Effectiveness of a school-based nutrition and food safety education program among primary and junior high school students in Chongqing,China

Abstract

Background:

Health behavioral patterns, especially eating patterns, established in childhood often carry over into adulthood, and some of the unhealthy ones are later associated with adult morbidity and mortality. Recently, a few nutrition and food safety education programs have been implemented in primary and junior high schools in China.

Purpose:

This study aims to examine the effectiveness of a school-based nutrition and food safety education program among primary and junior high school students in China.

Methods:

A mixed study design incorporating an intervention study and a quantitative survey was conducted for this research. With stratified cluster sampling, students from the 5^th and 6^th grade in one primary school and the 7^th and 8^th grade in one junior high school in Chongqing, China, were all selected and separated randomly into an intervention group (n = 501) and a control group (n = 522). Effectiveness evaluation investigations were performed at the initial time and nine-month follow-up (n = 472), respectively. Effectiveness of pre-/post-intervention and nine-month follow-up changes in scores of nutrition knowledge and food safety was assessed using a two-tailed t-test and analysis of variance.

Results:

Nutrition knowledge scores for the intervention group were mean 9.03, SD±2.75 at the baseline, and 14.70±3.28 after intervention. There was a significant improvement (t = 29.78, p < 0.01). The nine-month follow-up knowledge scores of the intervention group were 12.35±2.89, which were lower than the immediately after the intervention group (t = 12.40, p<0.01), but higher than those of the baseline level (t = 18.04, p < 0.01). Food safety scores of the post-intervention were higher (p < 0.01) than that of the control group in both pre-intervention and nine-month follow-up. The control group had no significant change in the pre-post intervention.

Conclusions:

It is feasible and effective to improve nutrition and food safety knowledge among primary and junior high school students through school-based nutrition and food safety education programs.

Keywords

nutrition education nutrition knowledge school-based nutrition effectiveness evaluation nutrition association

Introduction

Healthy and balanced nutrition has a significant effect on students’ physical and mental development. Based on the data from different studies, healthy nutrition greatly influences our health (1). Nutrition-related health problems in children are increasingly significant causes of disability and premature death worldwide. On the other hand, the markets offer children and adolescences more attractive foods, which have a low dietary value; canteens of schools are being privatized; prices of foods are increasing; and less attention is given to nutrition because of increased involvement of students in school activities (2). Research findings show that school-based programs can play a significant role in promoting lifelong healthy eating, and much research evidence links intention to eat an improved diet with actual behavior (3 –8).

Therefore, it is critically important for primary and junior high school students to improve the level of nutrition and food safety cognition. Numerous studies have demonstrated that nutrition education is one of the most cost-effective methods to improve the nutritional cognition and status of primary and junior high school students (9 –12). School-based nutrition education is particularly important as children and adolescents frequently decide what to eat with little adult supervision (13). Besides, nutrition education resources in primary and secondary schools are limited, especially in developing countries where some schools rarely provide a health education curriculum and the students lack the basic understanding of both nutrition and food safety knowledge (11,14 –20). Hence, it is extremely necessary to enrich nutrition education resources in order to develop more effective nutrition education in primary and junior high schools.

On the other hand, there is abundance of nutrition education resources in the universities (20), especially in medical universities. The nutrition education resources are not only professors and experts of nutrition and food safety, but also students who have majored in nutrition, who have enthusiasm and a solid foundation of nutrition and food hygiene knowledge. Therefore, it is worth considering how to mobilize and exploit college nutritional education resources to improve the education of primary and secondary school students. Several nutrition and food safety education programs have been carried out in primary and junior high schools. The programs were designed by nutrition experts in Chongqing Medical University and implemented by medical college students. The main objective of this research was to assess the effectiveness of a school-based nutrition and food safety education program among primary and junior high school students in China. The assessment focused on nutrition and food safety knowledge–behavior–change in attitude (KAP) at pre-/post-intervention and nine-month follow-up.

