Development of a General Nutrition Knowledge Questionnaire for Adults

Development of a general nutrition knowledge questionnaire for adults

K Parmenter1 and J Wardle1*

1ICRF Health Behaviour Unit, University College London

Objective: This paper describes the development of a reliable and valid questionnaire to provide a comprehensive measure of the nutritional knowledge of UK adults. The instrument will help to identify areas of weakness in people's understanding of healthy eating and will also provide useful data for examining the relationship between nutrition knowledge and dietary behaviour which, up until now, has been far from clear. Design: Items were generated paying particular attention to content validity. The initial version of the questionnaire was piloted and assessed on psychometric criteria. Items which did not reach acceptable validity were excluded, and the ®nal 50 item version was administered to two groups differing in nutritional expertise on two occasions to assess the construct validity and test-retest reliability. Setting: The questionnaire was developed in 1994 in the UK. Subjects: Three hundred and ninety-one members of the general public, recruited via their places of work, completed the questionnaire at the piloting stage. The ®nal version was administered to 168 dietetics and computer science students following a university lecture. Results: The internal consistency of each section was high (Cronbach's alpha 0.70 ± 0.97) and the test-retest reliability was also well above the minimum requirement of 0.7. Nutrition experts scored signi®cantly better than computer experts [F(1167) 200.5, P < 0.001], suggesting good construct validity. Conclusions: The ®ndings demonstrate that the instrument meets psychometric criteria for reliability and construct validity. It should provide a useful scale with which to reassess the relationship between knowledge and dietary behaviour. Sponsorship: The study was funded by a grant from the Biotechnology and Biological Sciences Research Council. Descriptors: nutrition knowledge; psychometrics; diet; questionnaire

Introduction and recipes to help people make the recommended dietary changes. Since the 1950s the link between diet and chronic diseases Despite the intuitive appeal of education as a means of such as cancer and cardiovascular disorders has been improving diet, many studies in this area have failed to ®nd increasingly well recognised world-wide (WHO, 1990). signi®cant associations between nutritional knowledge and In the UK, attempts to improve the nation's health through dietary behaviour (Axelson et al, 1985). If these conclu- dietary change have tended to centre around education. sions are correct and knowledge really has little or no Underlying this approach is the assumption that providing impact on dietary behaviour, then the implications for people with the information necessary to choose healthy campaigns to improve people's diet are important. It foods will ultimately lead to an improvement in diet. could be that resources used for public education pro- According to this view, given accurate information about grammes are being wasted if knowledge does not, in fact, what they should be eating and the implications for their have a major in¯uence on behaviour. health if they eat the `wrong' foods, people will change One alternative explanation for the inconsistent associa- their diets appropriately. Organisations like the Health tions between knowledge and dietary behaviour, is that Education Authority in the UK produce extensive literature knowledge could be being poorly assessed. Psychometrics, aimed at informing people about appropriate dietary beha- the science of measuring or scaling psychological attri- viour. Their most recent lea¯et, entitled `Eight Guidelines butes, has de®ned a set of criteria for a valid test (Kline, for a Healthy Diet' (HEA, 1997) includes advice to eat 1993). The items should sample the full domain of the more starchy foods, plenty of fruit and vegetables and to attribute in question and be phrased simply and unambigu- cut down on fatty and sugary foods, as well as information ously (content validity). Individual items should (usually) about what these foods are, explanations of the kinds of not be so easy that almost everyone completes them, nor so health bene®ts of following the guidelines and practical tips dif®cult that very few complete them. Individual items within a scale or subscale should be well correlated to the total subscale score (internal reliability). Scores should *Correspondence: Professor J Wardle, ICRF Health Behaviour Unit, remain stable when the test is completed twice over a Department of Epidemiology & Public Health, University College reasonable time period, that is long enough for precise London, 2 ± 16 Torrington Place, London WC1E 6BT. Received 7 July 1998; revised 14 October 1998; accepted 17 November answers to be forgotten, short enough to minimise real 1998 change in the measured attribute (test-retest reliability). General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 299 Table 1 Psychometric validation of existing nutrition knowledge questionnaires

