Study design: A cross-sectional study will be carried out in medical and surgical wards of three general hospitals in Tehran, Iran, including Shohada-ye-Tajrish, Shahid Modarres, and Emam-Hossein, all belong to Shahid Beheshti University of Medical Sciences. This study aims to: (i) assess malnutrition and nutritional intake of patients, (ii) measure plate food waste and estimate its cost, (iii) identify the reasons for wasting food by patients (Figure 1).
Calculation of sample size: Considering the effect size of 0.25 and the power of 90%, the sample size will be 171 patients, as calculated using G* Power software (30).
Subjects: We will consequently enroll adult inpatients hospitalized in medical and surgical wards of three general hospitals in the study until fulfillment of the sample size. Following criteria will be used for enrolment:
Inclusion criteria: Hospitalization in medical or surgical ward, age≥ 19 years, consumption of hospital food, i.e. food prepared in hospital's kitchen and distributed by serving staff, and patient's satisfaction to participate in the study.
Non-Inclusion criteria: Pregnancy, unconsciousness, or disability to eat by themselves.
Exclusion criteria: Diet transition to liquid or soft diet, enteral or parenteral feeding or NPO (nil per oral), transferring to another wards (except medical and surgical) or Intensive Care Unit (ICU), discharge from hospital or death, lack of plate return to the kitchen for any reason.
Ethical considerations: The Ethics Committee of National Nutrition and Food Technology Research Institute (NNFTRI) approved the study protocol (ethical code: IR.SBMU.NNFTRI.REC.1398.073; Approval Date: 2020-01-05). Due to the cross-sectional and observational nature of the study, we will implement no intervention and only current malnutrition status, food intake and reasons to waste food will be assessed. Before initiation, patients will declare their consent to enter the study through signing a written testimonial.
Data collection and variables: Data will be collected in several parts:
1. Demographic data: A socio-demographic questionnaire, including age, sex, education, marital status, cause of hospitalization, disease history, length of stay, smoking status and current drugs and supplements use will be fulfilled for each participant.
2. Anthropometric measures: A trained nutritionist will take anthropometric measures. Patients' weights will be measured using a calibrated digital scale with the accuracy of 100 gram (g) (Seca, model 840, Maximum: 140 kg, Hamburg, Germany). In case of movement restriction (due to heavy surgeries, fractions, paralysis, etc.), weights will be recorded as self-reported by the patient. For patients with edema, the physician will determine the weight. Heights will be measured in standing position with minimum cloths and the accuracy of 0.1 centimeter (cm) (Seca, Hamburg, Germany). If direct measurement is not feasible because of the patient's condition, indirect methods will be applied to estimate heights, either using ulna length (31) or preferably using knee height by a non-flexible tape-measure (32, 33). To estimate height using ulna length, the distance between the point of elbow (olecranon process) and the midpoint of prominent bone of the wrist (styloid process), possibly from left side, will be measured and rounded to the nearest 0.5 cm and height will be estimated using the standard method (31). Knee height will also be measured in supine lying position using a tape meter, by holding both knee and ankle at 90-degree angles (32, 33) and height will be calculated using the following formulas:
Heights for males (cm): 64.19 – (0.04 × age) + (2.02 × knee height)
Heights for females (cm): 84.88 – (0.24 × age) + (1.83 × knee height)
3. Quantity of plate food waste: Food waste will be measured during two main meals (breakfast and lunch) and snacks (in the morning and evening). Food ingredients will be extracted from the hospital’s food guide and validated by asking the chef or food preparing staff. A trained nutritionist will record the average portion size by weighing at least two sample dishes in each meal using a portable digital scale with the accuracy of 1 g. Foods served in trays, dishes or disposable containers will be distributed among the due wards, i.e. medical and surgical wards, through hospital’s food delivery system and leftovers will be returned to the weighing zone. Then, total amount of plate food waste will be measured and calculated per studied patient, meal (breakfast, lunch, snacks) and ward as the following:
WP: percent of daily wasted food per patient
n: total number of the studied patients
i: refers to the specific daily measurement for each patient
WF: weight of daily wasted food for each patient in each meal (gr)
FP: average weight of the food portion in each meal in the day of measurement (gr)
j: refers to the specific meal including 1=breakfast, 2=snacks, and 3=lunch
WM: percent of daily wasted food per meal
WW: percent of daily wasted food per ward
nd: total number of eligible patients in each ward in the day of measurement
d: total number of the measurement days
4. Cost of food waste: A nutritionist will extract food ingredient by asking the chef. After measuring the portion size, the total price of a usual portion will be estimated by asking food provider who routinely buys raw materials for the kitchen. This will not include procedure expenses, like energy or employees’ salary cost. Cost of food waste will be calculated and reported per studied patient, meal (breakfast, lunch, snacks) and ward using the following equations:
CWP: cost of wasted food per patient in the day of measurement (Rial)
TCM: average total cost of all meals in a day (Rial)
CM: cost of food portion in each meal in the day of measurement (Rial)
k: refer to the day of measurement
CWM: cost of wasted food per meal in the day of measurement (Rial)
CEM: average cost of each meal in a day (Rial)
CWW: cost of daily wasted food per ward (Rial)
N: average daily number of eligible patients in each ward during the study period
All costs of food waste will be reported in the national currency and will be finally converted to US dollar using the average exchange rate during the study period.