Methods

Participants

The research project was conducted from October 2011 to June 2012. One primary school and one junior high school were selected by computer generated randomization with stratified cluster sampling. Students from the 5^th and 6^th grades in the primary school and the 7^th and 8^th grades in the junior high school were chosen for this study. A total of 1058 students (12 classes) were recruited to participate in the baseline study. After baseline investigation, all the students of grades 5 and 6 in the primary school and all students of grades 7 and 8 in the junior high school were selected by computer generated randomization, and each grade was randomly selected from three classes (making 12 classes in total) as the intervention group (n = 501, consisting of 256 boys and 245 girls); the rest were the control group (n = 522, consisting of 261 boys and 261 girls). After nine months, a follow-up investigation was conducted in the intervention groups (n = 472, consisting of 235 boys and 237 girls). Compared with the immediately after data, the dropout rate was 5.79%. There was no significant difference in gender, age, nationality, and sibling numbers between the pre-/post-intervention and nine-month follow-up (p > 0.05).

Questionnaires

Based on a related literature questionnaire on nutrition and food safety knowledge among primary and junior high school students, the questionnaire used throughout this study, which was self-designed, had good validity, reliability, and readability (18,19). The questionnaire was based on the KAP model, designed specifically for the target population, and completed after repeated discussions and pre-survey, which included four sections: basic information; nutrition knowledge; eating habits, attitude, and behavior; and food safety knowledge.

Ethics

This study was approved by the Ethics Committee, Chongqing Medical University. Written informed consent was obtained from all participants.

Procedures

Our educational interventions consisted of both lectures and a prize quiz game about nutrition and food safety.

Lectures about nutrition education

On the basis of the baseline assessment and input from experts, professors, and students of the department of nutrition and food hygiene of Chongqing Medical University, the lectures were jointly designed with contents of nutrition and food safety knowledge. The main content of the lectures included nutrition knowledge, good personal eating habits, the prevention of nutrient deficiency diseases, food safety issues, etc. Nutrition lectures were given to the six intervention groups by six senior medical college students, whose major was nutrition and had been strictly trained (we drafted a slideshow and a prospectus to guide the undergraduates in how to give the lectures) many times. Lectures were planned for 30 minutes; in addition, each class was arranged by two supervisors and had finished a preceding evaluation. At the same time, the control groups did not receive any intervention.

Prize quiz game

After the lecture, two nutrition-related prize quiz games were organized in each class, including a game of Chinese food guide pyramid, good personal eating habits, and a game of the prevention of nutrient deficiency diseases, food safety issues. Each game was scheduled for 10 minutes and two supervisors as reviewers were assigned to grade the answers. Depending on the students’ scores, the two supervisors gave out the awards.

Survey implementation

Before measures were taken, we launched a pre-survey among 220 school students in each grade, and just selected one class from every grade for the survey. According to this survey, we found that students had poor knowledge of nutrition and food safety, suggesting that measures should be taken to control this particular troublesome situation. After the pre-survey, an investigation was carried out after an explanation of the purpose of the research by investigators who had undergone unified rigorous training for two years, and were familiar with the objectives and methodology. The questionnaire was executed after the intervention. Each class was allocated two investigators who had received instruction regarding the questionnaire for six hours and the investigators were standardized in answering any of the students’ questions if explanations were needed. Another two well-trained supervisors assessed the process of the intervention and investigation in the class. It took about 20 minutes to complete the questionnaires.

Assignment method of nutrition knowledge scores

The questionnaire on nutrition knowledge, which contained 16 questions in total (13 solo choice items and three multiple choice items), was used to comprehensively assess the level of students’ nutritional knowledge. Each item had one score. As to the three multiple-choice items, all responses were structured in different ways according to how each question was answered, and each question had four distinct responses, with the score ranging from zero to three. Maximum score of nutrition cognition was 22.

Assignment method of the food safety knowledge scores

The part on food safety knowledge consisted of eight questions in total. An assignment method was used to arrive at the comprehensive score of the students’ food safety knowledge. Each question could be directly judged as true or false; the correct answer was assigned two points, and wrong or no answers were assigned 0 points. If the subject’s answers were progressive relations, 1, 2, or 3 were assigned according to the progressive relationship; did not know or no answer were assigned 0 points. Finally, the investigators calculated the total score so as to comprehensively evaluate the nutrition knowledge level of participants. The total score of this section was 19.

