0.06 kg (SD: 0.082) for snacks. Notably, lunch had the highest mean daily plate waste percentage, representing 37% of the total wasted weight, followed by dinner (34%), snacks (16%), while breakfast had the lowest mean daily plate waste percentage, accounting for only 13% of the total wasted weight.

Although no significant difference (P-value > 0.05) was found for plate waste at breakfast, lunch, and dinner, a notable disparity in the amount of plate waste at snacks was observed (P-value < 0.001).

Plate waste per hospital ward

The daily mean plate waste varied across different hospital wards, with averages of 0.32 kg (SD: 0.316) in the cardiovascular ward, 0.40 kg (SD: 0.403) in the gastrointestinal ward, 0.41 kg (SD: 0.379) in the OBGYN ward, and 0.40 kg (SD: 0.417) in the surgical ward. Interestingly, the OBGYN ward exhibited the highest mean daily food waste, whereas the cardiovascular ward had the lowest; however, no significant difference was observed in plate waste among the studied wards (P-value = 0.633).

Plate waste per food group

The ‘vegetables’ group emerged as the most discarded food group, with over half of the served amount going to waste. ‘Eggs’ and ‘grains and cereals’ were the least discarded food groups in our study (Table 2). Standard serving weights in grams are shown in Supplementary Table 2.

Table 2 Percentage wasted from each food group.
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Determinants of plate waste in hospital settings

Patient satisfaction according to various factors

Patients’ satisfaction with the hospitals’ food service is based on many factors, as summarized in Table 3. Concerning food quality, the majority of participants (78.1%) rated the quality as good. In addition, the majority perceive eating at hospitals as important (83.2%), 93.5% reported that food is always safe and handled in a disciplined manner. Additionally, 81.9% rated menu variety at hospitals as good and 96.8% reported that the portion size served is either sufficient or abundant for them. Moreover, meal timing was perceived as appropriate by 85.8% of participants. Overall, 89% of participants rated the food service in hospitals as ‘good’.

Table 3 Patient’s satisfaction regarding hospitals’ food service, overall and by gender.
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Determinants of plate waste

Variables correlated with plate waste are shown in Supplementary Table 3. These variables were entered in the model (backward linear regression) and results are shown in Table 4. Determinants of plate waste in our study were governorate (β= −0.18, p-value = 0.019), with higher waste observed in participants from Beirut & Mount Lebanon compared with participants from other governorates; food quality (β= −0.17, p-value = 0.049), with waste being higher in participants who rated quality as poor compared with those who rated quality as sufficient or good.

Table 4 Determinants of plate waste.
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Reasons for not consuming hospital meals

Figure 3 summarizes the various reasons for not consuming hospital meals among study participants. Nearly half of the participants (47.7%) cited low appetite as the primary reason for not consuming meals during their hospital stay, while one-third (32.9%) attributed it to having different eating habits. Interestingly, a significant gender difference was observed in reporting the feeling of satiety as the reason for not consuming meals (P-value = 0.025). However, none of the assessed reasons were significantly correlated with plate waste or identified as determinants of plate waste.

Fig. 3
figure 3

Reasons for not consuming hospital meals among study participants, overall and by gender.

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Discussion

Plate waste quantification

This study represents the first comprehensive assessment conducted in Lebanon to quantify plate waste in hospital settings, explore its determinants, and gauge patients’ satisfaction with hospital food service. Our findings indicate that hospitals in rural areas generate more waste than their urban counterparts, echoing similar observations made by Al-Shoshan21 in Saudi Arabia. Cultural differences may play a role, as rural hospitals produce more waste.

Regarding the magnitude of plate waste, our results reveal that the mean total daily percentage of plate waste represents 31.4% of the food served. This aligns closely with findings from a study conducted in Iran by Simzari et al.13, where the mean total daily percentage of plate waste was reported to be 31.3%. However, our results diverge from studies conducted in other regions. For instance, research conducted in Qatar by Al-Muhannadi et al.5 found that plate waste represented 26.8% of the total amount served. At the same time, another study by Alharbi et al.22 in Saudi Arabia reported that the percentage of plate waste was 18.2% of the total amount served.

