“A cross-category analysis of the effectiveness of an intervention in food preparation stage in reducing consumers’ food waste”
MSc in Marketing Management Master Thesis
First Supervisor: Dr. Jenny Van Doorn Second Supervisor: Dr. Marit Drijhout
Alberto Folini S2942909
Muurstraat 13 A, 9712EM Groningen(NL)
Email: alberto.folini@gmail.com
Abstract ... 3
1. Introduction ... 4
2. Literature review ... 7
2.1 Household food waste ... 7
2.2 Determinants of household food waste ... 8
2.3 Food preparation: trends and impact on food waste ... 9
2.4 Food portioning: plate waste problem ... 9
2.5 Cross-category effects ... 10
3. Conceptual model and Hypotheses ... 11
Hypotheses ... 13
3.1 Effects of the introduction of the Eetmaatje on food waste in pasta and rice categories ... 13
3.2 Effects of the introduction of the Eetmaatje on food waste in other categories of food ... 13
3. 3 Impact of food preparation ability on the effectiveness of the intervention ... 14
4. Methodology ... 15
4.1 Data collection ... 15
4.2 Study design ... 15
4.3 Construct measurement ... 16
4.4 Questionnaire structure ... 17
4.5 Reliability analysis ... 17
5. Results ... 19
5.1 Descriptive statistics ... 19
5.2 Hypotheses testing ... 21
5.3 Hypotheses Validation ... 25
6. Discussion ... 26
6.1 Managerial implications ... 28
6.2 Limitations and further research ... 28
Abstract
This paper presents the results of a field experiment conducted to test the influence of an intervention in food preparation stage, precisely in food portioning stage, as well as participants’ food preparation ability, on the amount of household food waste in 38 Dutch households. More precisely, this research is one of the first to investigate the effect of a measuring cup, in this case named Eetmaatje, on the generated amount of household food waste.
The research data were collected through a 1-week food waste diary study accompanied by a background questionnaire. Even if, on average, people who received the Eetmaatje wasted less, it was established that the introduction of a measuring cup is not strictly correlated with a reduction in the amount of food waste.
Key words: Food waste, food portions, measuring cup, food preparation skills
1. Introduction
In the last few decades food waste has become one of the major contemporary global issue. It has been recently estimated that each year one third, 1.32 billion metric tonnes, of food produced for human consumption is lost or wasted globally. The Environmental impact of food production and consumption is becoming a serious problem with numerous repercussions in term of pollutant emissions, exploitation of natural resources and also world hunger and malnutrition (Gustavsson, et al., 2011). In industrialized countries, the largest share of food waste occurs at the consumer level (Gustavsson et al. 2011) and while a large part of food lost earlier in the supply chain is at least used, for instance, to feed animals, household food waste for the most part ends up in the trash, causing additional costs and environmental impact (Gustavsson et al., 2011; Soethoudt and Timmermans, 2013).
In high- income countries, such as the Netherlands, much of the food is wasted as a consequence of oversupply or wrong food preparation and cooking behaviours (Food and Agriculture Organization [FAO], 2013; Parfit et al., 2010). This amount of food waste not only represents a monetary loss for households, but also as it wastes natural resources, affects food availability for developing countries, and generates greenhouse gas (Stuart 2009).
It is evident that food waste is an important and global issue, which needs to be studied and solved.
However, current academic literature provides only little insight regarding the factors that influence households’ food waste behaviours. Past studies attempted to explain, for example, which food categories are most susceptible of being wasted (Quested & Johnson 2009) or how consumers feel about their food disposal behaviour (Evans, 2011; Lyndhurst et al., 2007), but the drivers that lead to these food waste behaviours remain scarcely researched. Therefore extensive research from a household perspective is necessary in order to gain a clear view of the processes that caused the waste of edible food products.
Other previous research has demonstrated that ones of the most common causes of edible food wastage are households’ cooking or serving too big portions, time constraints regarding food preparation as well as a lack of consumers awareness regarding their contribution to food waste (Evans, 2012; Koivapuro et al., 2012).
The central aim of my study is to explore some of those causes, especially focusing on portions and food preparation, testing the effectiveness of an intervention in these stages. To accomplish that, a group of consumers will receive a tool developed by the Dutch nutrition foundation and named Eetmaatje (see appendix). This object is a simple plastic measuring cup projected to help households
with their pasta and rice portions.
Scholars agree on preparing and serving too much food are reasons contributing largely to households’ food waste (Exodus 2007; Quested et al., 2013).
The first research question developed is:
RQ 1: “ To what extent can the introduction of the Eetmaatje influence consumers’ food waste regarding pasta and rice categories? “
Considering that portioning is the phase where food is prepared for being cooked, it can be assumed that in this phase different categories of food are involved and consequently a large amount of the food consumed and part of the one wasted is determined.