Data analyses

Data from the questionnaire-based inquiry were stored, after a strict sorting and data cleaning, and analyses were performed by statistical analysis system software (version 9.0; SAS Institute, Cary, NC). Missing data were excluded and all data entries were double-checked to avoid errors. Outcomes were evaluated at baseline, at post-intervention, and at follow-up. Demographic characteristics of participants, awareness rate of nutrition knowledge, and the section on eating habits used χ² tests. Evaluation of before/after and nine-month follow-up changes in scores of nutrition knowledge and food safety were performed by a two-tailed t-test and analysis of variance (any two groups compared with LSD method). All the statistics were predetermined as p-value < 0.05 for statistical significance.

Results

Sample demographics

A total of 1023 participants were organized into intervention (n = 501) and control (n = 522) groups. The demographic characteristics of the participants are presented in Table 1. There was one significant difference between groups (single child status in the primary school group) (χ2 = 4.84, p = 0.03). There were no significant differences with respect to participants’ age, gender, nationality, and sibling numbers between the intervention group and control group of study students.

Table 1.

The demographic characteristics of the intervention group and the control school students, China, 2011.

Variables	Primary school students (n = 518)				Junior high school students (n = 505)
Variables	Intervention	Control	χ²	p	Intervention	Control	χ²	p
Age (year)			4.34	0.23			7.72	0.05
≤10	96	100			1	0
11	116	115			5	5
12	48	33			77	73
13	3	5			115	117
14	0	2			38	64
≥15	0	0			2	8
Gender			0.38	0.54			0.01	0.92
Boy	134	123			122	138
Girl	129	132			116	129
Nationality			–	0.51			–	0.67
Han	241	249			227	263
Others	3	6			3	2
The only child			4.84	0.03^a			1.80	0.18
Yes	176	146			148	154
No	79	99			80	107

The difference between the intervention group of primary school students and the control group was statistically significant (p < 0.05).

Nutrition knowledge

Immediately after the intervention, most of the awareness rates of nutrition knowledge improved significantly, with more than 10% having some knowledge of nutrition, such as about fats, proteins, and calcium. Moreover, awareness rates of the question ‘what kind of disease is salt ionization used to prevent’ rose to 70.30% (χ² = 306.66, p < 0.01) (Table 2). The most significant improvement was the students’ understanding of the Chinese food guide pyramid.

Table 2.

Comparison of the awareness rate of nutrition among the intervention group and the control group, China, 2011–2012.

Nutrition knowledge	Primary school students					Junior high school students
Nutrition knowledge	Intervention group			Control group		Intervention group			Control group
	B(273)	I(263)	L(253)	B(269)	I(255)	B(242)	I(238)	L(219)	B(274)	I(267)
Protein^{a b}	0.49^▼	0.63^{* * △ △}	0.57^{* * △ △}	0.37^▼	0.47^*	0.52	0.53	0.67^{* * △ △}	0.51	0.53
Fat^b	0.89	0.92	0.95^{* △}	0.87	0.89	0.92	0.92	0.94	0.94	0.94
Vitamin C^{a b}	0.90	0.90^{△ △}	0.95^{* △ △}	0.862	0.820	0.89	0.84	0.93^*	0.91	0.90^△
Calcium ^b	0.24	0.39^{* * △ △}	0.24	0.18	0.19	0.24	0.40^{* * △ △}	0.41^{* * △ △}	0.18	0.21
Coronary disease (fat)^a	0.26	0.48^{* * △ △}	0.44^{* * △ △}	0.26	0.28	0.28	0.43^{* * △ △}	0.45^{* * △ △}	0.28	0.29
Anemia (Ferrum)	0.23	0.48^{* * △ △}	0.32^{* * △ △}	0.20	0.22	0.22	0.53^{* * △ △}	0.34^{* * △ △}	0.20	0.20
Rickets (Vitamin D)	0.18	0.67^{* * △ △}	0.32^{* * △}	0.15	0.24^*	0.19	0.55^{* * △ △}	0.30^{* * △ △}	0.16	0.18
Scurvy (Vitamin C)	0.08	0.55^{* * △ △}	0.18^{* *}	0.12	0.13	0.18	0.43^{* * △ △}	0.29^{* * △ △}	0.17	0.18
Goiter (iodine)^b	0.23	0.91^{* * △ △}	0.78^{* * △ △}	0.19	0.24	0.34	0.70^{* * △ △}	0.69^{* * △ △}	0.31	0.39^*
Diet pagoda	0.43	0.94^{* * △ △}	0.80^{* * △ △}	0.38	0.42	0.27	0.91^{* * △ △}	0.75^{* * △ △}	0.31	0.33
Five layers pagoda	0.25	0.90^{* * △ △}	0.53^{* * △ △}	0.19	0.26^*	0.15	0.83^{* * △ △}	0.64^{* * △ △}	0.15	0.17
The bottom layer	0.11	0.62^{* * △ △}	0.28^{* * △ △}	0.12	0.15	0.09	0.71^{* * △ △}	0.50^{* * △ △}	0.07	0.10
Best amount of fat	0.37	0.86^{* * △ △}	0.76^{* * △ △}	0.34	0.37	0.25	0.85^{* * △ △}	0.69^{* * △ △}	0.29	0.31