In contrast, studies in European countries reported higher mean daily percentages of plate waste. For instance, a study in the Netherlands found that 38% of the food served was wasted14, Gomes et al.23 in Portugal reported that plate waste represented 56.4% of the food served, and Schiavone et al.16 found that 41.6% of the total food served was wasted in Italy. Similarly, studies in Malaysia by Jamhuri et al.24 and in Iran by Anari et al.25 reported even higher percentages, with waste representing 41.9% and 50.1% of the total amount served, respectively.

Plate waste per meal timing

Our study revealed that the highest mean daily waste occurred during lunchtime, with 0.146 kg per hospital bed per day, representing 37% of the total waste weight. This finding closely aligns with the results reported by Simzari et al.13 in Iran, where lunchtime plate waste accounted for 37.7% of the waste weight. Similarly, a study conducted in Malaysia by Razalli et al.26 found that the highest waste occurred during lunchtime. However, our results differ from those of other studies. For example, Al-Muhannadi et al. in Qatar and Alharbi et al. in Saudi Arabia5,22 reported higher plate waste during dinner. Such variations in findings could be attributed to factors such as the timing of meal service, portion sizes, or the specific patient care protocols implemented in different hospital settings.

Plate waste per hospital ward

Our findings indicated that the OBGYN ward had the highest waste, followed by the gastrointestinal and surgical wards, with the cardiovascular ward having the lowest. This order is consistent with a study conducted by Dias Ferreira et al.27 in Portugal, where the gastrointestinal ward had the highest waste, followed by the surgical and cardiovascular wards. However, our results contrast with a study conducted by Dehnavi et al.28 in Iran, which found that the cardiac ward had the highest waste compared to the other wards. These differences in findings could be due to variations in hospital practices, patient demographics, or cultural factors influencing food consumption patterns.

Plate waste per food group

According to our findings, vegetables emerged as the most wasted food group, accounting for 55% of the served amount. This trend aligns with a study conducted by Anari et al.29 in Iran, which highlighted that cooked vegetables and bread are more likely to be discarded by patients than meat, fish, and poultry. Similarly, studies by Jamhuri et al.24 in West Asia and Schiavone et al.16 in Italy also identified vegetables as the most wasted group. Additionally, Díaz & García30 observed in a study in Spain that in-patients generally exhibit low acceptance for vegetables, while desserts are widely accepted, a pattern consistent with our findings. Conversely, a study in Malaysia reported contrasting results, indicating that protein-rich foods are the most commonly discarded items26. Vegetables being wasted in high amount compared to ther food groups might be due to the type of vegetables served or even the way of serving (raw, cooked) and can be affected by patients’ preferences, highlighting the importance of assessing waste from this perspective in hospital settings.

Patient satisfaction and determinants of plate waste

Our findings indicated that the majority expressed satisfaction with the overall hospital food service, with 99.6% rating the foodservice as sufficient or good. In contrast, lower satisfaction rates were observed in various international studies. For instance, in East Malaysia, only 85% of participants found the hospital food service acceptable31. Similarly, studies conducted in the Netherlands, Italy, and Egypt reported satisfaction rates of 83%, 76%, and approximately 45%, respectively14,16,32. Interestingly, our analysis revealed a significant correlation between food service satisfaction and plate waste (r=-0.188, p-value = 0.019), consistent with findings from the study conducted in Italy16. However, in a study done in East Malaysia by Aminuddin et al.31, there was no correlation between these two variables.

In addition to satisfaction, several factors contribute to plate waste, including patients’ health status, food and menu quality issues, service problems, and environmental factors33. Our findings align with this notion, with low appetite emerging as the most common reason for not consuming hospital meals, followed by different eating habits, a feeling of satiety, poor food quality, health conditions, lack of food variety, and hospital environment. This trend is consistent with findings from various international studies. For instance, a study conducted in the United Kingdom identified low appetite as the primary reason for meal avoidance among hospital patients, reported by 40% of participants6. Similarly, in the United States and the Netherlands, loss of appetite was cited as the main cause of plate waste14,34. Illness-induced changes in appetite leading to reduced food intake are predictable outcomes. Factors such as nausea, dry mouth, and unwillingness to eat in Iran contributed to increased plate waste13.