This paper will not only focus on pasta and rice categories but aims to understand if the intervention can also influence the quantity wasted in other categories of food. In fact the second research question developed is:
“ To what extent can the introduction of the Eetmaatje influence consumers’ food waste regarding other categories of food involved in the food preparation stage? “
Furthermore, the central belief behind this research is that through interventions based on food preparation, portions and disposal, institutions can raise awareness about this crucial issue and reduce levels of household food waste how is previously demonstrated in the research conducted by Clarke, Schweitzer and Roto in 2014. The food preparation ability of the participants will be analysed in order to understand if it can influence the effectiveness of the intervention. In fact, according to Byrd-Bredbenner, people with low food preparation ability are usually more affected from intervention aimed to improve food preparation and portioning skills. So, the third research question of this study is:
“ To what extent can consumers’ food preparation knowledge and skills influence the effectiveness of the intervention? “
Admittedly, there is a lack of public awareness about the magnitude of the issue and what can be done to reduce food waste in this stage. It is clear that enhance consumers’ food portioning ability has become fundamental to contrast the alarming trend of the last years. This critical issue will be
analysed in deep in the next literature review section.
The main goal of this study is to analyse the influence of a measuring cup on the generation of avoidable food waste in 38 Dutch households. The focus is on describing if the presence of the Eetmaatje can be determinant to explain the differences in households’ quantity of food wasted.
Finally, the aim of the current research can be resumed in the following problem statement:
“ Can an intervention in the portioning stage influences household food waste in different categories of food? “
2. Literature review
The following chapter briefly explores and describes the already existing literature about food waste with an interested focus on the household dimension of this phenomenon. In order to summaries what is the importance of food preparation stage on household food waste and highlight the role of food portions sizes regarding consumers’ health and food waste reduction past research will be reviewed and discussed.
I want to start this literature review with a quote that explain in a clear way the actual situation:
“The UK, US and Europe have nearly twice as much food as is required by the nutritional needs of their populations. Up to half the entire food supply is wasted between the farm and the fork” (Stuart, 2009).
Food waste is a topic that has received attention from various researchers and activists through out the last two decades (Evans 2011 and 2012, Freedman, M.R. and Brochado, C. 2010, Gustavsson 2011), aiming at understanding and an attempt at reducing and preventing the practice.
Furthermore, there has been evidence through research carried out, just to name a few findings, which recognize that (1) there is the need for a better understanding behind the practice of food waste, (2) that it is essential to enhance communication along the food chain and that (3) there is the necessity to intensify the collaboration among all actors of the food chain (Shanklin, 1993; Parfitt et al., 2010; Sonnino & McWilliam, 2011) if reducing food waste is achieved.
2.1 Household food waste
The losses occurring at the end of the supply chain, at retailer or consumer level are called “food waste” (Parfitt et al., 2010). This research will take in account this final part in the food supply chain and investigate the reasons of households’ food waste as a consequence of consumer behaviour.
Previous research have found that within the food supply chain consumers’ can be identified as main contributors to food waste, as households produce more food waste than, for example, grocery retail stores or manufacturers (Griffin et al. 2009, Quested & Johnson 2009).
In the Netherlands, the Dutch consumer throw away on average solid food for 47 kilos each year with an approximate overall value of 2.5 billion € per year. This is equivalent to 340€ per household and 150€ per person. Comparatively, 2 billion € are discarded by food manufactures and supermarkets every year (Government of the Netherlands, 2013; Ministry of Economic Affairs 2014).
Of these 47 kilos, 32 kilos disappear via household waste, and an estimated 15 kilos via alternative flows. Some nine kilos of the food we each waste in the Netherlands every year are prepared products, either cooked or baked. About five kilos remain untouched in the packaging or are
unpeeled fruit and vegetables. In total, Dutch consumers waste about 14% of their solid food.
(Netherlands nutrition Center, 2014)
However, in other countries the amount is even higher, in the UK for example an average family wasting food equalling 480£ per year (Quested & Johnson 2009). In Australia $616 (Baker et al., 2009) and in US at least $590 (Jones, 2005). Globally, minimizing food waste is therefore an important component of food chain responsibility.
Finally, consumer food waste can take place during the acquisition, the preparation as well as during the consumption stage of food (Griffin et al. 2009). Evans in 2011 stated that food wasted is a consequence of the interaction between different household dynamics and, therefore, this issue should not be analysed as a single component but as the result of multiple components that together cause the amount of food that is wasted.
2.2 Determinants of household food waste
Different reasons for household food waste were revealed by previous research. Consumers’
purchase and consumption behaviour, time pressure as well as lack of cooking and food preparation skills are determinant causes of food waste (Evans, 2012; Graham-Rowe, Jessop & Sparks, 2014).
Evans, in 2012, found that one of the major determinants of large amount of household food waste could be identified in consumers’ over purchasing behaviours. This can be explained by the fact that every household usually purchases more food products than needed and, as a consequence, wastes the majority of this surplus. The reasons of this phenomenon can be explained by various consumer behaviours, such as, households’ negligence of planning meals in advance, inability of controlling the quantities of food needed before going to the supermarket and also by consumers’ wrong shopping routines. (Chandon & Wansink, 2006; Evans 2012; Quested, et al. 2013; Stefan et al., 2013).
Not only over purchasing is responsible for large amounts of household food waste. Preparing, cooking and serving much more food than needed determine a large part of households wasted food items (Exodus 2007; Quested & Johnson 2009; Evans, 2012).
Moreover, the idea that food waste is not a problem as well as the socially accepted belief that producing food waste is “ normal “, has led in the past to higher amounts of food wasted (Graham- Rowe et al. 2014).
In addition a lack of awareness regarding the individual contribution to food waste can be observed within a large amount of households (Quested et al, 2011; Graham-Rowe et al. 2014)
However, the relationship between portioning skills and household food waste has not been often researched in the past and so a stable connection cannot be assumed.