Authors (year) Target population Scope Psychometric measures

Anderson et al (1988) Medical in-patients General nutrition knowledge Content validity Bergman et al (1992) Adult women Caffeine knowledge KR 0.6 for reliability McDougall (1998) Teenagers General nutrition knowledge Content validity Test-retest reliability Resnicow et al (1997) Adults Fat, ®bre & cholesterol Construct validity Sapp & Jensen (1997) Adults Diet and health knowledge Construct validity < 0.7 Shepherd & Towler (1992) Adults General nutrition knowledge Construct validity Sta¯eu et al (1996) Adults (Dutch) General nutrition knowledge Content validity Construct validity Test-retest reliability Steenhuis et al (1996) Adults (Dutch) Knowledge relating to fat Test-retest reliability r 0.85

Finally, when administered to samples known, on other surveys carried out between 1989 and 1991. Using exten- grounds, to vary on the attribute in question, for example, sive psychometric evaluation, the authors found that the by virtue of specialist training, the scores should be nutrition knowledge questionnaire did not meet standards signi®cantly different (construct validity). Apart from con- for reliability, highlighting the need for a more reliable tent validity, which is assessed qualitatively, all these are instrument. They did, however, ®nd that the questionnaire statistically measureable and there are standard cut-off used to test awareness of the relationship between diet and values for reliability and validity, beyond which items or health has acceptable reliability as well as good construct scales become unacceptable. validity. Nutrition questionnaires developed to date generally Further encouragement that it is possible to develop have limitations in one or more of these areas (see Table instruments which meet psychometric criteria comes from a 1 for a summary). Either they lack the kind of psychometric study in the Netherlands. Sta¯eu et al (1996) used an validation described above, or they cover only a limited adaptation of a questionnaire based on Dutch dietary area of nutrition knowledge. For example, Towler & guidelines. Reliability and validity were both found to be Shepherd's (1990) questionnaire is shown to have good high. Again, the scope of the questionnaire is narrowed, to construct validity and internal reliability, but the authors cover only fat and cholesterol, so it could not be used to say little about how the items were generated and the assess overall nutrition knowledge. As well as this, because content validity is therefore questionable. It is, for example, of cultural variations in eating habits and precise dietary hard to see how an item which asks about the hormones recommendations, an instrument developed in the Nether- involved in hunger would be related to dietary behaviour. lands would not necessarily be valid for a UK population. There are no questions about diet-disease links, and Although general recommendations are typically similar although knowledge about the nutrient content of foods is across different westernised countries, speci®c question- thoroughly tested, there is no systematic questioning about naires might need adapting to take account of cultural dietary recommendations. variations in diet. By contrast, Anderson et al (1988)) used a questionnaire Given the problems of measuring nutrition knowledge with good content validity and a sound rationale. Items and the ambiguity of the ®ndings to date, it is perhaps tested familiarity with nutrition terms, knowledge about premature to dismiss the link between knowledge and current dietary recommendations, and the practical applica- behaviour without ®rst trying to develop a reliable and tions of these recommendations. However, the instrument valid instrument with which to test a broad range of was not subjected to rigorous psychometric validation, so nutrition knowledge of adults. The aim of this study, nothing can be said about the construct validity or test- therefore, is to develop and validate such a questionnaire retest reliability, and