The Effectiveness of Nutritional Interventions Based on Health Education and Promotion Theories and Models: A Systematic Review
Jeyran Ostovarfar; PhD ¹, Somayeh Zare; PhD¹, Mohammad Hossein Kaveh; PhD^*1,
Maral Ostovarfar; MA^{2, 3}, Fatemeh Eftekharian; MA¹ & Mouhebat Vali; MSc¹

¹ Department of Health Promotion, Shiraz University of Medical Sciences, School of Health and Nutrition, Shiraz, Iran.
² School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
³ Yazd Research and Clinical Centre for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
 

 
Introduction

Nutrition is an important factor in providing health and developing illness. People's nutrition status determines the health condition of society (Coffey et al., 2018). Food patterns are different among various people with diverse sorts of socioeconomic statuses, races, communities, and cultures. Meanwhile, the socio-economic development of every society is associated directly with people's nutrition status (Jessri et al., 2011). Poor nutrition pattern not only causes overweight and obesity, but also is the cornerstone of other chronic diseases such as cardiovascular discuses. The family's preferences for food items are unacceptable if poor nutritional meals are consumed instead of rich ones (Alkerwi et al., 2015). Nowadays, educational sciences derived from educational theories have important roles in changing the knowledge, behavior, and habits of people. Nutrition education content and process of behavioral change should be provided based on the principles of education for achieving behavioral goals (Miller and Cassady, 2015).
The analysis of food patterns is a guideline in providing practically nutritional recommendations because presenting these recommendations for people in the form of food patterns is more comprehensible rather than presenting the role of nutritional materials (Djazayery et al., 2008). These patterns include a wide range of consumer's behaviors related to food materials such as their current intake amount and type, cooking method, serving, and wastes. A food basket is a pattern consisting of sufficient amount of energy and essential minerals and other ingredients, so that its combination would be balanced to provide the necessary energy for doing daily activities and increase body resistance against diseases (Asghari et al., 2012). Besides, sufficient food pattern is based on the principles including balance, nutritional needs, protection of peoples' health, individual differences, habits, food preferences, nutritional literacy, knowledge, distribution of facilities, and enough economic and physical access at the national level (Pelletier, 2015).
The aims of providing suitable basket include:

Nutrition education can be very effective in modifying inappropriate nutritional behaviors and enhancing peoples' knowledge. Different investigations confirmed the impact of nutrition training over nutritional performance of families (Friel et al., 1999, Pei-Lin, 2004, Shariff et al., 2008). Moreover, the value of educational programs depends on their effectiveness, which is, subsequently, associated with using theories and models efficiently.
Regarding the role of healthy nutrition in preventing and controlling contagious diseases, this study was conducted to investigate the effectiveness of interventions, the range of nutrition patterns change in the studied populations after intervention, find the best theories, reasons, and ways of implementing the interventions.
Materials and Methods
The PubMed, Science Direct, Scopus, and Cochrane databases were searched using the keywords “nutrition behavior” or “food behavior” or “dietary behavior” and “model” or “theory” and “intervention” or “predict” without any time limitation in February 2018. The articles published from 2013 to 2017 were studied. Retrospective cohort, prospective, case-control, cross-sectional, qualitative studies, protocols, as well as investigations using electronic tools for performing the intervention were removed from the present study. Theory-based interventions conducted in a specific duration of time were selected for this investigation. Relevance of the studies' subject to the main aim was confirmed in three stages including reviewing the title, the abstract, and the main text of the articles. As a result, 3090 articles were primarily monitored. Followed by removing the 558 repeated papers, a total of 153 articles were studied, among which 182 of them were review articles and 1969 papers were not related to the main subject of the present study. Consequently, 219 articles remained, of 78, 28, and 14 articles were cross-sectional, qualitative, and protocol, respectively. Of the investigated studies, 71 papers were not theoretically oriented, which resulted in the final number of 28 articles. Followed by investigating the main texts of the studies, we found that one paper was a review study, one paper was a part of another study, and the last one was a cross-sectional investigation, which were omitted. The other 25 articles were included in the study. The screening process, exclusion, and final selection of articles are shown in figure 1. 
Results
Regarding the included studies, eight models or theories were used in the interventions. Respectively, 4, 1, 1, 1, 1, 2, 5, and 9 studies
were conducted based on Social Cognitive Theory, Empowerment model, Social-Ecological Theoretical Framework, BASINEF model, PENDER Health Promotion, Self-determination theory, Theory of Planned Behavior, and Health Belief Model. The details and results of these studies are presented in Table 1 to find the most qualified studies.
Social cognitive theory: Four studies conducted their nutritional interventions based on the social cognitive theory (Healthy Hidayanty et al., 2016, Ko et al., 2016, Mead et al., 2013, Najimi and Ghaffari, 2013). Two studies were carried out among adults, of which one article studied obese individuals (Ko et al., 2016, Mead et al., 2013). The other two studies were on students and adolescents (Healthy Hidayanty et al., 2016, Najimi and Ghaffari, 2013). In one of the mentioned interventions, parents and teachers of the students were also involved (Najimi and Ghaffari, 2013). In another intervention, students' parents received a weekly nutrition education booklet (Healthy Hidayanty et al., 2016). One of the four studies combined social cognitive theory with the social ecological model (Mead et al., 2013).
In designing interventions, self-efficacy was considered in all studies (Healthy Hidayanty et al., 2016, Ko et al., 2016, Mead et al., 2013, Najimi and Ghaffari, 2013). Three studies considered observational learning and outcome expectation as effective constructs in interventions to improve the participants' nutrition (Healthy Hidayanty et al., 2016, Ko et al., 2016, Najimi and Ghaffari, 2013). Furthermore, the ability to behave was another component considered in three of the four included studies (Ko et al., 2016, Mead et al., 2013, Najimi and Ghaffari, 2013). Environmental factors in two studies (Healthy Hidayanty et al., 2016, Ko et al., 2016), stress control in one study (Najimi and Ghaffari, 2013) and self-regulation in one study (Healthy Hidayanty et al., 2016) were considered as effective constructs.
Mead et al. conducted a study  based on the ecological social model, used mass media such as television, radio, and extensive social activities in health centers, schools, and so on (Mead et al., 2013). The other three studies used training sessions in various forms such as lectures, group discussions, goal setting with the help of participants for training. They also used booklets and training booklets as educational assistance (Healthy Hidayanty et al., 2016, Ko et al., 2016, Najimi and Ghaffari, 2013).
Empowerment model: The aim of this study was to determine the effect of education on obese or overweight women's abilities to modify their eating behaviors. The study was conducted in four continuous phases that included threat perception, problem solving, participatory education and evaluation. To remind all the topics discussed in the training sessions, participants were provided with a booklet. The constructs used in the study were knowledge, attitude, self-esteem, and self-efficacy (Mataji Amirrood et al., 2013).
 Social ecological theoretical frame work: This study was conducted among females in 11 different communities, based on Social Ecological Theoretical Framework. The aim was investigated the effect of intention on nutritional diet program. The program focused on knowledge, attitudes, self-efficacy constructs as well as problem-solving skills. Training sessions were devoted to lectures and practices to develop skills related to food planning, food shopping, reading food labels, and ways to buy nuts (Summers and Klassen, 2013).
