Biostatistical Analysis on the Consideration of Nutrition-Related Modules in the Higher Education Curriculum

Participants

Participants were first year undergraduate students studying a mandatory course from across seven different schools and scientific disciplines at a remote campus. None of the students have studied a food or nutrition- related module before or during the study. With 95% confidence level and 5% confidence interval, out of 5403 undergraduate students, the sample size was found to be 359. A total of 378 students participated in the intervention and completed the nutrition knowledge test (response rate 56.6%). For the re- test, the response rate was 26.2%.

Intervention

The intervention, which took place in March-April 2017, included the preparation and presentation of healthy snacks and accompanying informative leaflets to the participants on a weekly basis for four weeks. Four key recommendations from the dietary guidelines that are listed below were assigned to each week of the intervention: Week 1- Eat more dietary fibre Week 2- Eat less sodium Week 3- Eat less sugar Week 4- Eat less saturated fats and trans-fats [18]. Nutrition knowledge test was administered before and after the intervention.

Snack food preparation and nutritional analysis Snack foods were produced at a reasonable cost for students but offered free of charge during the intervention. The procedures for preparing the healthy snacks were as follows: a) Reviewing current recipes of healthy snacks b) Choosing healthy ingredients and modifying the recipes c) Nutritional and cost analysis d) Preparation of snacks e) Storage and distribution of snacks The healthy snacks produced were: Week 1- “hot-dry noodles” and “strawberry banana muffin”; week 2-“pumpkin and spinach muffin” and “crackers with seeds and yogurt dip”; week 3-“nut and dried fruit bar” and “strawberry banana smoothie”; week 4-“banana bread” and “bulgur (cracked wheat) served with yogurt”. All ingredients were obtained by the purchasing department of the school. The snacks were prepared in the kitchens of the school by the researchers. They were individually packaged, labeled and stored at 4-8°C before being delivered to the classrooms. The classes, comprising of 8 to 35 students, were taught by different lecturers on different days and times. Lecturers were requested to encourage students to consume the snacks and read the leaflets at a convenient time (i.e. either during the lectures or at break times).

Informative Leaflets: Both sides of a coloured A4 size paper were used for each leaflet (Supplementary file 1). The leaflets were delivered to the classrooms together with the healthy snacks. Both were presented to the students whenever deemed suitable by lecturers. Informative leaflets included: a) Sources of the nutrient of concern (dietary fibre, salt, sugar etc.) b) Effects of the nutrient on health c) Healthy eating tips to increase or reduce the daily intake d) Recommended daily amounts e) The recipe and preparation method (these were included in an attempt to encourage students to prepare/cook their own food) f) Nutrition labels, ingredient listing, production date and cost per portion (cost was included to demonstrate that it was possible to prepare healthy snacks at a reasonable price. Research has shown this was usually one of the most important factors determining the purchasing decision of snack foods in an educational setting [19]).

Questionnaire

The questionnaire items that are relevant to the themes of the intervention were taken from Bin Zhao [20]. There were 14 items relevant to dietary fibre, 13 items for salt, 12 items for sugar and 36 items for fat. There were 22 items that were not directly relevant to the themes but these were retained to measure some aspects of general nutrition knowledge before and after the intervention. The last part of the questionnaire included personal and anthropometric information (i.e. height and weight). The language of the questionnaire was English. The questionnaire was paper- based and administered in the presence of the lecturers. Participants completed the questionnaire anonymously.

Ethical Approval

Ethical approval was granted from the Ethics Committee of the University. Participation was voluntary and all participants filled in the ‘Participation consent form’.

Biostatistical Analysis

Biostatistical analyses were conducted using the Statistical Package for Social Sciences, SPSS (IBMCorp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp.), with statistical significance set at p<0.05. The raw data from each participant’s responses were coded numerically. The responses were converted to 1 to 0 for correct and incorrect answers, respectively (‘not sure’ responses were also coded as incorrect). Descriptive statistics were used to analyse the demographic information and frequency tables. Parametric tests (t-test), non- parametric tests (Kruskal-Wallis test) and chi-square tests were used when necessary.

Participant Characteristics

Among the participants who declared their gender (65.6%), 36.2% were male and 29.4% were female. The body mass index (BMI) of the participants was calculated by dividing the weight (kg) by the square of the height (m2) and categorised as < 18.5 underweight, between 18.5 and 24.9 normal, between 25.0 and 29.9 overweight and ≥ 30 obese (18). It was found that 7.4% of the participants were underweight, 55.6% were normal weight, 16.9% were overweight and 4.5% were obese (data not shown) [21].