the internal consistency is shown to be which can then be used to look again at the relationship poor. This is also true of McDougall's (1998) study, between nutritional knowledge and dietary behaviour. although her questionnaire has good content validity. How- ever, construct validity was not assessed and the test-retest Methods reliability was measured at an interval of only a day, so although it was found to be high, it is not possible to know Developing the questionnaire item pool whether the measure would be stable over a longer period On the basis of this review of current material containing of time. As the questionnaire is speci®cally designed for dietary advice and the literature linking diet with disease, it use with teenagers, it might not be suitable for use with an was decided to divide the questionnaire into ®ve main adult sample. sections: the understanding of terms (such as ®bre and Other studies have used reliable instruments on adult cholesterol); awareness of dietary recommendations (in samples, but have concentrated on a particular aspect of lea¯ets like the one described earlier); knowledge of food nutrition, for example, fat (Steenhuis et al, 1996) or fat, sources related to the advice, that is, which foods contain ®bre and cholesterol (Resnicow et al, 1997). These, which nutrients; using the information to make dietary although useful, would not, therefore, be appropriate for choices (practical food choice); and awareness of diet- use in measuring the overall nutrition knowledge of a disease associations. Using these broad categories, an population. item pool of 1201 was generated. Some items were taken A large-scale study in the USA (Sapp & Jensen, 1997) from existing questionnaires while others were generated assessed the reliability and validity of the nutrition knowl- from the literature with expert advice from dieticians where edge measures used in the Diet and Health Knowledge necessary. It is believed that this process served to General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 300 maximise the content validity of the questionnaire, that is, Analyses and results that the items selected were representative of the whole The results were analysed both quantitatively (for item area of knowledge being measured. dif®culty, item discrimination and internal consistency) and Using this pool of items, two reviews were carried out qualitatively (which involved looking at comments made by a panel of four psychologists and four dieticians to select by respondents). the best in terms of clarity of the questions, accuracy of the dietary knowledge being tapped, and interpretability. This process reduced the number of items to 102. The prelimin- Item dif®culty ary instrument was then ready for piloting in a general According to Kline (1993) items are not useful if they are population sample. answered correctly by more than 80% or fewer than 20% of A number of demographic questions were included in respondents. These indices were adjusted upwards slightly the survey to characterise respondents. A literature search as the pilot sample was skewed towards characteristics of existing questions was carried out and 12 items chosen which have previously been associated with higher than from a pool of 58. These asked about sex, age, marital average nutrition knowledge (Crawford & Baghurst, 1990; status, ethnic origin (categories taken from the UK 1991 Levy et al, 1993). Items were therefore rejected over 90% Census), number of children, children under 18 y living at or under 30% of respondents answered them correctly. Of home, educational level, nutrition-related quali®cations, the items which did not meet these criteria, about a quarter occupation and partner's occupation (classi®ed according were retained on the grounds of content validity, that is to the Standard Occupational Classi®cation system), they were considered to be testing an essential aspect of employment status and details of any special diets. nutrition knowledge not covered elsewhere in the questionnaire.

