Psychosocial predictors of eating habits among adults in their mid-30s: The Oslo Youth Study follow-up 1991–1999

Background  

The predictive value of the psychosocial constructs of Theory of Planned Behaviour (TPB) on subsequent dietary habits has not been previously investigated in a multivariate approach that includes demographic factors and past dietary behaviour among adults. The aim of this study was to investigate to what extent TPB constructs, including intention, attitudes, subjective norms, perceived behavioural control, and perceived social norms, measured at age 25 predicted four eating behaviours (intake of fruits and vegetables, whole grains, total fat and added sugar) eight years later.     

Applying the theory of planned behavior to predict dairy product consumption by older adults

Objective: The purpose of this study was to explain intention to consume dairy products and consumption of dairy products by older adults using the Theory of Planned Behavior (TPB). The factors examined were attitudes, subjective norms, and perceived behavioral control.

Design: A cross-sectional questionnaire was administered.

Setting: Community centers with congregate dining programs, group classes, and recreational events for older adults.

Subjects: One hundred and sixty-two older adults (mean age 75 years) completed the questionnaire. Subjects were mostly women (76%) and white (65%), with about half having less than a high school education or completing high school.

Variables Measured: Variables based on the TPB were assessed through questionnaire items that were constructed to form scales measuring attitudes, subjective norms, perceived behavioral control, and intention to consume dairy products. Dairy product consumption was measured using a food frequency questionnaire.

Analysis: Regression analyses were used to determine the association between the scales for the 3 variables proposed in the TPB and intention to consume and consumption of dairy products; the level was set at .05 to determine the statistical significance of results.

Results: Attitudes toward eating dairy products and perceived behavioral control contributed to the model for predicting intention, whereas subjective norms did not. Attitudes toward eating dairy products were slightly more important than perceived behavioral control in predicting intention. In turn, intention was strongly related to dairy product consumption, and perceived behavioral control was independently associated with dairy product consumption.

Conclusions and Implications: These results suggest the utility of the TPB in explaining dairy product consumption for older adults. Nutrition education should focus on improving attitudes and removing barriers to consumption of dairy products for older adults.     

The role of ethnic identity and perceived ethnic norms in the purchase of ethnical food products

The role of group and individual variables in the purchasing of ethnical food products was tested through an extended theory of planned behavior (TPB) model. A total of 100 Indian female immigrants, living in Rome, Italy, were administered a self-reported questionnaire measuring the classical TPB variables (attitudes, subjective norms, perceived behavioral control, behavioral intentions and self-reported behaviors) plus 3 additional variables: identification with the Indian ethnic group, perceived norms of the Indian ethnic group, and past behavior. Results confirmed that the new variables introduced are distinct from the original TPB components. As expected, variables at both the individual and group level play a role in predicting purchasing of ethnical foods products. Hierarchical multiple regressions showed that past behavior, ethnical identification, and perceived group norms explain an additional proportion of variance in intentions and self-reported behaviors, independently of attitudes, subjective norms and perceived control. A significant 2-way interaction between ethnical identification and perceived group norms was also detected: as predicted, the highest levels of ethnical food purchasing behavior were reported by high ethnical identifiers with stronger ethnical group norms, while the lowest levels were reported by low ethnical identifiers with weaker ethnical group norms. Theoretical and practical implications of results are discussed.     

Applying theory of planned behavior to fruit and vegetable consumption of young adolescents

PURPOSE: The purpose of this research was to investigate how well Theory of Planned Behavior (TPB) predicted frequency of consumption of fruits and vegetables among seventh graders and to investigate whether gender or socioeconomic status (SES) had moderating effects on the relationships between the constructs in the model. DESIGN: Two identical self-administered paper and pencil surveys were distributed 6 months apart. Path analyses of the TPB models by gender and SES were performed with AMOS software. SETTING: The study occurred in eight middle schools from school districts in the Minneapolis--St.Paul metropolitan area, where a minimum of 20% of the students qualified for free or reduced-price meals. SUBJECTS: Of the invited seventh graders, 1406 (74%) completed data for the model constructs at baseline and for behavior at interim data collection. MEASURES: We assessed frequency of consumption of fruits and vegetables and attitudes, subjective norms, barriers, and intentions related to this behavior. Three levels of SES were created based on questions about free lunch, parents' education, and work. RESULTS: No significant direct effects of attitudes and subjective norms on behavior were found, but for barriers, both indirect effects through intentions and direct effects on behavior were significant. Seven percent of the variation in the frequency of fruit and vegetable consumption and 31% of the variation in intention to eat more fruits and vegetables were explained by the model. Gender appeared to have moderating effects on the relationships between attitudes and intention and between intentions and behavior in the model. There were no moderator effects of SES, but the larger dropout rates from the low-SES group could have caused the groups to become more homogeneous. CONCLUSION: The data fit the model well; still, large proportions of the variance in the frequency of consumption of fruits and vegetables were unexplained. This may be related to the operationalization of the model constructs or to missing important factors in the model. Furthermore, there appeared to be strong relationships between subjective norms or barriers and intentions as well as gender differences in the strengths of the relationships in the model that may have implications for intervention methods or messages.     