B: Baseline, I: Instant, L: Long-term;

▼

: The difference between the baseline intervention group of primary school students and the baseline intervention group of junior high school students was statistically significant(χ² = 7.37, p < 0.01);

: Before-after comparison of the instant intervention group and baseline intervention group, and the long-term intervention group and baseline intervention group (p < 0.05,^{* *} p < 0.01);

△

: Comparison of the baseline intervention group and baseline control group, and the baseline intervention group and instant intervention group (p < 0.05,^{△ △} p < 0.01);

: The difference between instant intervention group of primary school students and long-term intervention group was not statistically significant;

: The difference between instant intervention group of junior high students and long-term intervention group was not statistically significant (p > 0.05).

Those nutrition questions marked ‘a’ showed that the awareness of nutrition knowledge between the instant intervention group and long-term intervention group in primary school was not statistically significant. Those nutrition questions marked ‘b’ showed that the awareness of nutrition knowledge between the instant intervention group and long-term intervention group in junior high school was not statistically significant. However, the intervention group and control group in the baseline were high (p < 0.05).

A comparison of the average knowledge scores of nutrition between the intervention group and the control group is shown in Table 3.

Table 3.

Comparison of the average knowledge scores of nutrition among the intervention group and control group (x±s), China, 2011–2012.

Period	Group	Primary school students				Secondary school students				Total
		Boy		Girl		Boy		Girl		Total
		n	Scores	n	Scores	n	Scores	n	Scores	n	Scores
B	Int	142	8.86±3.02^a	131	8.69±2.60^b	126	8.91±2.56	116	9.75±2.67^{d ▼}	515	9.03±2.75^e
B	Con	132	8.85±3.07^a	137	9.09±3.49^b	141	9.94±3.62^c	133	9.70±2.60^d	543	9.40±3.25^e
I	Int	134	14.91±3.21^*	129	14.90±2.88^*	122	13.89±3.81^*	116	15.04±3.09^*	501	14.70±3.28^*
I	Con	123	9.89±3.42	132	10.05±2.95	138	10.59±3.03^c	129	10.60±2.87	522	10.29±3.08
L	Int	132	11.62±2.67^△	121	12.91±2.58^△	103	12.52±3.50^△	116	13.27±2.46^△	472	12.35±2.89^△

B: Baseline, I: Instant, L: Long-term, Int: intervention group, Con: control group;

The knowledge scores of both transverse and longitudinal groups were also compared using analysis of variance (any two groups compared with LSD method);

:In five longitudinal groups, the instant intervention group had the highest scores, and the difference was statistically significant (p < 0.01).

△

: In five transverse groups, the scores of the long-term intervention group were lower than the instant intervention group’s, but higher than the other three groups (p < 0.01).

a, b, c, d, e

: With five longitudinal groups, any two groups compared with LSD method, and the differences were not statistically significant (p > 0.05).

▼

: In 5 transverse baseline intervention groups, the secondary school girls group had the highest scores, and the difference was statistically significant (p < 0.05).