Item discrimination Subjects and method of distribution for the preliminary The ability of each individual item to discriminate between questionnaire people with different levels of knowledge was measured by Nine hundred questionnaires were distributed to a variety correlating the score on each item with the overall test of organisations for their employees with the request that score. An item-to-total-score correlation of 0.2 has been they complete and return them (in a pre-paid envelope) and cited as the cut-off point below which items should be add any comments that might occur to them. Hierarchical discarded (Kline, 1986; Streiner & Norman, 1992). This organisations were canvassed, in the hope of reaching was adhered to except in circumstances where an item was people from a range of socio-economic backgrounds. Of considered particularly important in terms of content valid- the 900 questionnaires, 43.3% were completed and ity. returned, although given that distribution was left to the recruited organisations, this is probably an underestimate of Internal consistency the actual response rate. The majority of respondents were This was measured separately for the different sections, women (72.1%), aged between 18 and 44 y (72.4%), white each of which was tapping a different area of knowledge. (95.4%) and had non-manual occupations (82.4%). The The minimum requirement for internal consistency has demographic characteristics are shown in Table 2. been recommended as 0.7 (Kline, 1993). It was calculated for each section as follows (using Cronbach's alpha): understanding of terms: 0.69; dietary recommendations: Table 2 Sample characteristics (n 391) 0.76; sources of nutrients: 0.8; choosing everyday foods: 0.66; diet-disease relationships: 0.79. n % Gender Respondents' comments Male 109 27.9 Some changes to wording were made in response to Female 282 72.1 Age comments written on the questionnaires, in order to Under 18 29 7.4 reduce ambiguity and maximise the clarity of the questions. 18 ± 24 92 23.5 On the basis of the analysis described above, the number 25 ± 34 116 29.7 of items was reduced to 50. The ®rst section (the under- 35 ± 44 75 19.2 standing of terms) was removed completely as so few items 45 ± 54 45 11.5 55 ± 64 18 4.6 met statistical criteria while others were judged to be too 65 ± 74 12 3.1 scienti®c and not relevant to behaviour. The ®nal survey 75 and over 4 1.0 was presented as a four page booklet. (Questions are shown Socio-economic status in Appendix 1. Copies of the questionnaire booklet are Non-manual 253 82.4 Manual 54 17.6 available from authors on request). Ethnic origin White 373 95.4 Other 18 4.6 Evaluation of validity and reliability of the ®nal scale Marital status Single 162 41.4 The next step was to test construct validity (Streiner & Married=cohabiting 198 50.7 Norman, 1992; Kline, 1993) of the ®nal version by admin- Divorced=widowed 31 7.9 istering it to two groups known to differ in their nutrition Employment status knowledge. Test-retest reliability had to be veri®ed to make Employed full time 189 48.3 sure that the results produced were consistent over time Employed part time 63 16.1 Other 139 35.6 (Streiner & Norman, 1992; Nunnally, 1978). Internal consistency was also reassessed for the ®nal version of the General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 301 questionnaire. Minimum requirements for test-retest relia- Construct validity bility and internal consistency were 0.7 (Kline, 1993). Table 4 shows that the dietetics students scored consistently higher than the computer science students on all sections of the questionnaire (P < 0.001). Subjects and methods Given the different gender balance of the two groups, Participants in this study were ®nal year undergraduate gender was controlled for in an analysis of covariance but students, studying either dietetics or computer sciences. this had little effect on the results. The questionnaire This ensured that one group had a greater knowledge of therefore met the criterion for construct validity. nutrition, while other variables such as age and socio- economic status were fairly similar for both groups. Ques- Internal reliability tionnaires were administered at the end of lectures on two The reliability of each section was established using Cron- separate occasions, with an interval of two weeks between bach's alpha. Correlations ranged from 0.7 ± 0.97 (see them. Two weeks was expected to be long enough for Table 5). participants to have forgotten their original responses, but not suf®ciently long for much real change in nutrition Test-retest reliability knowledge to have taken place. Participants were not Pearson's correlation was used to assess test-retest relia- aware of the intended second administration at the time bility on the scores of the 105 respondents who completed of the ®rst. Dates of birth were used to match the two sets the questionnaire twice. As shown in Table 5, the reliability of questionnaires. for each of the sections was very high, ranging from 0.8 ± The responses from the ®rst administration were used to 0.97 and the overall reliability was 0.98. assess construct validity and internal consistency. The two sets of responses were used to measure test-retest reliability. Discussion Studies aiming to assess the relationship between nutrition Results knowledge and dietary behaviour in the UK have often been criticised on the grounds of uncertain validity and At both sessions, compliance was good with almost all reliability of the instruments used to measure nutritional students present completing the measure, 168 participants knowledge (see, for example, Axelson et al, 1985; Shep- completed the questionnaire at least once, 74 dietetic herd and Towler, 1992; Anderson et al, 1988). The aim of students and 94 computer science students, 105 of these the present study was to develop a psychometrically reli- completed the questionnaire twice (53 dietetic and 52 able and valid questionnaire covering all aspects of prac- computer science students). There was a signi®cant tical nutrition knowledge which could be used in future gender difference between the two groups, with 90% of studies to look at the relationship between nutrition knowl- the dieticians being female and 84% of computer scientists edge, demographic characteristics and dietary behaviour. being male. Differences in age and ethnic origin between Signi®cant differences between the scores of the dietetic the two groups were not signi®cant. The demographic students (nutritional experts within the university environ- characteristics of the two groups are shown in Table 3. ment) and the computer scientists (who had no specialist knowledge of nutrition) indicate that the questionnaire had Table 3 Gender, age and ethnic origin of the two student samples a satisfactory construct validity, even when taking into the (n 168) account the skewed gender characteristics of the two groups. The dietetic students scored higher on all sections Dietetic students (n 74) Computer students (n 94)

