Development and Standardization of Tools Regarding Junk Food Consumption
- 1 Abstract
- 2 Introduction
- 3 Tools construction
- 4 Demographic information
- 5 Physical health
- 5.1 Dimensions: Identifying the junk food
- 5.2 Knowledge of nutrition: Balance diet
- 5.3 Junk food and health problems
- 5.4 Validation of Knowledge scale
- 5.5 Readability validation
- 5.6 Test (pre-tryout) of knowledge scale
- 5.7 Calculation of discrimination index of Knowledge scale
- 5.8 Reliability of the knowledge scale – Test-Retest method
- 6 Validation of Attitude scale
- 7 References:
In present days the junk food has become ubiquitous in the world food markets. Eating frequent junk foods is causing obesity and related diseases among children, adolescents, young adults and adults as well. Promotion of healthy lifestyle is required to reduce health risks in young age and adulthood. Healthy lifestyles and food habit require correct knowledge, attitude, practice and motivation. The present paper aims to discuss on the construction and validation of survey tools for measuring knowledge, attitude, practices regarding junk food consumption and its impact on health of people of West Bengal. Questionnaires were constructed as data collection tool. The questionnaire was prepared on the basis of certain dimensions. Initially the questionnaire was administered on 30 subjects representing the target population. After a pre-test among 30 respondents the readability, discrimination indices, and difficulty indices were determined for ‘Knowledge’ questionnaire, discriminating indices and Chronbach’s alpha parameter were used for ‘Attitude’ questionnaire and ease of readability for ‘Practice’ and ‘Health effect’ questionnaire were conducted. Rejection criteria were set for each parameter and the final questionnaire was constructed with the items retained after validation. Initially Knowledge questionnaire had 41 items and finally it retained 37 items. Similarly in the Attitude scale, among 27 test items 5 were rejected after validation. But in 37 items all the test items retained. Finally the reliability of the tool was confirmed by Test-Retest method.
Worldwide food selection and consumption pattern have been increased a lot towards readymade foods within a couple of decades. Exercise of brain has increased but normal physical exercise has got reduced. The consequences of these two have increased various health risks in our children, young adults and adults, like reduction in stamina, obesity, juvenile diabetes, high blood pressure, etc. Their educational level also may have effects in this regard. Eating frequent junk foods causes teens and young adults to gain more weight and they face an increased risk of developing obesity. Childhood obesity has more than tripled in the last three decades. The occurrence of obesity among adolescents has increased from 5 to 18% (Mandal and Mandal, 2012). As per National Institute of Nutrition (NIN) “junk foods” are defined as “those containing little or no proteins, vitamins or minerals but are rich in salt, sugar, fats and are high in energy (calories)”. Artificially aerated drinks, ice creams, potato chips, chocolate, French cries are some examples of Junk food (Krishnaswamy & Sesikeran, 2011). A study by Sharma (Sharma, 2013) suggested that junk food consumption alters brain activity in a manner similar to addictive drugs like cocaine or heroin. After many weeks with unlimited access to junk food, the pleasure centers become decentralized, requiring more food for pleasure. Junk food consumption is giving rise to obesity health problems, like, diabetes, juvenile diabetes, cardio-vascular diseases, gastro-intestinal problems etc. among the people.
Dietary behaviour is important for the development and growth of human beings. Ideally a person should have healthy food habit with minimum or no consumption of junk food. The person should have knowledge regarding nutrition and junk food, proper attitude to avoid junk food consumption. But in reality, People of West Bengal are consuming more and more junk food and lesser healthy foods. They are becoming addicted to junk food.
A descriptive study will be conducted in West Bengal which will provide us with a snapshot of the present situation in terms of knowledge and attitude towards junk food, junk food practices of our present and future citizens of West Bengal and their present health (physical and mental) status. The subjects will belong to The results of the study may help our families to select better food and consumption behavior, make us aware and sensitize us against the junk foods. Development and standardization of research tools is the essential step for any research study to be conducted systematically. In the present study the details regarding the construction of the tools needed for the survey research and their validation is described. The main objectives of this study are (i) to construct knowledge questionnaire for measuring the knowledge score regarding junk food consumption, (ii) to construct attitude questionnaire for measuring the attitude score towards junk food consumption, (iii) to construct practice questionnaire for practice score related to junk food consumption and (iv) To construct knowledge questionnaire for measuring the knowledge score regarding junk food consumption.