5. Nutritional value of wasted food: The amount of wasted food will be entered into Nutritionist IV software (First Data Bank Inc., San Bruno, CA, 1997) to extract energy, protein and micronutrients content (vitamin A and D) of wasted food for each patient.
6. Nutritional intake and requirement: The mean daily energy and protein intakes will be extracted from a 24-hour food recall using Nutritionist IV software (First Data Bank Inc., San Bruno, CA, 1997) modified for Iranians foods’ ingredients. The mean daily energy and protein intake will be reported for medical and surgical wards of studied hospitals. Resting metabolic rate (RMR) will be calculated for each patient according to age, weight and sex using equation developed for Iranians for patients 19-59 years old (34) or Mifflin equation for those ≥60 years old (35) (Table 1). Finally, total energy expenditure (TEE) will be calculated considering injury factors (IF) and activity factors (AF) (36) (Table 2) as:
7. Malnutrition assessment: We will assess subjective and objective malnutrition for each eligible patient as the following:
7.1 Subjective malnutrition: Subjective malnutrition will be evaluated using subjective tools: subjective global assessment (SGA) tool for adults 19-65 years old (37) and mini-nutritional assessment (MNA) tool for adults ≥ 65 years old (38).
7.2 Objective malnutrition: Protein malnutrition will be evaluated by measuring serum albumin, prealbumin (PAB) and total protein using standard methods. If the concentrations of all three serum proteins are low, it will signify protein malnutrition (39). Micronutrient malnutrition will be assessed by assessing vitamins A and D status using serum retinol and 25-hydroxycalciferol [25(OH)D] determination, respectively.
8. Biochemical analyses:
Blood sample preparation: The day after measuring food waste, 10 mL venous blood sample will be drawn from patients. The samples will be immediately sent to the Laboratory of Nutrition Research, NNFTRI, in a cold box and serums will be separated by centrifuging at 800 g for 20 min at room temperature and will be stored at -70 ºC until the day of biochemical examinations.
The following biochemical tests will be employed to assess selected micronutrient status (vitamins A and D), protein malnutrition (albumin, PAB and total protein), anti-oxidative defense (total antioxidant capacity [TAC], malondialdehyde [MDA] and β-Carotene), and inflammatory status of the patients (highly sensitive C reactive protein [hs-CRP]):
8.1 Serum retinol:, To assess vitamin A status, serum retinol will be measured using high performance liquid chromatography (HPLC) as originally described (40) with some minor modifications (41). In this study, serum concentrations 0.35-0.70 μmol/L (10-20 μg/dL) will be considered as marginal vitamin A deficiency, <0.35 μmol/L (10 μg/dL) as vitamin A deficiency, >1.05 μmol/L (30 μg/dL) as adequate status and > 3.49 μmol/L (100 μg/dL) as hypervitaminosis A (42-44).
8.2 Serum β-Carotene: Serum concentrations of β-carotene will be assayed using HPLC (45). Actually, serum retinol and β-carotene will be determined simultaneously.
8.3 Serum 25(OH)D: Vitamin D status will be determined by measuring circulating 25(OH)D concentrations using enzyme immunoassay (EIA) method (Padtan Gostar Isar®, Tehran, Iran). In this study, serum 25(OH)D concentrations > 50 nmol (20 ng/mL) will be considered as sufficiency, 27.5-50 nmol (11-20 ng/mL) as insufficiency and < 27.5 noml/L (11 ng/mL) as deficiency (46).
8.4 Serum MDA: Serum MDA, as a biomarker of oxidative stress, will be assessed by measuring thiobarbituric acid reactive substances (TBARS), as described elsewhere (47, 48).
8.5 Serum TAC: TAC will be evaluated using 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) reagent and bovine serum albumin as standard (49).
8.6 Serum hs-CRP: It will be measured using EIA (Pars Azmoon, Tehran, Iran). In this study, serum hs-CRP will be interpreted as following (50): < 3.0 mg/L: normal; 3-10 mg/L: minor elevation; 10 to 100 mg/L: moderate elevation; > 100 mg/L: marked elevation; and > 500 mg/L: severe elevation.