The nutrition knowledge scores were from mean 9.03, SD±2.75 points (before the intervention) to 14.70±3.28 points (immediately after the intervention), and the differences were statistically significant (t = 29.78, p < 0.01). There were statistically significant differences between before and after the intervention in primary boys, primary girls, junior boys, and junior girls (t = 16.15, p < 0.01; t = 18.29, p < 0.01; t = 12.05, p < 0.01; t = 13.97, p < 0.01, respectively). The increase in amplitude was highest for primary girls (6.20 points), ahead of primary boys (6.05 points), junior girls (5.29 points), and junior boys (4.98 points), respectively.

The nutrition knowledge score of the long-term intervention group was 12.35±2.89. It was lower than for the immediately after intervention group (t = 12.40, p < 0.01), but higher than baseline (t =18.04, p < 0.01) and control groups. Nutritional knowledge scores were different between the long-term intervention group and instant intervention group. The primary boys, primary girls, junior boys, and junior girls scored 3.29, 1.99, 1.36, and 1.77, respectively. Boys in primary school recorded the fastest decline in score than others. Most importantly, the difference was statistically significant (p < 0.01).

Diet and behavior habits

There were no statistically significant differences between baseline and control groups (p > 0.05) (Table 4).

Table 4.

Comparison of the eating habits between instant intervention and long-term intervention groups.

Question	Group	Option				χ²	p
Are you willing to change your picky eating habits from now on	InstantLong-term	Not picky	Yes	Try my best	No	14.09	<0.01^a
		115	250	98	34
		111	208	133	17
Are you willing to change your habit of eating high energy snacks from now on	InstantLong-term	Don’t eat	Yes	Try my best	No	18.10	<0.01^a
		64	169	179	80
		48	159	220	42
Are you willing to increase the frequency of eating breakfast from now on	InstantLong-term	Eat every day	Yes	Try my best	No	2.99	0.39
		256	114	44	83
		259	88	46	74
What is your first consideration on food choice	InstantLong-term	Taste	Nutritional value	Convenience	Multiple considerations	6.82	0.08
		46	401	19	20
		69	356	18	21

The difference between instant and long-term intervention group responses was statistically significant (p<0.01).

Knowledge of preference for certain foods and picky eating habits

Intervention can effectively alter the behavior of any preference for certain foods and picky eating habits. Before intervention, 382 participants had these bad habits. Then, after the intervention, 65.45% of students expressed the view that they would certainly change their habits and 25.65% would make every effort to change their habits. Nine months later, 23.23% students expressed the view that they would certainly change their habits and 37.15% would make every effort to change their habits. There were statistically significant differences between the immediately after intervention group and long-term intervention group in terms of having unhealthy food preferences and picky eating habits (χ² = 14.09, p < 0.05).

Knowledge of the intake of energy-dense snacks

Research has shown that increased energy intake is an important risk factor for obesity (21,22). Especially now, many primary and middle school students like to eat snacks, and they particularly like to eat some cookies or cakes. However, some studies have shown that a ‘habit’ of eating biscuits/cakes that is formed during childhood is likely to continue into adulthood (23,24). Before intervention, 428 participants had unhealthy food preferences and picky eating habits. Then, after the intervention, 39.48% students expressed the views that they would certainly change their habits and 41.82% would do their best to change their habits. Nine months later, 37.50% students expressed the view that they would certainly change their habits and 52.26% would make every effort to change their habits. There were statistically significant differences between the immediately after intervention group and long-term intervention group in the intake of energy-dense snacks (χ² = 18.10, p < 0.01).

The state of breakfast every day

Before intervention, 241 participants indicated that they did not eat breakfast every day. Then, after the intervention, 47.30% students expressed the view that they would certainly change their habits and 18.26% would do their best to change their habits. Nine months later, 42.30% students expressed the view that they would certainly change their habits and 22.16% would make every effort to change their habits. There were no statistically significant differences between the instantaneous and long-term intervention groups on eating breakfast every day (χ² = 2.99, p > 0.05).

Food safety concerns among primary and secondary school students

There is a need for broad-based food safety education among consumers, especially adolescents, who are food handlers of the future (25). The results of the study are as follows: out of 501 students, 417 students (83.28%) were going to focus more attention on food safety after immediate intervention; 374 (77.59%) of 482 students expressed the view that they would sharpen their focus on food safety in the future. There were no significant differences between the instant and nine months later intervention groups (χ² = 2.55, p > 0.05).

