CHAPTER 4: The anthropometric and socio-demographic characteristics, and levels of nutrition
4.4 Results
4.4.5 Nutrition knowledge levels
results all positive opinions have been conflated into “agree” and negative opinions into
“disagree” with neutral opinions remaining as they are. The results show that the most popular statements that the learners agreed with were “this is my favourite thing to eat or drink” (66.5%, n = 177) and “I only have enough money to buy this” (47.0%, n = 125). Learners felt most strongly against the statements “I don’t like what I brought from home” (66.9%, n = 178) and “I am not allowed to have this at home”.
Table 4.9: Reasons why learners purchase specific tuck shop items
Agree Disagree Neutral Not
answered
n % n % n % n %
This item is my favourite thing to eat or
drink 177 66.5 36 13.5 27 10.2 26 9.8
I only have enough money to buy this
item / these items 125 47.0 71 26.7 44 16.5 26 9.8
The person looking after me has told me that I am only allowed to buy this item / these items
70 26.3 122 45.9 54 20.3 20 7.5
My friends by this item 64 24.1 146 54.9 35 13.2 21 7.9
I think this item will help keep my body
healthy 66 24.8 122 45.9 49 18.4 29 10.9
I don’t like what I brought for lunch from
home 30 11.3 178 66.9 30 11.3 28 10.5
I am not allowed to eat or drink this item
at home 53 19.9 173 65.0 16 6.0 24 9.0
When asked to rank the top three “statements” influencing tuck shop purchases, “this is my favourite thing to eat or drink” was rated the most influential (24.1%, n = 75), followed by a tie with the options “this is my favourite thing to eat and drink” and “I only have enough money to buy this item” (9.6%, n = 30). “My friends buy this item” was rated as the third most important reason to purchase from the tuck shop (11.6%, n = 36).
12.7 out of 26 (48.8%). Analysis of Variance (ANOVA) revealed no significant difference between knowledge scores of male and female learners.
Table 4.10: Total scores for each section of the nutrition knowledge test Number
Questions of
n Minimum
Score Maximum
Score Mean Std
Deviation
Total score for knowledge 26 310 3 21 12.70 3.788
Food Groups score 6 310 0 5 1.99 1.061
Fruit & Veg servings per day 1 310 0 1 0.33 0.471
Healthy fats 8 310 0 8 4.56 1.909
Fat True or False 3 310 0 3 1.63 1.062
Fat functions 3 310 0 3 1.03 0.741
Fibre functions 2 310 0 2 0.92 0.682
Sugar True or False 3 310 0 3 2.28 0.966
Additional analyses showed that the total knowledge scores of those learners that reported never buying from the tuck shop had a tendency to be higher when compared to the total knowledge scores of those learners who bought from the tuck shop (12.6 ± 3.8and 13.0 ± 3.72, respectively).
Linear regression analysis also revealed that the total knowledge scores contributed significantly towards the BMI of the group as a whole (significance < 0.000). Further analyses also showed that the total knowledge scores of those learners that reported purchasing from the tuck shop frequently, was significantly (p < 0.05) lower when compared to the total knowledge scores of those learners who bought from the tuck shop less frequently (13.0 ± 3.9 and 11.6 ± 3.1, respectively). Logistic regression analysis confirmed that the total knowledge of a learner can be used to predict whether he or she is more likely to purchase items from their school tuck shop (significance = 0.017), in that higher levels of knowledge result in decreased frequency of tuck shop purchases.