2.3 Food preparation: trends and impact on food waste
In recent years, debate has been developing worldwide about the state of contemporary food skills.
Pre-prepared foods and modern technologies have changed how consumers interact with food and engage in household food work. Some experts argue that due to these changes, home cooking and preparation skills are in decline (Ripe C.; 1993 and Ritzer G.; 1996) and others argue that they are undergoing a transition (Lang and Caraher; 2001, Short F.; 2003)
In the past, cooking and preparation skills were routinely taught by parents or learned at school.
Research supports the conclusion that individuals who lack cooking and preparation skills are more likely to regularly eat out or to eat convenience meals. (Soliah, Walter and Jones; 2012).
Other previous cross-sectional studies have suggested a relationship between food preparation knowledge or skills and consumption of particular foods. (Reicks, et al.; 2014)
Moreover, it has been recently demonstrated that high levels of food waste are often linked with low food preparation and cooking skills. (Reicks et al.; 2014).
Furthermore People with low food preparation ability tendency to more buy pre–prepared foods usually have a negative impact on their health and on their overall food waste due to the impossibility to control ingredients and portions of the food bought.
Some authors suggest that today’s younger generation is not acquiring adequate food skills.
Nowadays busy daily lives and professional commitments mean that parents may be cooking less frequently at home. It is important to emphasize food skills training, both formal and informal, particularly but not only in children, as lack of such skills may hinder attempts at changing and/or improving food-related behaviour in the future. (SAFE FOOD 2014)
2.4 Food portioning: plate waste problem
In the last years some studies have tried to understand what is the relationship between the ability of making portions and the quantity of food wasted. Food waste is a complex issue with many drivers, but ever-expanding portion sizes are undoubtedly one of them. But while much attention has been paid to the resulting impacts on obesity, there has been relatively less focus on the ways in which increased portion sizes have contributed to the growing amount of food that gets wasted (Gunders 2012).
It has been demonstrated that most people are unaware of what constitutes an appropriate portion.
Because portion size is a modifiable environmental factor, it should be addressed as one of the
possible tool to prevent obesity and to reduce household food waste. One approach would be to educate people about appropriate portions and about interpreting nutrition labels. (Rolls, Morris and Roe; 2002)
Homes are not exempt from the large portion trend. The Cornell Food and Brand Lab reports that serving sizes in the Joy of Cooking cookbook have increased 33.2% since 1996 alone. That is, a recipe that used to “serve 10” now “serves 7” (or the ingredient amounts are greater for the same number of servings). In some cases, this leads to overeating. In others, it simply leads to extra food that ends up in the trash (Gunders 2012). Additionally, a research about food portion size developments in the Netherlands conducted by Steenhuis et al in 2009 has showed that trends observed are all indicating an increase in portion sizes of energy-dense food products during the past decades.
It is clear that interventions aimed to help consumers with food portions, and to revive their food preparation skills, are necessary to contrast this alarming trend and to make them more aware about the quantity of food they are used to waste.
Globally, current recommendations to reduce portion sizes target the importance of this behaviour for healthy weight maintenance but neglect to mention the positive impact on waste. Recent research has pointed out the relationships between portion size and food consumption, and related studies have also linked portion size to food waste. Portion size reductions have been shown to reduce food disposal through a lower plate waste. (Freedman, M.R. and Brochado, C. 2010)
Plate waste in households refers to the served food that remains uneaten by family members. High levels of households plate waste can contribute in a significant way to financial and environmental costs.
2.5 Cross-category effects
In the world of marketing, and especially in retail sector, cross-category affinity analysis is commonly used to perform market basket analysis, in which retailers try to understand and explain the purchase behaviour of customers. The data obtained can then be used for implementing selling strategies, sales promotions, loyalty programs, discount plans and to get a better understanding of the consumers present in the market.
At the heart of cross-category management lies a deep understanding of cross-category affinity (demand and consumption attraction between categories) analysis that helps retailers to identify the
product categories that are likely to be consumed and purchased together. (R.Bezawada, S.
Balachander, P.K. Kannan & V. Shankar; 2009).
Typically, the demand for two product categories is complementary when they are consumed together. Examples of pairs of complementary categories include toothpaste and toothbrush, cake mix and cake frosting, and pasta and pasta sauce. Prior research in this field has used both household-level (market basket) data and store level data to empirically infer these complementarities through the correlation of preferences across categories. (Shankar & Kannan 2014)
Mulhern and Leone (1991) and Walters (1991) found that sales of a brand in one category might be positively affected by promotional activity of a brand in a complementary category. Studies by Chintagunta and Haldar (1998) and Manchanda, Ansari, and Gupta (1999), in contrast, have a category-level focus. Manchanda et al. (1999) find significant effects of category-level price changes and price promotions on consumer purchase incidence probabilities across complementary categories. The study by Chintagunta and Haldar (1998) investigates whether a consumer’s purchase timing in one category is affected by purchases made in another category. They find that purchase timing is negatively related across substitute categories (i.e., the purchase in the substitute category is delayed) while a positive effect is found for complementary categories (i.e., the purchase in the complementary category occurs earlier).
Basically none of the research present in the existing literature investigated this field from the households’ food waste perspective, investigating if cross-category effects are present between the categories of food usually wasted.