8.7 Serum albumin: We will measure serum albumin using the specific commercial kit (Pars Azmun, Iran). Concentrations 5-5.0 g/dL will be considered normal (51).
8.8 Serum PAB: Serum pre-albumin will be measured through turbidimetric immunoassay method using commercial kit (Zellbio, Germany). Concentrations between 15 and 35 mg/dL will be considered normal (52).
8.9 Serum total protein: Serum total protein will be measured using a specific commercial kit (Pars Azmun, Iran). The normal range for total protein is between 6.0 to 8.4 g/dL (51).
9. Qualitative study:
9.1 Participants: To collect data regarding possible reasons for wasting food, we will conduct a qualitative study with nurses, nutritionists, food staff (i.e. chef, chef assistant, and delivery staff), food providers, hospital managers and patients hospitalized in medical and surgical wards of the studied hospitals.
9.2 Methods: The qualitative study includes several individual “In-depth’’ interviews. The interviews will be guided by a ‘‘Topic Guide’’ (Table 3). After the clarification of the objectives and procedure of the qualitative study for the participants, they will be allowed to read and sign the written consent. The topic Guide will be developed based on objectives of the study and target groups. It will be a “semi-structured” questionnaire which means the questions will not be asked necessarily in a specific order. There will be six target groups including nurses, dieticians, food providers, patients. hospital managers and food staff for whom the topic guide will be prepared. It will contain some main and probing questions about reasons for wasting plate-food by patients. Depending on the question, some complementary questions will be asked. Clear words and neutral sentences will be used to make it understandable for interviewees, but to not affect their responses. The interviews will be continued until “data saturation” in which no novel responses will be given. At this point, the researcher will stop the sampling (53). Each interview will last 30 to 60 minutes and will be held in a suitable calm place in the hospitals. The research team will consist of a facilitator and at least one note-taker. At the beginning of the interview, the facilitator will introduce herself and clarify the aim and procedure of the study. All the participants’ answers and cues (body languages) in addition to date and place of the interview will be recorded by the note-taker(s). To avoid missing any details, the interviews will be recorded by a voice-recorder simultaneously by the participants’ permission. A member of the research team qualified in qualitative studies as observer will observe some of the interviews by random. She will assess ‘quality assurance’ through auditing the processes of interviewing, coding, analysis and interpretation of data to control reliability and validity of data. To ensure that the interviewer has an accurate understanding of the interviewee’s responses, she will restate her perception of their answers during and at the end of the interview and will ask them to correct her perception if necessary (member check). Furthermore, by collecting answers from different sources, e.g. from dissimilar participant groups, the validity of the data will be assured (triangulation). During coding stage, a part of the interviews (e.g. 20-30% of total) will be separately coded by another member of the research team. The percentage of agreement will be calculated and reported for inter and intra raters, as well. Before starting the fieldwork, some pilot interviews will be conducted in some target groups to resolveany inadequacies.
9.3 Qualitative data analysis: In this study, we will collect, analyze and classify data, simultaneously. The approach of the study will be ‘‘content analysis’’ (54). To begin the analysis, all notes will be sent to MAXQDA software (Version 10, VERBI Software Consult. Sozialforschung. GmbH, Berlin, Germany). To explore emerging themes and subthemes the notes will be read many times carefully by the research team, followed by organizing (coding) data based on the main objectives of the study. Then, frequency of each theme will be determined and categories will be developed based on the most frequent themes. Finally, the research team will discuss about emerging the themes and core categories. To calculate the percentage of agreements (between and within coders), kappa test will be used.
10. Statistical analyses: Quantitative and qualitative data of food waste and nutritional status will be analyzed using SPSS software (version 21, SPSS Inc., Chicago, IL, USA). Quantitative data for variables like quantity and cost of food waste will be reported as mean ± standard deviation (SD), and qualitative data, like malnutrition status or micronutrients deficiency, will be expressed as percent or proportion. Shapiro-Wilk test will be used for evaluating the normality of data distribution. Biochemical results will be compared among different malnutrition categories, wards and hospitals using one-way analysis of variance (ANOVA) or the equivalent non-parametric test. Finally, data analysis by linear logistic regression will propose a model using P-value less than 0.05 as significant.
Data of the qualitative study on reasons for wasting foods will be analyzed using MAXQDA software (Version 10, VERBI Software Consult. Sozialforschung. GmbH, Berlin, Germany) and reported as themes and subthemes and categories. Finally, the main influencing factors affecting hospital food waste will be explored and reported.