Nutrition Knowledge before the Intervention

Items answered correctly by most of the participants: The number and description of the most correctly answered items were: A8.1 Chicken has high protein content. This was the most correctly answered item (91.5%). A27.1 Obesity is related to fat consumption (86.2%). A10.1 Trans-fatty acid (TFA) content of margarine is high (85.4%). Items mostly answered incorrectly: A1.3 Most of the participants thought that experts suggested to eat more or the same amount of meat (89.7%). However, dietary guidelines suggest a diet which reduces the amount of meat consumption while including a greater variety of other protein sources (legumes, seafood, dairy products and nuts) [18]. Moreover, the consumption of processed meat and meat products has been shown to cause cancer in humans [22] and this information has been disseminated widely by relevant media including the Ministry of Health publications.

A2 the majority of the participants (71.4%) selected the option of eating less than the advised 5 portion of fruit and vegetables in a day, plus 18.3% of the participants were unsure of the correct answer. A previous study showed similar findings, where the adult participants knew the importance of increasing their intake of fruits and vegetables but were unaware of the number of daily portions [23].

A19 Most participants (61.1%) answered the item about the energy contents of the foods incorrectly. 30.2% of participants thought that simit (type of bagel covered with sesame seeds) had the lowest energy content (when compared to baked apple, strawberry yogurt and vanilla ice cream). This was similar to the findings of another study where most participants answered the item on the energy content of the macronutrients incorrectly [23].

Items participants were mostly unsure of: A24.5 53.2% of the participants was unsure of the relationship between cirrhosis and the intake of fruit and vegetables. A3 48.7% were unsure which type of fat (monounsaturated, polyunsaturated and saturated) experts say is the most important for people to reduce intake. This item measured ‘factual/declarative knowledge’ and it contained scientific terms that the participants were mostly unfamiliar with. A27.4 45.0% was unsure whether there was a relationship between constipation and fat consumption.

Nutrition Knowledge after the Intervention

The following items, whose correct answers were listed below, had a significant change in the distribution of responses (correct, incorrect and unsure) after the intervention (Table 1).

Salt (1 item) Kippers are high in salt (A7.3).

Sugar (2 items) Pomegranate sauce (processed, not fresh) is high in sugar (A5.1). Brown sugar is not a healthy alternative to white sugar (A13).

Saturated fat and trans-fat (5 items) Saturated fat is the most important for people to reduce intake (as recommended by experts) (A3).

Pasta without sauce is low in fat (A6.1).

Cheddar cheese is high in saturated fat (A11.4). Constipation is not related to fat consumption (A27.4).

Eating less saturated fat can prevent heart disease (A28.4).

General items (3 items) Health experts recommend that people should be eating more vegetables (A1.1).

Experts are advising people to eat 5 servings of fruits and vegetables a day (A2).

There is not more calcium in a glass of whole milk than a glass of skimmed milk (A15).

When the items belonging to the same theme were grouped and analysed, no significant differences were observed in the distribution of responses (i.e. correct, incorrect and unsure) for “dietary fibre”, “salt”, “sugar” and “general items” after the intervention (Table 2). However, the change in the distribution of the responses relevant to “less saturated fat and trans-fat” was found to be biostatistically significant (p<0.05). 21 items (58.3%) within this category had an increase in the correct responses after the intervention.

The question items relevant to “less saturated fat and trans- fat” included: a) Experts` recommendation of type of fat to cut down b) Identification of foods that are high and low in fat c) Identification of foods that contain trans-fatty acids d) Comparison of the saturated fatty acid content of fats and oils, e) The best choice for a low fat-high fibre snack, f) Comparison of the percent energy provided by butter versus sunflower oil g) Diseases related to fat consumption and h) Eating less saturated fat preventing heart disease.

Some items in Table 1 were incorrectly answered by most of the participants even after the intervention. These items were A1.3 (81.7%), A2 (70.3%) and A13 (51.4%). Item A1.3 (experts recommend people to eat less meat) was not referred to in any of the leaflets. Item A2 (eating 5 servings of fruits and vegetables) was mentioned briefly at the end of each leaflet as a reminder. Due to the repetition of this information, a greater percentage of correct answers were anticipated than obtained. Item A13 (brown sugar is a healthy alternative to white sugar) was mentioned once in the “Eat less sugar” leaflet. This specific information possibly did not catch the attention of the participants.