3. Conceptual model and Hypotheses
The existing literature has shown that little is known regarding households’ food waste behaviours when portioning stage is involved. Additionally those researchers having studied the effects of portioning skills on food waste but not the real effectiveness of interventions in this phase.
(Freedman and Brochado, 2010)
This research aims to study in deep this stage, especially due to the fact that as literature suggests, a lack of skills in food preparation and portioning could be responsible for the creation of household food waste. (Evans, 2012; Koivupuro et al. 2012; Graham-Rowe et al., 2014).
Firstly, the study wants investigate the influence of using the Eetmaatje on the amount of pasta and rice wasted. These are the two categories of food directly involved in the usage of the Eetmaatje and
therefore, the assumption made here is that consumers who received the measuring cup will probably waste less because they will size food portions way more precisely. This assumption is made considering that household plate waste is usually due by over size portions (Gunders 2012).
Secondly, will be researched if cross-category effects will arise after the introduction of the Eetmaatje. The assumption made is that the measuring cup can influence the amount of food wasted in other categories of food. (Chintagunta & Haldar , 1998)
Finally, measuring cups are usually more useful for people with less cooking and preparation knowledge, they help especially households with low preparation skills to reduce their amount of disposed food. Hence, the assumption made is that the level of food preparation ability of the consumers involved can shape or increase the effectiveness of the intervention. (C.Byrd-Bredbenner, 2004).
In addition, the variables age, gender, monthly household income, household size, employment status as well as the working hours will be included as control variables as they are found to influence the amount of household food waste (Lyndhurst et al., 2007; Parfitt et al., 2010, Evans, 2011; Evans, 2012; Koivupuro et al., 2012)
Based on these assumptions, the following conceptual model has been established. In the following paragraphs the relationships depicted in the conceptual model will be discussed in more detail.
Hypotheses
3.1 Effects of the introduction of the Eetmaatje on food waste in pasta and rice categories For many individuals, determining how many ounces of pasta to serve themselves for dinner is a relatively low-involvement behavior that is a difficult nuisance to repeatedly and accurately monitor.
(Van Ittersum 2013)
Recent research has pointed out the relationships between portion size and food consumption, and related studies have also linked portion size to food waste. Portion size reductions have been shown to reduce food intake along with plate waste. (Freedman and Brochado, 2010)
Considering that pasta and rice are the categories directly involved in the use of the Eetmaatje, which is projected to try to reduce plate waste through helping consumers with their portions, the expected result is that consumers who will receive the measuring cup, and use it for making pasta and rice portions, will reduce the quantity of food wasted in these two categories.
If consumers start to regularly use an object like Eetmaatje this can probably have a positive impact on food waste reduction thanks to portions.
The assumption made here is that:
H1: The use of the Eetmaatje will lead to lower amounts of pasta and rice wasted
3.2 Effects of the introduction of the Eetmaatje on food waste in other categories of food
In their investigation of dependencies in the purchase and consumption behaviour of households across two product categories, Chintagunta and Haldar (1998) find that a cut in the quantity purchased and consumed in one category decreases the purchase and consumption probabilities of complementary product categories (e.g., pasta and pasta sauce).
Considering that larger cross-category effects should emerge if more categories are considered simultaneously (Leeflang et al., 2004), one of the goals of this study is to analyse if the introduction of the measuring cup will also affect the quantity wasted in other categories of food leading to food waste cross-categories effects.
Considering that they will be asked to fill a food waste diary on a daily basis and consequently that they will have the possibility to monitor their waste category after category every day, this can lead to more aware and careful consumers regarding the food waste issue.
Additionally, the report on Kitchen Canny project published by Changeworks in 2010, indicated that participants reduced their food waste arising as a result of becoming more aware of the amount of
food that they were wasting.
For example, vegetables, meat, sauce and other ingredients are often simultaneously involved in the recipes created to dress pasta and rice dishes and so can be also influenced by the introduction and usage of the measuring cup.
In order to analyse what stated in this paragraph the following hypothesis has been stated:
H2: The introduction of the Eetmaatje will reduce food waste in other categories of food
3. 3 Impact of food preparation ability on the effectiveness of the intervention
One of the goals of this study is to test if the level of the consumers’ food preparation ability can impact the effectiveness of the intervention in terms of quantity of food wasted.
Previous research have demonstrated that both consumers with poor and fair preparation ability may be more open to learning about food preparation because they realize that they could improve their knowledge and skills level and consequently waste less. (C. Byrd-Bredbenner 2004).
Following this statement I elaborate the assumption that probably people with low food preparation ability will probably be more affected from the introduction of the Eetmaatje. This will probably happens because they will realize that the measuring cup can enhance their poor food preparation ability and help them to reduce food waste through better portion sizes. (Reicks et al; 2014).
A lower effectiveness is instead expected between people with higher food preparation ability. This because there is a possibility that people with high food preparation already make right food portions. (Rolls, Morris and Roe; 2002)
In order to test if significant differences are present between people with different level of food preparation ability the following hypotheses have been developed:
H3(a): The effectiveness of the Eetmaatje in food waste in rice and pasta categories will be higher for consumers with low food preparation ability
.
H3(b): The Eetmaatje’s influence in food waste in other categories of food will be higher with people with low food preparation ability
4. Methodology
The following chapter describes the methodology through which this research will be conducted.