Characteristic n % n %

Gender Table 5 Internal and test-retest reliability (n 168) Male 7 9.5 79 84.0 Female 67 90.5 15 16.0 Internal reliability Test-retest Age Knowledge section (Cronbach's alpha) reliability 18 ± 24 55 74.3 53 56.4 25 ± 34 17 23.0 34 36.2 Dietary recommendations 0.70 0.80 35 ± 44 2 2.7 7 7.4 Sources of nutrients 0.95 0.94 Ethnic origin Choosing everyday foods 0.76 0.87 White 57 77.0 66 70.2 Diet-disease relationship 0.94 0.97 Other 17 23.0 28 29.8 Total 0.97 0.98

Table 4 Differences in knowledge scores between dietetic and computer science students

Dietetic students (n 74) Computer science students (n 94)

Knowledge section (max score) Mean s.d. Mean s.d. F (1,167)

1. Dietary recommendations (11) 10.2 1.1 7.4 1.6 82.0* 2. Sources of nutrients (69) 62.2 5.0 40.4 11.6 134.6* 3. Choosing everyday foods (10) 9.1 1.1 5.9 2.1 81.4* 4. Diet-disease relationships (20) 17.3 2.3 6.2 3.1 321.3* Total (110) 98.8 8.1 60.1 16.1 200.5*

*P < 0.001. General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 302 of the questionnaire, and showed a particularly marked useful tool for identifying gaps in the public's nutrition superiority with regard to knowledge about the links knowledge and in evaluating the success of health educa- between diet and disease (section 4 ± see Table 4). tion campaigns. The reliability of the ®nal instrument was high. A few items which lacked consistency with the rest of the ques- Acknowledgements ÐThis research was supported by a grant from the tionnaire were retained for the sake of content validity, but Biotechnology and Biological Sciences Research Council. Acknowledge- the internal reliability remained high. The test-retest relia- ments to Jo Waller for her contribution to the writing up of the study. bility was also very good. As well as achieving statistical signi®cance in terms of validity and reliability, the initial process by which the References items were generated ensured that all aspects of the subject Anderson AS, Umapathy D, Palumbo L & Pearson DWM (1988): Nutri- area were covered, and thus the content validity, though not tion knowledge assessed in a group of medical in-patients. J. Hum. statistically measurable, was undoubtedly high. Nutr. Diet. 1, 39 ± 46. The questionnaire covers current dietary recommenda- Axelson ML, Federline TL & Birnberg D (1985): A meta-analysis of food and nutrition related research. J. Nutr. Educ. 17, 51 ± 54. tions, sources of nutrients, everyday food choices and diet- Bergman EA, Erickson ML & Boyungs JC (1992): Caffeine knowledge, disease relationships. These four areas underlie the main attitudes and consumption in adult women. J. Nutr. Educ. 24, 179 ± 184. aspects relating knowledge to dietary behaviour: Crawford DA & Baghurst KI (1990): Diet and health: a national survey of beliefs, behaviours and barriers to change in the community. Austr. J. do people know what current expert dietary recommen- Nutr. Diet. 47, 97 ± 104. dations are? Health Education Authority (1997): Eight Guidelines for a Healthy Diet. do they know which foods provide the nutrients referred London: Health Education Authority. Kline P (1986): A Handbook of Test Construction. London: Methuen. to in the recommendations? Kline P (1993): The Handbook of Psychological Testing: London, Rou- can they choose between different foods to identify the tledge. healthiest ones? Levy AS, Fein SB & Stephenson M (1993): Nutrition knowledge levels do they know what the health implications of eating or about dietary fats and cholesterol 1983 ± 1988. J. Nutr. Educ. 25, 60 ± 66. failing to eat particular foods are? McDougall P (1998): Teenagers and nutrition: assessing levels of knowl- This represents a more comprehensive assessment of edge. Health Visitor 71, 62 ± 64. Nunnally JC (1978): Psychometric Theory. 2nd edn. New York: McGraw- nutrition knowledge than has generally been achieved. Hill. Given that dietary behaviour is so complex, any attempts Resnicow K, Hearn M, Delano RK, Conklin T, Orlandi MA & Wynder EL to understand it in terms of nutrition knowledge must begin (1997): Development of a nutrition knowledge scale for elementary with a clear understanding of knowledge. Students have school students: toward a national surveillance system. J. Nutr. Educ. 28, 156 ± 164. tended either to concentrate on a speci®c area of knowledge Sapp SG & Jensen HH (1997): The reliability and validity of nutrition like fat or cholesterol, or have covered a wide variety of knowledge and diet-health awareness tests developed from 1989 ± 1991 knowledge but have not been suf®ciently systematic to gain diet and knowledge surveys. J. Nutr. Educ. 29, 63 ± 72. a true understanding of what people know. This, together Shepherd R & Towler G (1992): Nutrition knowledge, attitudes and fat with the general lack of psychometric validation of mea- intake: application of the theory of reasoned action. J. Hum. Nutr. Diet. 5, 387 ± 397. sures, may explain the variability of the results of studies Sta¯eu A, Van Staveren WA, De Graaf C & Burema J (1996): Nutrition looking at the knowledge-behaviour relationship in the area knowledge and attitudes towards high-fat foods and low-fat alternatives of nutrition. in three generations of women. Eur. J. Clin. Nutr. 50, 33 ± 41. Steenhuis IHM, Brug J, Van Assema P & Imbos Tj (1996): The validation of a test to measure knowledge about the fat content of food products. Conclusion Nutr. and Health 10, 331 ± 339. Streiner DL & Norman GR (1992): Health Measurement Scales: A This questionnaire (see Appendix 1) should provide a Practical Guide to Their Development and Use. Oxford: Oxford useful tool in research on food choice and permit a clearer University Press. understanding of the relationship between knowledge and Towler G & Shepherd R (1990): Development of a nutritional knowledge questionnaire. J. Hum. Nutr. Diet. 3, 255 ± 264. behaviour than has previously been possible. Thanks to its WHO (1990): Diet, Nutrition and the Prevention of Chronic Diseases. broad coverage in terms of content, it should also be a WHO Technical Report Series 797. Geneva: WHO.