Various other reasons for plate waste have been identified in different studies. For example, in Saudi Arabia, variations in meal service systems were suggested as potential causes of plate waste22. Similarly, factors related to food preparation, delivery, and meal ordering, including portion size choices, menu information tools, and monitoring, were highlighted as contributors to plate waste in Denmark35. Remarkably, our study in Lebanon reflects similar reasons for hospital plate waste observed in these countries.

Studies assessing the determinants of plate waste in the literature are limited, with most discussing potential reasons for plate waste. Our study revealed that governorate and food quality are significant determinants of plate waste in hospital settings. Specifically, we found that plate waste increases with lower food quality. Our findings align with existing literature. For instance, a systematic review conducted in Indonesian hospitals identified food quality as a determinant of plate waste, consistent with our findings36. It is however noteworthy that there are discrepancies in findings across studies. For example, a study in Malaysia26 reported menu variety as a determinant of plate waste, which was not observed in our study. Such variations underscore the complexity of factors influencing patients’ satisfaction and eventually plate waste, and highlight the importance of context-specific investigations.

In addition to food quality, participants from hospitals located in Beirut and Mount Lebanon governorate were shown to have higher waste compared with participants in hospitals from other governorates, which can be due to the fact that two of the three hospitals in our study located in rural areas belonged to this governorate which might explain the higher waste, as hospitals in rural areas generate more waste21. In addition, hospitals in this governorate provide unique services to patients and therefore can have patients from different areas and cultures who might have different food preferences.

Based on the determinants identified in our study, we recommend that hospitals’ food services should aim at prioritizing the quality and presentation of food, which may enhance the appeal and acceptability of meals, ultimately reducing plate waste. In addition, understanding which food groups are most wasted in general, and which items are wasted in specific, can serve as an effective approach in reducing plate waste.

Strengths and limitations

When it comes to food waste in hospitals in the eastern Mediterranean region, a review on hospital food waste quantification, management and assessment strategies was published in 202437. Furthermore, a study on food waste management in Lebanese hospital food services was recently published in38. Our groundbreaking study represents the first comprehensive investigation into the quantity of plate waste generated at hospitals in Lebanon, uniquely analyzing it from the patient’s perspective to elucidate the determinants of this waste. Given that previous research on plate waste has predominantly focused on household and restaurant settings, our study provides valuable insights into a sector that has not yet been thoroughly assessed in the country, thus contributing significantly to the existing literature.

However, it is important to acknowledge certain limitations of our study. As a cross-sectional study, it is constrained in its ability to establish a cause-and-effect relationship. Additionally, some governorates, such as Akkar and Beqaa/Baalbek-Hermel, were not adequately represented in the study sample, potentially limiting the generalizability of the findings to these regions. Moreover, some hospitals did not own calibrated scales to measure the plate waste so we relied on visual estimation to estimate the plate waste which is subject to inaccuracies.

Conclusion

This study underscores the importance of addressing patient satisfaction and plate waste within Lebanese hospitals. Factors such as low appetite, differing eating habits, feelings of satiety, and poor food quality emerged as primary reasons for patients not consuming hospital meals. The issue of plate waste is a significant and widespread concern, impacting both the environment and human health. However, there is a notable lack of awareness and information regarding the extent of plate waste within Lebanese hospital settings.

The quantification of plate waste in hospitals highlighted by this study emphasizes the urgent need for further research. Greater insights into the factors contributing to plate waste within hospital environments are essential for developing effective strategies to reduce waste. This study serves as a call to action for researchers, policymakers, and healthcare providers to prioritize efforts to address plate waste within the hospital sector. It highlights that the challenge of palte waste in hospitals is comparable to other sectors and warrants concerted attention and action.