4.1 Data collection
This research has been conducted thanks to the authorization from the Albert Hejin management to use for two times in two different weeks one of their supermarket in Groningen. Our goal was to hand out a questionnaire and a food waste diary to a minimum of 280 consumers. This number is needed because together with the Eetmaatje other two interventions developed by the Dutch Nutrition Foundation will be analysed. Considering that a control group composed by consumers that don’t receive any tool is necessary, 70 consumers for each group should be enough to collect a consistent amount of data.
In order to test the hypotheses presented in the previous chapter, a between subjects experimental study is proposed. Data is collected through the distribution of a questionnaire and of a food waste diary. The questionnaire (see appendix 1) contains 32 questions developed in order to define an exhaustive portrait of the consumers involved in the study. The first section is dedicated to questions about the demographic details of the consumers in order to collect all the information needed for the development of effective control variables.
From the rest of the questionnaire I will take only the parts that I will need to construct my moderator, food preparation ability. The question that will be used to create a food preparation index of the consumers involved in the study is Question 19.
In order to increase the validity of the results the respondents have been randomly assigned to one of the four conditions of the study (Aronson, Wilson, & Brewer, 1998).
4.2 Study design
A questionnaire is created and it contains all the questions relevant for the study objectives (Appendix 1). For each different condition, participants receive the same questionnaire and food waste diary. To grant the validity of the experiment the questionnaire was approved by the Dutch Nutrition foundation and the fact is highlighted in the introduction section of the questionnaire. This questionnaire was developed following all the criteria needed to reach an academic consistency.
Thus, if respondents are exposed to an experiment that they don’t perceive as important and official, they will not feeling involved in the study and the results of the experiment will be affected.
The creation of a Food waste diary (see appendix 2) has been adopted because previous research (Koivupuro et al. 2012) have demonstrated that is an effective tool to collect important insight about household food waste attitudes. It is important because it simplify a lot the task assigned to the participants, making easier the collection of the data required for the experiment (quantity of food wasted for each categories).
This tool will be fundamental for my study because it allows me to analyse firstly the impact of the Eetmatje on pasta and rice category and then the cross- category effects that can arise after the use of the measuring cup.
4.3 Construct measurement
The following section shows the construct measurement. Table 2 presents the variables that are going to be measured. In order to measure the quantity of food wasted a food waste diary will be filled by consumers and analysed from me.
The following table shows all the variables with their respective scales.
Concepts Items Scale Source
Dependent variable:
Food waste
Food waste diary See appendix 2 Koivupuro and colleagues (2012)
Control variables:
Demographic
What is your gender?
What is your age?
What is your household monthly income?
What is your household size?
Govindasamy & Italia, (1999)
Moderator:
Food preparation ability
“ I can prepare a "potato au gratin".”
“ I can make my own soup.”
“ I can create a sauce.”
“ I can bake a cake by myself. ”
“ I can bake a bread by myself.”
7 point Likert scale anchored by strongly disagree to strongly agree.
( Mayers et al. 1997 )
Table 1: variables and scales
4.4 Questionnaire structure
Subsequently, respondents are asked to answer to: to demographic questions (gender, income and age), questions regarding their cooking skills, health motivation, food preparation ability, food involvement (see Appendix 1) and to fill a food waste diary during the weeks in which they will use the tool received (see Appendix 2).
In the first part of the questionnaire, respondents need to indicate their gender (Male or Female), fill the age, and select their total monthly household income ranging from: below 500 € to more than 4000 €.
In the following part of the questionnaire participants will communicate their opinions about the arguments investigated on a 7-point likert scale ranging from 1 (strongly disagree) to 7 (completely agree). This part is very important for my research because in this section will be collected insights about my moderator, food preparation ability of the consumers involved. Participants have to accurately fill the food waste diary that they received at the supermarket during all the period of the study. This diary is characterized by different sections labelled with the name of the different categories of food. For each category is asked to indicate the quantity (in grams) wasted during the period of the experiment. This is fundamental in order to understand what are the effects of the intervention across all the categories of foods and not only in the ones directly involved in the use of the tool.
4.5 Reliability analysis
The analysis entails only one scale, which is fundamental for measuring the moderator effect. In order to proceed with the statistics analyses its reliability needs to be determined. In order to analyse, if the measured items form the scale as expected, a factor analysis will be conducted on the construct of food preparation ability. This will allow, detecting whether those items measure the same construct or whether uncorrelated underlying dimensions exist (Malhotra, 2010). Additionally, a
reliability analysis is used in order to test the internal consistency of the different items forming this single variable (Malhotra, 2010). In case of reliable results, a new variable will be computed entailing the different items.
A factor analysis requires a Kaiser-Mayer-Olkin (KMO) measure of sampling adequacy in order to examine the appropriateness of the factor analysis. If the value is larger than .5 the data is expected to factor well and the factor analysis is appropriate. Secondly, the Bartlett’s test of sphericity examines the null hypothesis that the variables are uncorrelated. A significance level below .005 confirms the correlation between the variables. Thirdly, the communalities and factor loadings need to be analysed; the value for each variable should be larger than .4 for the communalities in order to ensure that the proposed factors explain a large enough percentage of the variance. Additionally the values for the factor loadings should be larger than .5 (Malhotra, 2010).
If the factor analysis is found to be appropriate, it can be determined how many and in which factors the variable should be combined.
Food preparation ability
Food preparation ability is measured within 5 different items that are expected to result in one factor.