Appendix 1 Nutrition survey This is a survey, not a test. Your answers will help identify which dietary advice people ®nd confusing.

1. It is important that you complete it by yourself. 2. Your answers will remain anonymous. 3. If you do not know the answer, mark `not sure' rather than guess. General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 303 The first few items are about what advice you think 2 Do you think these are high or low in fat? (tick one box experts are giving us per food) High Low Not sure 1 Do you think health experts recommend that people should be eating more, the same amount, or less of Pasta (without sauce) u u u Low fat spread u u u these foods? (tick one box per food) Baked beans u u u Luncheon meat u u u More Same Less Not sure Honey u u u Vegetables u u u u Scotch egg u u u Sugary foods u u u u Nuts u u u Meat u u u u Bread u u u Starchy foods u u u u Cottage cheese u u u Fatty foods u u u u Polyunsaturated margarine u u u High ®bre foods u u u u Fruit u u u u Salty foods u u u u

3 Do you think experts put these in the starchy foods group? (tick one box per food) Yes No Not sure 2 How many servings of fruit and vegetables a day do Cheese u u u you think experts are advising people to eat? (One Pasta u u u serving could be, for example, an apple or a handful Butter u u u of chopped carrots) Nuts u u u ...... Rice u u u Porridge u u u

4 Do you think these are high or low in salt? (tick one box 3 Which fat do experts say is most important for people to per food) cut down on? (tick one) High Low Not sure

(a) monounsaturated fat u Sausages u u u (b) polyunsaturated fat u Pasta u u u (c) saturated fat u Kippers u u u (d) not sure u Red meat u u u Frozen vegetables u u u Cheese u u u

4 What version of dairy foods do experts say people should eat? (tick one) 5 Do you think these are high or low in protein? (tick one box per food) (a) full fat u High Low Not sure (b) lower fat u (c) mixture of full fat and lower fat u Chicken u u u (d) neither, dairy foods should be cut out u Cheese u u u (e) not sure u Fruit u u u Baked beans u u u Butter u u u Cream u u u

Experts classify foods into groups. We are inter- ested to see whether people are aware of what foods are in these groups 6 Do you think these are high or low in ®bre=roughage? (tick one box per food) 1 Do you think these are high or low in added sugar? High Low Not sure (tick one box per food) Corn¯akes u u u Bananas u u u High Low Not sure Eggs u u u Red Meat u u u Bananas u u u Broccoli u u u Un¯avoured yoghurt u u u Nuts u u u Ice-cream u u u Fish u u u Orange squash u u u Baked potatoes with skins u u u Tomato ketchup u u u Chicken u u u Tinned fruit in natural juice u u u Baked beans u u u General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 304 7 Do you think these fatty foods are high or low in 13 There is more protein in a glass of whole milk than in a saturated fat? (tick one box per food) glass of skimmed milk.