Table 4 .11: Correct and incorrect answers to nutrition knowledge questions
Correct Incorrect Obese Correct
n % n % n %
Food Groups (Multiple Choice)
Food group that you should eat the most 36 11.6 275 88.4 12 14.1
Food group that you should eat the least 257 82.6 54 17.4 68 80.0
Food group that contains foods with lots of fibre 60 19.3 251 80.7 13 15.3
Food group that provides the best energy 46 14.8 265 85.2 14 16.5
Food group that your body uses to build muscles 57 18.3 254 81.7 10 11.8 Food group that protects the body against illness 163 52.4 148 47.6 38 44.7
Average for food group questions 103 33.2 208 66.8 26 30.6
Fruit and Vegetables (Multiple Choice)
Number of recommended fruit and veg portions 102 32.8 209 67.2 25 29.4 Fats (True or false)
Fats give energy and keep you warm (true) 62 19.9 249 80.1 24 28.2 Fats help with absorption of nutrients (true) 75 24.1 236 75.9 14 16.5 Fats help your body to build muscle (false) 180 57.9 131 42.1 53 62.4
Too much fat causes overweight (true) 234 75.2 77 24.8 73 85.9
Too much fat causes high blood pressure (true) 138 44.4 173 55.6 39 45.9 Too much fat can cause a heart attack (true) 132 42.4 179 57.6 34 40.0
Average for fats 137 44.0 174 56.0 40 47.1
Healthy Fats (True or False)
Healthy fats in red meat and chicken 100 32.2 211 67.8 28 32.9
Healthy fats in chips and crisps 244 78.5 67 21.5 66 77.6
Healthy fats in nuts 220 70.7 91 29.3 58 68.2
Healthy fats in soft margarine 95 30.5 216 69.5 24 28.2
Healthy fats in avocado 241 77.5 70 22.5 69 81.2
Healthy fats in vetkoek and doughnuts 232 74.6 79 25.4 69 81.2
Healthy fats in pilchards and sardines 193 62.1 118 37.9 54 63.5
Healthy fats in polony 88 28.3 223 71.7 25 29.4
Average for healthy fats 177 56.8 134 43.2 49 57.6
Sugar (True or False)
Eating a lot of sugar and sweet food is good for health 237 76.2 74 23.8 65 76.5 Eating a lot of sugar and sweet food can make you fat 209 67.2 102 32.8 63 74.1 Eating a lot of sugar and sweet food is bad for your teeth 257 82.6 54 17.4 68 80.0
Average score for sugar 234 75.3 77 24.7 65 76.5
Fibre (True or False)
Fibre helps you go to the toilet regularly 139 44.7 172 55.3 44 51.8 Fibre helps protect against heart disease 145 46.6 166 53.4 34 40.0
Average for fibre 142 45.7 169 54.3 39 45.9
Average Total score for knowledge 152 48.8 159 51.2 41 48.2
When looking at the average for the food group questions as well as the recommended number of fruit and vegetable servings per day question, just under two thirds of the sample (n=208, 66.8%) had incorrect results. This also included the obese learners where on average only one third of these learners answered these questions correctly. The questions surrounding sugar were the most well answered on average with 75.3% of learners answering correctly. Interestingly, obese learners performed similarly on the sugar questions when compared to the whole sample (76.5%
answering correctly).
A combination of all the factors in relation to the BMI percentiles is presented in Table 4.12.
Learners in the highest quartile range were most likely to visit their tuck shop and purchase frequently, including every day. Learners in the lowest BMI quartile spent more money, but were most likely to purchase non-frequently and once a week. Learners who achieved the highest knowledge scores were in the normal BMI categories.
Table 4.12: Learner characteristics in relation to BMI percentiles
BMI Percentiles <25 (n - ) 50 percent band >25
Money spent per day R8.86 R8.47 R7.73
Knowledge score (out of 26):
Fat (out of 6) Sugar (out of 3) Fibre (out of 2) Healthy Fats (out of 8)
12.30 1.38 2.29 0.96 4.29
12.99 1.71 2.24 0.91 4.78
12.53 1.73 2.34 0.88 4.43 Do they purchase from the tuck shop?
Yes No 86.3
13.8 84.4
15.6 87.0
13.0 Non-frequent purchasers
Frequent purchasers 66.3
18.8 66.2
16.9 64.9
22.1 Tuck shop visits per week:
Once Twice Three times Four times Every day
Don’t go to the tuck shop
48.8 5.0 6.3 5.0 7.5 13.8
48.7 10.4 3.9 9.1 15.6 10.0
39.0 22.1 3.9 2.6 15.6 13.0 Presence of medical condition:
Diabetes Blood Pressure Cholesterol Heart disease Obesity
1.3 2.5 0.0 2.5 0.0
1.9 5.8 2.6 0.0 2.6
2.6 2.6 1.3 1.3 14.1
Consumption of breakfast 90.0 92.9 90.9
Resources:
Newspaper Magazine Radio TV Computer Stove Internet DVD Fridge Electricity Flushing Toilet Landline
78.8 76.3 91.3 97.5 86.3 65.0 100 97.5 96.3 97.5 100 67.5
80.5 70.1 94.2 89.0 100 61.0 100 98.7 96.8 99.4 98.7 72.0
80.5 72.7 96.1 89.6 100 63.6 100 94.8 93.5 98.7 98.7 75.3