The views on food safety knowledge among primary and junior high school students are shown in Table 5.

Table 5.

Comparison of each knowledge point of food safety among students on pre-intervention and post-intervention (instant and long-term) (x±s).

Question	Int-group	Option				χ²	p
What’s the best measure taken on rotten vegetables and fruits?		Eat	Cook	Throw away	Don’t know
	Before^*	10	187	266	41
	Instant	13	172	270	23
	Long-term^*	24	175	246	22	15.33	0.02
Do you know the incident of Sanlu milk powder?		Know well	Know	A little	Don’t know
	Before^*△	74	176	109	141
	Instant^*▼	117	184	78	121
	Long-term^△▼	78	188	109	66	42.71	< 0.01
What’s your attitude to melamine?		Accept	Somewhat accept	Reject	Don’t know
	Before^*△	249	61	29	46
	Instant^*	276	67	19	21
	Long-term^△	284	63	16	19	22.85	< 0.01
What’s your attitude to vegetables after the Japanese nuclear leak?		Don’t eat	Eat less	Eat as usual	Don’t know
	Before	101	104	258	40
	Instant^▼	116	94	231	35
	Long-term^▼	89	74	273	27	13.30	0.04
What can guarantee the safety of your purchased food		Brand	Supermarket	Parents	QS logo
	Before^△	19	82	26	367
	Instant	16	64	22	355
	Long-term^△	25	64	9	361	11.88	0.07

1) Three groups compared with r by c Cochran–Mantel–Haenszel Statistics Test (CMH: choice General Association), p < 0.05;

2) Any two groups compared with chi-square test, ^*: before and instant intervention group had statistically significant differences (p < 0.05); ^△: before and long-term intervention groups had statistically significant (p < 0.05); ^▼: instant and long-term intervention group had statistically significant differences (p < 0.05).

There were significant differences in the views on ‘deterioration of fruit and vegetables means inedible’ and ‘the QS mark and food production date ensure that food is safe’ between the before and nine-month later intervention groups (χ² = 11.28, p < 0.05 and χ² = 10.07, p < 0.05, respectively). There were significant differences in the view of ‘whether you know the incident of Sanlu milk powder’ between before, immediately after, and nine months later intervention groups (p < 0.01). There were significant differences in the views on ‘the influence on vegetables of nuclear leak in Japan’ between immediately after and nine months later (χ² = 10.28, p < 0.05).

The knowledge scores on food safety among primary and secondary school students are shown in Table 6.

Table 6.

Comparison of the knowledge scores of food safety among intervention group and control group. (x±s).

Period	Group	Primary school students				Secondary school students				Total
		Boys		Girls		Boys		Girls		Total
		n	Scores	n	Scores	n	Scores	n	Scores	n	Scores
B	Int	142	11.35±3.86^*	126	12.19±3.54^{* ▼}	131	12.31±3.93^*▼a	116	12.60±3.21^*	515	12.08±3.69^*
B	Con	132	10.78±0.35^*▼	141	11.70±3.86^*	137	11.44±3.76^{a b}	133	12.87±3.32^*	543	11.70±3.81^*
I	Int	134	12.85±4.46^△	122	12.71±3.82△ ^▼	129	13.07±4.16△^▼	116	13.73±3.98^△	501	13.08±4.12
I	Con	123	9.93±3.62^▼	138	11.13±2.82	132	10.67±2.81^b	129	11.71±2.67	522	10.87±3.05
L	Int	132	13.34±3.95^△	121	12.93±3.79△	103	14.22±3.12^*△	116	13.77±3.78^△	472	13.58±3.69

1) B: Baseline, I: Instant, L: Long-term, Int: intervention group, Con: control group;

2) The knowledge scores of food safety using analysis of variance (any two groups compared with LSD method), only compared with longitudinal groups;

3) In five longitudinal groups, ^{* ▼ △ a b} express that the difference between the two groups was not statistically significant (p > 0.05).