 BASNEF model: The study was conducted on female students in which the parents of the participants were also present to further influence the intervention in the study. In order to empower healthy eating behaviors, 2 sessions were held for students by lecture method and one session was held for the students' parents by instructional method. A textbook was also administered as a teaching aid for students. The constructs of interest included belief, attitude, abstract norm, empowerment factors, dietary intention, and behavior (Pirzadeh et al., 2014).
 Pender's health promotion model: One study used this model to improve people's nutritional behavior. The constructs considered in the study were perceived benefits, perceived barriers, perceived self-efficacy, commitment to action, interpersonal and situational effects, as well as nutritional behavior. The training was conducted through lectures, questions - answers, and group discussions. Training guide for healthy eating behaviors was also used as an educational assistance (Khodaveisi et al., 2017).
Self-determination theory: Two studies were conducted using self-determination theory with the aim of improving nutritional status (Girelli and Luccidi, 2016, Leblanc et al., 2015). One study was conducted on students with the help of local teachers and volunteers (Girelli and Luccidi, 2016). Another study was also conducted over women and men aged 25 to 50 years to improve their knowledge about a Mediterranean diet (Leblanc et al., 2015). Motivation and attitude constructs were considered as effective constructs in both studies (Girelli and Luccidi, 2016, Leblanc et al., 2015). In one study, the intervention consisted of three group sessions with four telephone calls and a recorded diet (Leblanc et al., 2015). The other study consisted of at least two hours of training per week by local teachers and volunteers during the school period (Girelli and Luccidi, 2016).
Theory of planned behavior: Five studies used the theory of planned behavior; two  were conducted on students (Maleki et al., 2016, Taghdis et al., 2016), one of which was on female students with type 2 diabetes (Maleki et al., 2016). One study among adults aimed at reducing the consumption of sugary drinks and the other intervention was aimed to change the amount of physical activity (MoveMore) (Zoellner et al., 2016). There was also a study on athletes' coaches to improve the accuracy of their nutritional recommendations (Jacob et al., 2016), and finally a study was conducted  on the chefs of child care centers (Yoong et al., 2015).
All five studies used all constructs of the theory of planned behavior (behavior, intention, subjective norms, and perceived behavioral control) (Jacob et al., 2016, Maleki et al., 2016, Taghdis et al., 2016, Yoong et al., 2015, Zoellner et al., 2016).
In three studies, lecture sessions with discussion were used for teaching, while in one study, educators and parents were trained to improve abstract norms in students (Jacob et al., 2016, Maleki et al., 2016, Taghdis et al., 2016). One of the studies, in addition to teaching through lectures, expressed the scenario based on the problem-solving plan (Maleki et al., 2016). One study emailed food menu instructions to the child care centers, along with a training booklet including specific behaviors to chefs based on the theory of programmed behavior (Yoong et al., 2015). Finally, a study taught nutrition to students through phone calls and voice messages (Zoellner et al., 2016).
Health belief model: The results showed that nine studies had performed their nutritional interventions based on the health belief model. Among these, two studies were conducted on students (Ghaderi et al., 2017, Shafiei et al., 2017) and two were performed over older women (Iranagh et al., 2018, Iranagh et al., 2016). Two studies were carried out on young people (Evenson and Sanders, 2016, Tavakoli et al., 2016), one of whom was among medical students (Tavakoli et al., 2016). One study investigated pregnant women (Khoramabadi et al., 2016), one study was conducted on adult women (Shobeiri et al., 2016), and finally a nutritional study was carried out on hospitalized cardiovascular patients (Shojaei et al., 2016).
All nine studies considered knowledge constructs, perceived sensitivity, perceived intensity, perceived benefits, and perceived barriers (Evenson and Sanders, 2016, Ghaderi et al., 2017, Iranagh et al., 2018, Iranagh et al., 2016, Khoramabadi et al., 2016, Shafiei et al., 2017, Shobeiri et al., 2016, Shojaei et al., 2016, Tavakoli et al., 2016). In addition to the mentioned constructs, six studies used the self-efficacy construct (Evenson and Sanders, 2016, Ghaderi et al., 2017, Iranagh et al., 2018, Iranagh et al., 2016, Shafiei et al., 2017, Tavakoli et al., 2016) and one of the studies used the cues to action construct (Ghaderi et al., 2017).
Eight studies used the lecture method (Evenson and Sanders, 2016, Ghaderi et al., 2017, Iranagh et al., 2018, Iranagh et al., 2016, Khoramabadi et al., 2016, Shafiei et al., 2017, Shobeiri et al., 2016, Tavakoli et al., 2016). Six studies used asking and answering method sessions to increase awareness and motivation (Ghaderi et al., 2017, Iranagh et al., 2018, Khoramabadi et al., 2016, Shafiei et al., 2017, Shobeiri et al., 2016, Tavakoli et al., 2016). In four studies, group discussion was one of the teaching methods

(Ghaderi et al., 2017, Iranagh et al., 2018, Khoramabadi et al., 2016, Shobeiri et al., 2016). The method of brainstorming was also seen as an educational method in two studies (Ghaderi et al., 2017, Tavakoli et al., 2016). Dr. Shojaei et al. considered face-to-face training to increase patients' knowledge (Shojaei et al., 2016). In addition to lecturing, Evenson et al. also used practical demonstrations to improve the inhibitory behaviors of osteoporosis, which included adequate calcium intake, vitamin D, and exercise (Evenson and Sanders, 2016). Finally, five studies used educational assistance such as booklets, pamphlets, photos, and posters (Iranagh et al., 2018, Iranagh et al., 2016, Khoramabadi et al., 2016, Shafiei et al., 2017, Shojaei et al., 2016).
Protection – motivation theory (PTM): One study used protective-motivational theory on individuals over 60 years of age. In this study, the constructs of knowledge, attitude, protective-motivational behaviors, perceived fear, and perceived intensity were evaluated and intervened. In this study, lecturing, brainstorming, and discussion methods were also used to educate the elderly (Rouhi Afkari 2016).