High Low Not sure (a) agree u (b) disagree u Mackerel u u u (c) not sure u Whole milk u u u Olive oil u u u Red meat u u u Sun¯ower margarine u u u Chocolate u u u

14 Polyunsaturated margarine contains less fat than butter.

(a) agree u 8 Some foods contain a lot of fat but no cholesterol. (b) disagree u (a) agree u (c) not sure u (b) disagree u (c) not sure u

15 Which of these breads contain the most vitamins and 9 Do you think experts call these a healthy alternative to minerals? (tick one) red meat? (tick one box per food) (a) white u (b) brown u Yes No Not sure (c) wholegrain u (d) not sure u Liver pate u u u Luncheon meat u u u Baked beans u u u Nuts u u u Low fat cheese u u u Quiche u u u 16 Which do you think is higher in calories: butter or regular margarine? (tick one)

(a) butter u (b) regular margarine u 10 A glass of unsweetened fruit juice counts as a helping (c) both the same u of fruit. (d) not sure u

(a) agree u (b) disagree u (c) not sure u

17 A type of oil which contains mostly monounsaturated fat is: (tick one)

11 Saturated fats are mainly found in:(tick one) (a) coconut oil u (b) sun¯ower oil u (c) olive oil u (a) vegetable oils u (d) palm oil u (b) dairy products u (e) not sure u (c) both (a) and (b) u (d) not sure u

18 There is more calcium in a glass of whole milk than a 12 Brown sugar is a healthy alternative to white sugar. glass of skimmed milk.

(a) agree u (a) agree u (b) disagree u (b) disagree u (c) not sure u (c) not sure u General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 305 19 Which one of the following has the most calories for 3 Which kind of sandwich do you think is healthier? (tick the same weight? (tick one) one)

(a) sugar u (a) two thick slices of bread with a thin slice u (b) starchy foods u of cheddar cheese ®lling (c) ®bre=roughage u (b) two thin slices of bread with a thick slice u (d) fat u of cheddar cheese ®lling (e) not sure u

4 Many people eat spaghetti bolognese (pasta with a 20 Harder fats contain more: (tick one) tomato and meat sauce). Which do you think is heal- (a) monounsaturates u thier? (tick one) (b) polyunsaturates u (c) saturates u (a) a large amount of pasta with a little sauce on top u (d) not sure u (b) a small amount of pasta with a lot of sauce on top u

5 If a person wanted to reduce the amount of fat in their 21 Polyunsaturated fats are mainly found in: (tick one) diet, which would be the best choice? (tick one) (a) vegetable oils u (b) dairy products u (a) steak, grilled u (c) both (a) and (b) u (b) sausages, grilled u (d) not sure u (c) turkey, grilled u (d) pork chop, grilled u

The next few items are about choosing foods Please answer what is being asked and not whether you 6 If a person wanted to reduce the amount of fat in their like or dislike the food! diet, but didn't want to give up chips, which one would For example, suppose you were asked ...... be the best choice? (tick one) `If a person wanted to cut down on fat, which cheese (a) thick cut chips u would be best to eat?' (b) thin cut chips u (a) cheddar cheese (c) crinkle cut chips u (b) camembert (c) cream cheese (d) cottage cheese If you didn't like cottage cheese, but knew it was the right answer, you would still tick cottage cheese. 7 If a person felt like something sweet, but was trying to 1 Which would be the best choice for a low fat, high ®bre cut down on sugar, which would be the best choice? snack? (tick one) (tick one) (a) diet strawberry yoghurt u (a) honey on toast u (b) raisins u (b) a cereal snack bar u (c) muesli bar u (c) plain Digestive biscuit u (d) wholemeal crackers and cheddar cheese u (d) banana with plain yoghurt u

2 Which would be the best choice for a low fat, high ®bre 8 Which of these would be the healthiest pudding? (tick light meal? (tick one) one)

(a) grilled chicken u (a) baked apple u (b) cheese on wholemeal toast u (b) strawberry yoghurt u (c) beans on wholemeal toast u (c) wholemeal crackers and cheddar cheese u (d) quiche u (d) carrot cake with cream cheese topping u General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 306 9 Which cheese would be the best choice as a lower fat If yes, what diseases or health problems do you think are option? (tick one) related to sugar? ...... (a) plain cream cheese u ...... (b) Edam u ...... (c) cheddar u (d) Stilton u

4 Are you aware of any major health problems or diseases that are related to how much salt or sodium people eat? 10 If a person wanted to reduce the amount of salt in their diet, which would be the best choice? (tick one) (a) yes u (b) no u (a) ready made frozen shepherd's pie u (c) not sure u (b) gammon with pineapple u (c) mushroom omelette u (d) stir fry vegetables with soy sauce u If yes, what diseases or health problems do you think are related to salt? ...... This section is about health problems or diseases ...... 1 Are you aware of any major health problems or diseases that are related to a low intake of fruit and vegetables?