Though there are many types of survey tools at present, researchers generally use the interviews and questionnaire for data collection (Creswell, 2012). In the present study, questionnaire was selected and designed for collection of data. A study of junk food consumption of adolescents and adults were conducted with the following questionnaire (or tool) to assess their knowledge regarding junk food (K), attitude towards junk food consumption (A), consumption practice of junk food (P) and health effects of junk food on the subjects (H).
The options of each item were arranged in such a way that if the score increases it will contribute to the increase in the overall score of K-score, A-score, P-score and H-score. The significance of increase or decrease of each score (like K, A, P, H) is depicted under each questionnaire. The questionnaire has the following five parts:
Part-I : Demographic information of the people
Part-II : Questionnaire on Knowledge about junk food (K-score)
Part-III : Questionnaire on Attitude towards Junk Foods (A-Score)
Part-IV : Questionnaire for Practice Related to Junk Food (P-Score)
Part-V : Impact of Junk Food Consumption on Health (H-Score)
In the present study the characteristics of subjects collected were – name, address (viz. village and urban), age group including the adolescent group (age group (15 to 21 years), young adults (22 to 35 years) and mid adulthood (above 35 years), gender (male and female), educational qualification [(i) primary, (ii) secondary, (iii) higher secondary and (iv) higher education)], occupation, physical structure [Body mass Index (BMI) and Waist circumference to height ratio (WCH)]
To gauge the physical health status, especially the degree of obesity, BMI (body mass index) is widely used by medical practitioners. It is expressed as the ratio of body mass (kg) and square of height (sq. m.). According to BMI, persons are categorized into (i) underweight (ii) normal weight (iii) overweight and (iv) obese.
Waist-circumference (WC) is reported as a good indicator of abdominal fat around the waist. According to US National Institute of Health (NIH) (“Obesity Education Initiative Electronic Textbook–Treatment Guidelines,” 2018) waist circumference (WC) exceeding 102 cm (40in) for men and 88 cm(35in) for (non-pregnant) women, is considered high risk for type 2 diabetes, dyslipidemia, hypertension and cardio vascular diseases (CVD). WC is considered as a good indicator of obesity-related disease risk than that of BMI. Since, in this work, younger persons were included in the survey, instead of WC another related indicator – waist circumference to height ratio (WCH) was considered. Increased waist circumference can also be a marker for increased risk even in persons of normal weight. (“Obesity Education Initiative Electronic Textbook–Treatment Guidelines,” 2018)
Construction of Knowledge questionnaire to measure knowledge regarding Junk food consumption (K-score)
Knowledge is the understanding of any given topic (Kaliyaperumal, 2004). The K-score of a subject is expected to increase with the knowledge of junk food and his/her distinguishing power between nutritious food and junk food. It is expected that if a subject has greater K-score then he/she will show less tendency of consuming junk food. The dimensions like identifying the junk food, knowledge of nutrition, junk food and health problems were taken for the knowledge scale.
Dimensions: Identifying the junk food
The questionnaires were formulated by keeping in mind that the participants would have to ponder over each option and in no case the answer was directly embedded in the question itself. The item numbered K.1 contained 16 foods and the question was to categorize them under two food categories (i) Healthy food and (ii) Junk food. Multiple options were correct. “Yes/No” – type of options were avoided. Open ended question could have fetched more accurate result of knowledge of a subject regarding junk food, but it would have been more difficult to quantitate.
Knowledge of nutrition: The physiological function of food groups
In this section four items K.2, K.3, K.4 and K.5 were enlisted. In question K.2 two options were correct. If a subject was able to identify both the options the points secured would be 02. Multiple correct options made the choice making slightly difficult for a subject. It inserts a certain degree of uncertainty. Thus it was expected to produce greater degree of discrimination from this type of questions. The rest of the questions ranging from K.3 to K.5, all had single correct option.