The exploratory factor analysis reveals that factor analysis is appropriate with a KMO value of .755 (KMO > 0.5) and a significant Bartelett’s test of sphericity (p=. 000). All communalities are larger than 0.4 and the value of Cronbach’s alpha, 0,876, certified a good internal consistency. Therefore the items meet the criteria to be combined into one strong factor.
5. Results
The fifth chapter presents the results of the analyses conducted. Firstly, it will be provided a general description of the survey, its respondents and the data collected. Subsequently, the data resulting by the 4 different linear regression analysis, one for each hypotheses, will be discussed. Finally, the hypotheses validation will resume which of the hypotheses formulated in the third chapter are supported and which are rejected.
5.1 Descriptive statistics
A total of 140 participants were initially recruited for this experiment, divided in two groups, the Eetmaatje group and the control group. 74 of these participants handed back their questionnaires and food waste diaries but only 38 of them filled them correctly. 20 of these 38 participants belong to the Eetmaatje group while the remaining 18 represent the control group.
The socio demographics characteristics of the 38 respondents are listed in table 2 below.
Gender Male 8
Female 30
Tot. 38
Age ≤ 30 1
30 < n ≤50 12
> 50 18
Didn’t fill the age 7
Tot. 38 53.4 years old
Monthly Household income Below 500 € 0 500 € - 999 € 0 1000 € - 1499 € 3 1500 € - 1999 € 2 2000 € - 2999 € 4 3000 € - 3999 € 9 4000 € or more 12 Didn’t fill the
income
8
Tot. 38 2800 €
Household size 1 2
2 18
3 9
4 7
5 0
Didn’t fill the household size
2
Tot. 38 2.58
Food waste Pasta and rice
With Eetmaatje 34.5 g
Without Eetmaatje 56 g
Food waste other categories
With Eetmaatje 564.47 g
Without Eetmaatje 1139.11 g
Food preparation ability 4.94
Table 2: sample descriptive statistics
The sample consists of 8 males (21%) and 30 females (79%). The majority of the respondents who filled the age is higher than 30 years old (78%). The average monthly income lies around 2800€
while the average household size is 2,58.
Before starting to test the hypothesis I adjusted the data obtained from the Food waste diaries in different categories. Firstly I divided the food waste data in two main categories: food and beverage waste. These two categories have different unit of measurement (g and ml). Subsequently I divided the food waste data in Pasta and rice, involved in the hypotheses 1 and 3, and other categories of food, involved in hypotheses 2 and 3. In other categories of food I decided to include also the beverage waste (liquid waste), using a 1 to 1 ratio to convert ml in g as used by the most regarding unit of measurement of food items.
Subsequently, to decide which control variables include in the linear regression, all the control variables are regressed on the dependent variable Food waste, including all the categories of food.
The regression analysis model yields a significance =.212 and with the threshold of significance fixed at < 0.05 this means that the control variables are not significant for explaining the dependent variable Food waste. In this analysis all the variables showing no significance even at the p level.
The complete results regarding the all the effects of the variables on the food waste are listed in the following Table:
Coefficientsa
Model Unstandardized Coefficients Standardized
Coefficients
t Sig.
B Std. Error Beta
1 (Constant) 2851,827 2213,201 1,289 ,212
age -14,861 20,714 -,174 -,717 ,481
household 74,527 366,618 ,053 ,203 ,841
income -38,480 213,077 -,041 -,181 ,859
gender -719,357 538,586 -,283 -1,336 ,197
a. Dependent Variable: total food waste (liquid and solid) Table 3: Regression Analysis control variables
5.2 Hypotheses testing
Two ANOVA and two regression analyses are then performed to assess whether there is a significant direct relationship between the use of the Eetmaaje, participants’ food preparation ability and the quantity of food wasted. The regression analysis is represented as follows:
𝑄𝐹𝑊 = 𝛼 + 𝛽 𝐸𝑇 + γ PA + δ ETPA + 𝜀 𝑊ℎ𝑒𝑟𝑒:
𝑄𝐹𝑊 = 𝑄𝑢𝑎𝑛𝑡𝑖𝑡𝑦 𝑜𝑓 𝑓𝑜𝑜𝑑 𝑤𝑎𝑠𝑡𝑒𝑑
𝐸𝑇 = 𝑃𝑟𝑒𝑠𝑒𝑛𝑐𝑒 𝑜𝑓 𝐸𝑒𝑡𝑚𝑎𝑡𝑗𝑒 0 = 𝑎𝑏𝑠𝑒𝑛𝑡 , 1 = 𝑝𝑟𝑒𝑠𝑒𝑛𝑡 PA= Preparation ability
ETPA = Eetmaatje x preparation ability 𝜀 = 𝑒𝑟𝑟𝑜𝑟 𝑡𝑒𝑟𝑚
As reported in the table below, an ANOVA analysis has been performed to test the first hypothesis, the main effect of the Eetmaatje on food waste, in this case Pasta and rice waste. However the results obtained are unfortunately not significant. In fact, as can be seen in the table below, the difference of the variance between the two groups can’t be explained by the presence of the Eetmaatje. There is a
significance of 0,492 when the threshold of significance required is 0.05. This is probably due to the low amount of data about pasta and rice waste available. Thus means that the first hypothesis is not supported.
ANOVA Sum of
Squares
df Mean Square F Sig.