(a) yes u 5 Are you aware of any major health problems or diseases (b) no u that are related to the amount of fat people eat? (c) not sure u (a) yes u (b) no u (c) not sure u If yes, what diseases or health problems do you think are related to a low intake of fruit and vegetables? ...... If yes, what diseases or health problems do you think are ...... related to fat? ......

2 Are you aware of any major health problems or diseases that are related to a low intake of ®bre? 6 Do you think these help to reduce the chances of getting (a) yes u certain kinds of cancer? (answer each one) (b) no u (c) not sure u Yes No Not sure eating more ®bre u u u eating less sugar u u u eating less fruit u u u eating less salt u u u If yes, what diseases or health problems do you think are eating more fruit and vegetables u u u related to sugar? eating less preservatives/additives u u u ...... 7 Do you think these help prevent heart disease? (answer each one)

3 Are you aware of any major health problems or diseases Yes No Not sure eating more ®bre u u u that are related to how much sugar people eat? eating less saturated fat u u u eating less salt u u u (a) yes u eating more fruit and vegetables u u u (b) no u eating less preservatives/additives u u u (c) not sure u General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 307 8 Which one of these is more likely to raise people's 4 What is your ethnic origin? blood cholesterol level? (tick one) (a) White u (a) antioxidants u (b) Black Caribbean u (b) polyunsaturated fats u (c) Black African u (c) saturated fats u (d) Black other u (d) cholesterol in the diet u (e) Indian u (e) not sure u (f) Pakistani u (g) Bangladeshi u (h) Chinese u (i) Asian ± other u Please specify: ...... j) Any other ethnic group u 9 Have you heard of antioxidant vitamins? Please specify: ...... (a) yes u (b) no u

5 Do you have any children?

(a) No u 10 If YES to question 9, do you think these are anti- (b) 1 u oxidant vitamins? (answer each one) (c) 2 u (d) 3 u (e) 4 u Yes No Not sure (f) more than 4 u Vitamin A u u u B Complex Vitamins u u u Vitamin C u u u Vitamin D u u u Vitamin E u u u Vitamin K u u u 6 Do you have any children, under 18 years, living with you?

(a) Yes u (b) No u Finally, we would like to ask you a few questions about yourself 1 Are you male or female? 7 What is the highest level of education you have completed? (a) Male u (b) Female u (a) primary school u (b) secondary school u (c) O levels/GCSEs u (d) A levels u (e) Technical or trade certi®cate u (f) Diploma u (g) Degree u 2 How old are you? (g) Post-graduate degree u

(a) less than 18 u (b) 18 ± 24 u (c) 25 ± 34 u (d) 35 ± 44 u 8 Do you have any health or nutrition related quali®ca- (e) 45 ± 54 u (f) 55 ± 64 u tions? (g) 65 ± 74 u (h) more than 75 u (a) Yes u Please specify: ...... (b) No u

3 Are you: 9 What is your job? If you are not working now, what is (a) single u (b) married u your usual job? (please be speci®c). (c) living as married u (d) separated u ...... (e) divorced u (f) widowed u ...... General nutrition knowledge questionnaire for adults K Parmenter and J Wardle 308 10 If you have a partner, what is his/her job? If he/she is THE END not working now, what is his/her usual job? (please be speci®c): Thank you very much for your time. If there are any comments you would like to make ...... about this questionnaire, please do so below, they would be very welcome......

11 Are you currently: ......

(a) employed full time u ...... (b) employed part time u (c) unemployed u ...... (d) full time homemaker u (e) retired u ...... (f) student u (g) disabled or too ill to work u ......

......

12 Are you on a special diet? ......

(a) Yes u ...... Please specify: ...... (b) No u ......