The immediately after intervention group achieved higher scores than those of other groups (p < 0.01). There were significant differences between instant and nine months later intervention groups (t = 2.00, p < 0.05). There was no significant difference between different schools and different gender (p > 0.05). There were significant differences between before and instant primary boys and secondary girls (t = 2.99, p < 0.01 and t = 2.349, p < 0.01, respectively). The primary boys, primary girls, junior high boys, and junior high girls scored 1.50, 0.52, 0.76, and 1.13, respectively.

Discussion

The means of medical university-based nutrition education

At present, nutrition education in primary and secondary schools is deficient, which has led to primary and secondary school students’ lack of basic understanding of nutrition knowledge in China (9). Therefore, to help students develop lifelong healthy habits, more holistic health and nutrition curricula are needed that not only teach students health knowledge at the cognitive level but also improve the nutritional status of school-age children and adolescents. It is urgent for schools and related departments to enhance nutrition education in primary and secondary schools, and to explore various ways to improve the young generation’s nutrition KAP at the same time. Inclusion of nutritional education in primary and secondary school curricula is one effective way (10,14). To participate in the work of popular science, there is a tremendous need for more professionals to be devoted to it; the development of college students’ science associations and students’ science and technology organizations (9,11) is a reciprocal choice. Through these organizations, science and technology activities have started to enter into the school lives of primary and secondary school students in recent years. Many nutritional science research studies focus on theoretical topics and are restricted to the laboratory in China (4). Few of them pay much attention to popular science activities, even on nutrition and food hygiene in schools, and few evaluations on the effects immediately after and in the longer term have been conducted. This is the theme of our study, and the issue to which this study seeks to draw more attention. We encourage nutrition undergraduates to serve schools with their professional skills, including the development of nutrition education. This could provide opportunities for them to practice their professional theories in the real world and help them find their own goal at the same time.

Immediate and long-term effect evaluations were carried out to provide a theoretical basis for nutrition education involved in primary and secondary school education. The results prove that this intervention appeared to be effective and that it is worth exploring. Further school-based nutrition education efforts should focus on culturally and geographically appropriate, multicomponent approaches that actively involve family members, schools and teachers, community members, and health and nutrition experts (26). We also recommend that nutrition-information interventions can be more effective when using nutrition information that is generally liked by the target population in combination with an educational intervention to increase objective nutrition knowledge. We can use active learning strategies include simulations and learning games, teacher and peer modeling, role-playing, and so on.

The effectiveness of medical college-based nutrition education for primary and junior high school students’ nutrition KAP

In this study, the scores illustrated that knowledge of nutrition and food safety among primary and junior high school students was seriously lacking, which was similar to the findings of other reports (17,27 –29). Nevertheless, after this intervention, the awareness scores of nutrition and food safety knowledge were higher than before, and effectiveness continued to nine months later, which was similar to the results of other reports (30 –36). Especially, the awareness of ‘the association between microelements and disease’ (18,33), ‘Chinese food guide pagoda’, ‘spoiled food’, and ‘the problem of hot food’ was significantly different before and after the interventions. In addition, the majority of the students under intervention indicated that they would pay more attention to food, but no difference was found in the control group.

To some extent, through the contrast before and after intervention, the nutrition and food safety information acquired in this education program indicates that the students’ knowledge of nutrition has improved. All the things we have mentioned demonstrate that this program was effective, feasible, and worthy of being popularized.

The effectiveness of medical university-based nutrition education interventions for changing eating behavior among primary and junior high school students

Healthy eating in childhood and adolescence is important for proper growth and development and can prevent health problems such as obesity, dental caries, iron deficiency, and osteoporosis (37,38). It is generally known that health promotion is a transformation process of knowledge, attitude, and behavior (11 –13,20,27). The awareness of nutrition plays a vital role in shaping healthy eating behavior; meanwhile, the change of attitude is the principal element to lead to changing behavior (9). Thus, besides enhancing the awareness of nutrition and food safety among primary and junior high students, healthy eating behavior is also important. A study has shown that dietary intentions and planning are assumed to be primary predictors of dietary changes (39). Most health behavior models share the assumption that the intention to change is a predictor of actual behavior (40,41). Based on the results of this investigation, the majority of the school students were willing to change their bad eating behaviors after intervention, such as picking food, eating junk food, and not having breakfast every day, which was similar to the results of earlier reports (9,18,31,34 –39).