Between Groups 4424,591 1 4424,591 ,483 ,492
Within Groups 330122,778 36 9170,077
Total 334547,368 37
Table 4: ANOVA Analysis Eetmaatje and pasta and rice waste
However, if we look at the graph below, we can notice that people who received the measuring cup, on average, wasted less compared to who didn’t receive it.
Figure 1: comparison between the average quantity wasted in pasta and rice categories
Subsequently, in order to test the second hypothesis, another ANOVA analysis has been performed to analyse if the Eetmaatje has a significant effect on the other categories of food wasted. How is possible to see in the table below, even if is very close to the threshold of significance, the Eetmaatje doesn’t have a significant role in explaining the variance between the Eetmaatje and control group (0,108 > p 0,05). Consequently the second hypothesis of the model is not supported.
34,5
56
0 10 20 30 40 50 60
Mean pasta and rice waste
With Eetmaatje Without Eetmaatje g
g
ANOVA
Sum of Squares
df Mean Square F Sig.
Between Groups 3128273,623 1 3128273,623 2,715 ,108
Within Groups 41482181,515 36 1152282,820
Total 44610455,138 37
Table 5: ANOVA Analysis Eetmaatje and other categories of food waste
How it is showed in the table and graph below, there is a wide difference between the average amounts of food wasted by the two groups.
Figure 2: comparison between the average quantity wasted in the other categories of food
Consumers who received the measuring cup have wasted on average 564,47 grams of food in one week, including liquids and excluding pasta and rice. Instead, those who didn’t receive it wasted almost the double, 1139,11 grams. However, the Eetmaatje cannot be considered as a significant factor to explain this difference.
Before starting with the analysis of the third hypothesis, I tested the food preparation ability of the participants involved in the study analysing and codifying consumers’ answers to 5 questions about food preparation ability skills. They were included in question 19 of the questionnaire. All the
564,47
1139,11
0 200 400 600 800 1000 1200
Mean other categories waste
With Eetmaatje Without Eetmaatje g
g
questions ranged from 1 to 7 and consequently also the food preparation ability of participants involved ranged from 1 to 7. The average food preparation ability of the sample is 4.94.
Subsequently, in order to test if the food preparation ability of the consumers involved has a moderating effect on the effectiveness of the intervention, hypothesis 3a and 3b, two regressions analysis have been performed. The variables involved in the first regression are pasta and rice waste, the variable created to test the interaction effect of food preparation ability (food preparation ability x Eetmaatje) and also the variable Eetmaatje presence. How is possible to see in the tables below, the model is significant (0,019 < 0,05) but the effect of food preparation ability on pasta and rice waste is not significant (0,969 > 0,05).
Model Unstandardized
Coefficients
Standardized Coefficients
t Sig.
B Std.
Error
Beta
(Constant) 56,111 22,891 2,451 ,019
interaction_effect -,893 22,942 -,030 -,039 ,969
Eetmaatje -16,075 145,696 -,086 -,110 ,913
a. Dependent Variable: PastaRiceWaste
Table 6: Regression Analysis pasta and rice waste with food preparation ability
With regard to the possible influence of consumers’ food preparation ability and attitude on the effectiveness of the intervention, the data resulted from the analysis doesn’t support the belief that consumers with different food preparation ability could be differently affected from the intervention.
The same process has been applied to test the hypothesis 3b, which wants to investigate if there is a moderating effect of the food preparation ability on the amount of food wasted in the other categories of food involved in the experiment, so excluding pasta and rice.
The table below shows that the model lie below the threshold of significance (0,00 < 0,05) but the interaction effect is still not significant (0,741 > 0,05). Also in these categories of food, level of consumers’ food preparation ability doesn’t have any significant effect on the amount of food wasted, and so on the effectiveness of the intervention.
Consequently, the hypothesis 3a and 3b are not supported.
Model Unstandardized Coefficients
Standardized Coefficients
t Sig.
B Std. Error Beta
(Constant) 1139,111 256,197 4,446 ,000
interaction_effect 85,497 256,768 ,250 ,333 ,741
Eetmaatje -1104,715 1630,660 -,509 -,677 ,503
a. Dependent Variable: Other categories waste
Table 7: Regression Analysis other categories of food with food preparation ability
Also here there isn’t any significant correlation between quantity of food wasted in other categories, presence of the Eetmaatje and food preparation ability of the participants. The quantity wasted is extremely heterogeneous and doesn’t have any relationship with the level of food preparation ability.
5.3 Hypotheses Validation
Hypothesis results
H1: The introduction of the Eetmaatje will reduce food waste in pasta and rice categories
Not supported
H2 : The introduction of the Eetmaatje will also influence food waste in other categories of food
Not supported
H3(a): The effectiveness of the Eetmaatje in food waste in rice and pasta categories will be higher for consumers with low food
preparation ability
Not supported
H3(b): The Eetmaatje’s influence in food waste in other categories of food will be higher with people for low food
preparation ability
Not supported
Table 8: hypotheses validation
6. Discussion
As already discussed in the beginning of this study, the increasing amount of food wasted and its environmental and economical serious consequences have increase the public awareness and create multiple questions regarding the reasons of food waste and the possibilities to solve this critical problem. Since food waste has so many important bad sides it is important try to extend the literature about this phenomenon that is still quite scarce up this date.