Knowledge of nutrition: The comparison of foods in terms of specific nutrient content
Each subject should know that which food item contains which nutrients like fat, carbohydrate, protein, vitamins and minerals. K.6 and K.7 contain a single correct option each. K.8 item comprises of three options (i) Yes, (ii) No and (iii)I don’t know. The correct option was ‘Yes’. When a subject selected the option ‘Yes’ the score taken was one, otherwise both the incorrect option fetched zero.
Knowledge of nutrition: Balance diet
Two questions K.9 and K.10 were created to check the knowledge of balanced diet. In K.9 three options of servings were given.
Junk food and health problems
A subject should know the problems associated with junk food consumption. This was included in the domain of knowledge. Seven items ranging from K.11 to K.17 were given, out of which K.11 itself contained 7 correct options and hence the highest possible score of seven. K.13 had three correct options with a maximum possible score of three and rest of the items had single correct option each.
Validation of Knowledge scale
Evaluation of adequacy and appropriateness of the interpretations and uses of assessment results is the validity (Linn & Mlller, 2005).
The language of the questions may not be understandable by the respondents. Since several technical terms were used in constructing the questionnaires and persons were selected from different subject streams like science, arts or commerce, therefore the language and the words used in the questions should be understandable by the target persons. The Flesch-Kincaid readability test was employed to measure the difficulty level of a passage in English to understand it. MS Word® 2007 (Microsoft Inc.) was used for calculating Flesch Reading Ease and Flesch-Kincaid Grade Level (Flesch, 1979).
The sentences of the questions were so structured that the Flesch-Kincaid Grade Level was aimed at 8 or lower. The meaning is, the language of the questions were understandable to persons with knowledge of 8th standard. The average of the total 16 questions was found to be 7.4 and the maximum and minimum “Flesch-Kincaid Grade Levels” were found to be 11.6 and 2.2 respectively. The range of “Flesch-Kincaid Grade Level” may be expressed as 7.4 ± 2.8 (SD). Therefore, the language was easy to read and it may be taken as Plain English. Easily understood by 13- to 15-year-old students.
Test (pre-tryout) of knowledge scale
A total of 30 respondents were chosen among friends, family and acquaintances to get a wide range in age, sex, socio economic status, educational background and covering different parts of West Bengal in the test?population. The items were prepared in two languages, Bengali and English. The questionnaire was sent to the respondents in written form. Respondents were asked to fill out the questionnaire in relaxed pace. They were asked to note the start time and the end time to obtain the time required for answering the questionnaire. After completion the respondents were asked to note their experience of answering the questionnaire with the help of five options (i) Very easy (ii) Easy (iii) Normal (iv) Difficult (v) Very difficult. From the pie-chart (Fig. 1) it is evident that majority of the respondents found the questionnaire not difficult at all.
Figure1. Experience of answering the questionnaire by the respondents
Determination of difficulty index of each item of Knowledge questionnaire
The difficulty index of an item is defined as the proportion of respondents giving correct answer to that particular item. The difficulty index of the knowledge questionnaire was calculated and the items having difficulty indices within 20 to 80% were retained in the final questionnaire, rest of the items were rejected.
Calculation of discrimination index of Knowledge scale
Discrimination index is a parameter that shows the sensitivity of the knowledge tool. The respondents were grouped into upper and lower-scoring groups of equal size. First the total score of each candidate was calculated by summing the scores of each item and then the rows were sorted by the total score. The respondents were divided into two groups of upper 27% of the candidates (i.e. 8 nos,) and the lower 27% (i.e. 8 nos.). The proportion of the respondents responding correctly pertaining to a particular item in the lower scoring group (PL) is subtracted from the proportion of the candidates responding correctly in the upper-scoring group (PU). Finally the discrimination index was calculated by the following formula:
D = PU – PL Eqn. 1
The guideline for interpretation of D-values prescribed by (Ebel, 1967) was adopted to reject or accept an item. Items with large D-values signified large differences in the proportion of correct responses between two groups. Larger D values are suitable for inclusion in the final tool while items with smaller or negative D-values were not.