However, the change of attitude was not significantly different nine months later, which may be due to lack of continuous intervention. Moreover, this result may demonstrate that the effect of this intervention is limited on the change of attitude, and more effective intervention will be needed in the future. In addition, changes in behavior also need to be evaluated in further research. Food choice patterns established during youth will likely influence long-term behaviors (42). The use of food safety information when people select food products should decrease food risk as well as consumers’ concerns when selecting food.

The future of medical college-based nutrition education interventions

Compared with the control group, the intervention was impactful. The study shows that nutritional knowledge scores were different between long-term and instant intervention groups. Schools have an important role to play in equipping children with the knowledge, attitudes, and skills they need in order to protect their health. Young persons need nutrition education to assist them to develop lifelong eating patterns consistent with the Dietary Guidelines for Chinese Food Guide Pyramid. This was the first time that we were able to cooperate with the students’ association and organizations of a medical college, and implement the program via a medical college-based nutrition education method for primary and secondly school students.

College students, especially medical university students, should take more responsibility for nutrition and health knowledge communication and popularization. Meanwhile, we have built a long-term cooperation mechanism with primary and secondary schools on nutrition education. Comparison of the difference between long-term and immediate intervention groups revealed the need to constantly develop nutrition knowledge by strengthening the consciousness of students, otherwise they will gradually forget.

Daily consumption of breakfast

In recent years, many primary and middle school students in China often do not eat breakfast for reasons such as lack of time or parents who are busy working. Although some are eating breakfast, energy intake is inadequate and quality is poor. Several studies have reported that breakfast consumption is linked to some aspects of brain function, such as neural network activity and cognitive performance (43,44). Studies have shown that regularly skipping breakfast is closely linked to increased rates of obesity in all age groups (45 –49). Our research shows that the length of the intervention time has not affected the effect of the interventions on breakfast. Increasing frequency of breakfast was positively correlated with students’ performance in both male and female healthy adolescents (4).

Limitations

There are several limitations to this study. Firstly, the time for the program was short; students only engaged in one activity as a result of limited time and material resources. There was no control group at nine months follows up. Other changes might have occurred in the schools during the nine month period that affected children’s knowledge, but there was no way of seeing this. If there were sufficient time to organize more activities, the effect of intervention may be better. Secondly, we only selected one primary school and one middle school and random selection was not done. Extrapolation to other schools’ students remains to be further validated. Furthermore, the effect of this intervention is limited to the change of attitude; eating habits were self-reported rather than measured in a more objective way. Nevertheless, this intervention trial could be easily reproduced in other regions. Course topics and the content of the nutrition lecture can be applied to other places. In the future, different areas can replicate the intervention trial, in order to have a better study about the influence factors of the intervention effect. More effective intervention will be needed in the future.

Conclusions

School-based nutrition and food safety education intervention resulted in a significant impact on students’ nutrition knowledge. The present study found that the nutrition and food safety education program were beneficial and effective for primary and junior high school students. This program seemed to be applicable, feasible, and is worth exploring further.

Footnotes

Acknowledgements

The authors thank the project sponsors, the China Association for Science and Technology Graduate science research capability class project for providing college graduate project funding and technical guidance. Thanks also to Hua-Ping Wang, Jing-Qiu Wang, Kun Li, Zhi-Jiao Zhang, Huan Zeng, Hong Wang, Yong Zhang, and Tao Gong in Chongqing Medical University for their active participation. Thanks to Professor Jianfei Guo in University of Cincinnati for the language polishing.

Conflict of interest

The authors declare no conflict of interests.

Funding

This research received funding from the China Association for Science and Technology through its graduate student scientific research project funds.

Contibutorship statement

All authors contributed to the design of the study. Wen-Jie Zhou and Xiang-long Xu were responsible for literature searches, the interpretation of the results, and writing the manuscript. Ge Li, Xiang-Long Xu, Ya-Ling Qie, and Yong Zhao participated in the development of the study protocol, data collection, and analysis. Yong Zhao, Ge Li, and Manoj Sharma contributed to the drafting of the manuscript. Yong Zhao was responsible for the conception of the study and overall supervision of the data collection and analysis, the interpretation of the results, and manuscript preparation. All authors have read and approved of the final manuscript.

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