This study used a field experiment, entailing a questionnaire and a food waste diary, in order to explore to what extent an intervention in food preparation stage, specifically in portioning stage, can reduce the amount of household food waste. Moreover, it additionally analysed if the level of consumers’ food preparation ability actually have an influence on the effectiveness of the intervention, in terms of amount of food wasted. The study tried to shed light on the question, if interventions in this stage are effective tools to fight the critical issue of household food waste.
While there is an overall positive influence of the measuring cup on the amount of food and beverages wasted, on average people who received the Eetmaatje wasted less, it could not be proven as conceptualized. On the basis of the conceptual model four hypotheses were established and how is possible to see in table 5 of the previous chapter none of them could be supported.
In the next section I will try to understand and explain the reasons of these particular results obtained.
With regard of the categories involved in the first hypotheses of this study, pasta and rice, I will try to understand why there isn’t any significant relation between the introduction of the Eetmaatje and the quantity of pasta and rice wasted.
This result is surprising for different reasons. Considering that the measuring cup was projected to help consumers with pasta and rice portions the absence of any significant difference between the two groups involved in the study sounds quite strange.
A possible explanation lies in the fact that only 11 of 38 consumers wasted pasta or rice and of those eleven only five stated that they used the Eetmaatje.
According to what stated by Peers in 1996, sample size is one of the four inter-related features of a study design that can influence the detection of significant differences, relationships or interactions.
This can explain why the model purposed to test this hypothesis wasn’t significant. Eleven people cannot be considered a significant sample and this influenced in deep the results obtained
Another possible explanation can be found in the fact that according with the research conducted by the Dutch nutrition foundation in 2014, pasta and rice account only for the 0,07% of the total amount of food wasted during one person’s lifetime. This can explain the low amount of data collected about pasta and rice waste in only one week. Consequently, seven days cannot be considered a reliable period of time to test the amount of waste in those two categories that, even if are becoming every year more common in the Dutch diets, are still not predominant in the Dutch culture of food.
Another motives can lie in the fact that some participants didn’t even use the measuring cup.
This can depends by the fact that the average food preparation ability of the participants was quite high (4,94 of 7) and so people didn’t perceive the measuring cup as a helpful object because they probably thought their food portioning skills were enough adequate. (Rolls, Morris and Roe; 2002) Different conclusions can be drawn regarding the second hypothesis of the model. It aimed to investigate the possible cross-category effects that the introduction of the measuring cup could cause.
Here the difference between the Eetmaatje and the control groups in terms of food wasted in the other categories of food was quite wide but couldn’t be entirely explained by the presence of the Eetmaatje.
So, even if the hypothesis is not statistically supported, it seems clear that the introduction of an object like the Eetmaatje can affect consumers’ waste not only in the categories directly involved in the usage but also in the other categories of food involved in the consumption. This is probably due to the fact that people who received the measuring cup felt more involved in the food waste issue and as a consequence wasted less (Morris et al; 2012).
Further, with regard to the possible influence of consumers’ food preparation ability on the effectiveness of the intervention, the data resulted from the analysis doesn’t support the belief that consumers with different food preparation ability could be differently affected from the intervention.
This is probably caused by the fact that the data sample is not representative. Only 38 consumers are not enough to test the influence of consumers’ food preparation ability, because of the extreme heterogeneity of the data collected that didn’t permit to find significant differences. So, the size of the data available has deeply influenced the significance of the result collected (Peers 1996).
The only interesting insight highlighted from the data collected in this part of the study, is that people with higher food preparation ability tend to waste less pasta and rice. But the difference is too small to be considered significant.
Furthermore, another possible explanation for the not significant results obtained is that the experiment could be perceived as too intrusive. In fact, half of the participants initially recruited didn’t hand back the questionnaire and food waste diary received. This study required a daily effort for an entire week and this fact have probably influenced participants’ willingness to finish the experiment.
6.1 Managerial implications
In general, the most important conclusion for practitioners derived from this particular research is the finding that overall consumers who received the measuring cup wasted less. Unfortunately, this difference can’t be entirely explained by the introduction of the measuring cup. However this paper can be a signal that more interventions in food portioning stage are needed because, especially in the Netherlands, is necessary invert the alarming trend of over size portions.
A possible step toward future interventions could entail increasing advertising by public policy makers in order to provide general information regarding the problematic of food waste. These advertisements could present use of measuring cups among other things as a solution for households to reduce their amount of waste.
Moreover, advertising by companies and retailers producing and selling products with different portion sizes would allow making consumers aware of the large portions range and choice possibilities within the food category, giving them the possibility to buy the exact right amount of food they need.
Moreover, retailer promotions on these items would increase the awareness while grocery shopping and could enlarge the purchase probability, thus even increase the profit of retailers.
6.2 Limitations and further research
This study is subject to many limitations, which have to be assessed, as these restrictions have to be accounted while interpreting the results. However, some of these limitations also translate into opportunities for further research.
First of all the representativeness of the sample needs to be discussed. The size of the data set of 38 participants is very limited and cannot be seen as representative for the entire population, in this case Dutch households. Regarding the age of the sample, no participant is below 25 and the age group of 50 or more years is overrepresented. Moreover, the study entails much more female than male participants (79% vs. 21%). Finally, the study participants are quite wealthy as 55% of the study sample earns between 3000€ and 3999 € or even more than 4000€. In order to be able to confirm the