Reliability of the knowledge scale – Test-Retest method
The total score of a respondent was summed up and the score was normalized by calculating the percentage with respect to the highest possible score, i.e. 41 for the knowledge tool. Same questionnaire was given to a respondent twice but after an interval to assess whether a respondent gives the same answer again. The time gap between the test (T1) and retest (T2) was 30 days. Correlation coefficient was calculated from the paired scores of the respondents (i.e. T1 and T2). Correlation between T1 and T2 scores was found to be R= 0.76090.
Figure 2 Reliability of K-score (R = 0.76090)
Construction of Attitude questionnaire to measure attitude towards junk foods (The A-score)
Attitudes are emotional, motivational, perceptive and cognitive beliefs that positively or negatively influence the behaviour or practice of an individual (Andrien, 1994; de Landsheere, 1983)]. Attitudes influence the behaviour of an individual towards a subject rather than his/her knowledge on it. Here five point Likert scale was used for its ease of application over a wide range of respondents and requirement of lesser time for validation compared to Thurstone scale. In this scale a series of statements related to people’s attitude towards a certain dimension is followed by five options of increasing agreement to the statement.
The A-score of a respondent is expected to increase if he/she has positive attitude towards avoiding junk food. It is expected that if a respondent has greater A-score then he/she will show less tendency of consuming junk food in practice. Questions were framed with the following dimensions: (i) Education, (ii) Parental attitude, (iii) Prohibition, (iv) Subjective belief, (v) Food preference, (vi) Perceived behavioral control and (vii) Perceived health problems. Total 27 questions were constructed in this section each having 5 point Likert scale with five options (i) Strongly agreed (ii) Partially agreed, (iii) Neutral, (iv) Partially disagreed and (v) Strongly disagreed. Highest score may be five. The Items which were depicting positive opinion would score 5 to 1 and the negative opinion scored 1 to 5.
Validation of Attitude scale
The average “Flesch-Kincaid Grade Levels” of the total 27 questions was found to be 5.0 with maximum and minimum of 11.7 and 0.0 respectively. The range of “Flesch-Kincaid Grade Level” may be expressed as 5.0 ± 3.0 (SD). Therefore, the language was very easy to read and may be easily understood by an average 11-year-old student.
Discrimination index of Attitude scale
Discrimination indices of all the items in Attitude questionnaire were calculated according to the procedure described in ‘Calculation of discrimination index of Knowledge scale’ (vide section 3.6.2). The discrimination index of an item of Attitude scale was determined by the following formula:
D = PU – PL Eqn. 4.2
The guideline for interpretation of D-values prescribed by (Ebel, 1967) was taken as the guideline to reject or accept an item.
Internal consistency of items by Chronbach’s alpha method
To validate an Attitude scale the internal consistency of an item was determined by Crohbach’s alpha parameter. Cronbach’s alpha parameter was calculated from SPSS Ver. 20. Items having Chronbach’s alpha value greater than 0.70 were accepted of having internal consistency and below it were rejected. Finally 6 items were rejected. The final attitude scale had total 21 items.
Reliability of the Attitude scale – Test-Retest method
After one month of the Test (pre-tryout) the same questionnaire was supplied to the same group of the participants and the data were collected. Correlation coefficient was calculated from the paired scores of the respondents (i.e. T1 and T2). The value of the correlation coefficient was found to be (R) 0.7653. Thus the tool had high reliability.
Figure 3 Reliability of A-score (R = 0.7653)
Construction of Practice questionnaire to measure practice related to junk food consumption (P-Score)
The P-score of a subject is expected to increase if he/she consumes greater amount of junk food. The question items were directed towards getting the frequency of consuming junk food, doing exercise or not and related habits.
Dimension: Junk food eating habit
The consumption habit of a subject was intended to be captured by a food frequency table. It contains five categories of junk foods in the first column, namely (i) Tea/coffee, (ii) carbonated drinks (like Pepsi, Coke, Thumsup, Sprite, etc.), (iii) Processed drinks (Slice, Mazza, etc.), (iv) Candy / icecream / cookies / cakes / chocolates / sweets, (v) Potato fries / chips / chanachur / popcorn / salty snack foods.
The consumption frequency was captured by six columns having the following headings (i) More than once per day, (ii) Every day, (iii) 2-3 times per week, (iv) Once in a week, (v) Seldom (not often), (vi) Never. The highest score was allotted to choice (i) S = 5 and was decreased towards choice (vi) S = 0.
Six more items were placed under Practice questionnaire – P.2 to P.7 under, miscellaneous dimensions like (i) Exercise and (ii) Other behaviors.
Validation of Practice questionnaire
A subject who has more knowledge about junk food is expected to consume lesser amount of junk food and vice versa. It included the dimensions like, junk food eating habits, exercise and other behavior.
The average “Flesch-Kincaid Grade Levels” of the total 07 questions was found to be 5.0 with maximum and minimum of 6.8 and 0.0 respectively. The range of “Flesch-Kincaid Grade Level” may be expressed as 5.1 ± 2.4 (SD). Therefore, the language was very easy to read and may be easily understood by an average 5th-grade student.
Reliability was determined from test-retest by correlation coefficient which was calculated from the paired scores of the respondents (i.e. T1 and T2). The value of the correlation coefficient was found to be (R) 0.7902.
Figure 4 Reliability of P-score (R = 0.7902)
Construction of questionnaire to assess the Health Impact of junk food consumption (H-score)
The H-score of a subject is expected to increase if he/she suffers from health problem due to junk food consumption. Under this section questionnaires were set under two dimensions (i) Addiction to junk food and (ii) Health condition. The scores under each option were set keeping in mind the objective of – “the higher the health score poorer the health of the subject”.
Dimension: Addiction to junk foods
Two questions (H.1 and H.2) were set to assess whether the subject has addictive urge towards junk foods or not.
Dimension: Health Condition
Question item H.3 contained five junk food related diseases. The subject had to select any one or more diseases with which he/she was suffering. Each disease carried one H-score each. As the number of ticks increased the total H-score was summed up accordingly. A sixth option was given having H-score equal to zero, i.e. “Other (Pl. state ____ )”. This option was intended to identify any other diseases that may be linked to junk food consumption.
Two health parameters, (i) Body Mass Index (BMI) and (ii) Waist to Height ratio (WHR) – these two meta data were calculated from three raw data of a subject – (i) Height, (ii) Weight and (iii) Waist circumference. Whatever units the respondents input, the height was converted to meter, weight to kilogram and waist circumference to inches.
Validation of questionnaire to measure the Impact of Junk Food Consumption on Health
2.8 was found the average of “Flesch-Kincaid Grade Levels” of total 04 questions with maximum and minimum of 5.8 and 1.2 respectively. The range of “Flesch-Kincaid Grade Level” may be expressed as 5.0 ± 3.0 (SD). Therefore, the language was very easy to read and may be easily understood by an average 3rd-grade student.
The value of the correlation coefficient was found to be (R) 0.79678 which was calculated from the paired scores of the respondents (i.e. T1 and T2). The value of the correlation coefficient was found to be (R) 0.79678.Thus the Reliability of the questionnaire was determined.
Figure 5 Reliability of H-score (R = 0.79678)
In the present study questionnaire tools were constructed which were related to junk food consumption among the people of West Bengal. The questionnaire consisted of five parts, viz. the demographic information, the knowledge regarding junk food consumption, attitude towards junk food, junk food consumption practices, and impact of junk food consumption on health. Each part of the questionnaire was constructed based on some dimensions. Pre-tryout was conducted among 30 respondents. The respondents included different age groups, educational status, gender and location as required for the research. Validation of the knowledge questionnaire having 41 items was done by the Flesch- Kincaid readability test, difficulty index, discrimination index and finally 37 retained. In case of attitude part of the questionnaire internal consistency was determined by Cronbach’s alpha parameter along with discrimination indices for 27 items. In the final questionnaire 21 items were retained depending on the rejection criterion. In practice and health questionnaire only Klein- Flesch- Kincaid readability test was conducted and all the items were retained. Test-retest method was employed followed by calculation of correlation coefficient between the paired test scores and the reliability of questionnaire was found high in all the questionnaires.
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