Modeling tanning salon behavioral tendencies using appearance motivation, self-monitoring and the theory of planned behavior

The constructs of appearance motivation and self-monitoring were added to the Theory of Planned Behavior in the prediction of tanning salon use in young people. The variables of the Theory of Planned Behavior proved effective at predicting tanning salon behavioral intentions and tendencies. Intentions and perceived behavioral control predicted tanning salon behavioral tendencies, while attitudes, subjective norms and perceived behavioral control predicted tanning salon behavioral intentions. Appearance motivation did not show any direct or interaction effects in the prediction of tanning salon behavioral intentions. It did, however, prove superior to health orientation in the prediction of tanning salon attitudes. Self-monitoring interacted with subjective norms in the prediction of tanning salon intentions, with high self-monitors showing stronger subjective norm-intention relationships than low self-monitors. These results imply that appearance-related interventions could prove efficacious in reducing young people's tanning salon behavioral tendencies. Furthermore, it may be important to consider individual's self-monitoring status when targeting skin cancer prevention information to young people.     

Predicting pediatricians' communication with parents about the human papillomavirus (hpv) vaccine: an application of the theory of reasoned action

This study examines the ability of the theory of reasoned action (TRA) and the theory of planned behavior (TPB) to predict whether or not pediatricians encourage parents to get their adolescent daughters vaccinated against the human papillomavirus (HPV). Four-hundred and six pediatricians completed a mail survey measuring attitudes, subjective norms, perceived behavioral control, intentions, and behavior. Results indicate that pediatricians have positive attitudes, subjective norms, and perceived behavioral control toward encouraging parents to get their daughters vaccinated, that they intend to regularly encourage parents to get their daughters vaccinated against HPV in the next 30 days, and that they had regularly encouraged parents to get their daughters vaccinated against HPV in the past 30 days (behavior). Though the data were consistent with both the TRA and TPB models, results indicate that perceived behavioral control adds only slightly to the overall predictive power of the TRA, suggesting that attitudes and norms may be more important targets for interventions dealing with this topic and audience. No gender differences were observed for any of the individual variables or the overall fit of either model. These findings have important theoretical and practical implications for the development of health communication messages targeting health care providers in general, and for those designed to influence pediatricians' communication with parents regarding the HPV vaccine in particular.     

Psychosocial correlates of physical activity in white and African-American girls.

PURPOSE: To evaluate the relative utility of the Theory of Reasoned Action (TRA) and the Theory of Planned Behavior (TPB) in explaining intentions and physical activity behavior in white and African-American eighth-grade girls. METHODS: One-thousand-thirty white and 1.114 African-American eighth-grade girls (mean age 13.6 +/- 0.7 years) from 31 middle schools in South Carolina completed a 3-day physical activity recall and a questionnaire assessing attitudes, subjective norms, perceived behavioral control, self-efficacy, and intentions related to regular participation in moderate-to-vigorous physical activity (MVPA). RESULTS: Among Whites, 17% of the variance in intentions was contributed by subjective norms and attitude, with intentions accounting for 8% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 40% and 10% of the variance, respectively. Among African-Americans, subjective norms and attitude accounted for 13% of the variance in intentions, with intentions accounting for only 3% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 28% and 5% of the variance, respectively. CONCLUSIONS: The results provided limited empirical support for the TPB among white adolescent girls; however, our findings suggest that the planned behavior framework has limited utility among African-American adolescent girls. The relatively weak link between intentions and MVPA observed in both population groups suggest that constructs external to the TPB may be more important mediators of physical activity behavior in adolescent girls.     

Breastfeeding Duration and the Theory of Planned Behavior and Breastfeeding Self-Efficacy Framework: A Systematic Review of Observational Studies

Introduction Numerous studies have shown that the constructs of the Theory of Reasoned Action (TRA), Theory of Planned Behavior (TPB) and Breastfeeding Self-Efficacy (BSE) Framework can effectively identify relationships between maternal psychosocial factors and breastfeeding initiation. However, the ability of these theories to predict breastfeeding duration has not been adequately analyzed. The aim of the review was to examine the utility of the constructs of TRA/TPB and BSE to predict breastfeeding duration. Methods We conducted a literature search using Pubmed (1980-May 2015), Medline (1966-May 2015), CINAHL (1980-May 2015), EMBASE (1980-May 2015) and PsycINFO (1980-May 2015). We selected studies that were observational studies without randomization or blinding, using TRA, TPB or BSE as the framework for analysis. Only studies reporting on breastfeeding duration were included. Results Thirty studies were selected, which include four using TRA, 10 using TPB, 15 using BSE and one using a combination of TPB and BSE. Maternal intention and breastfeeding self-efficacy were found to be important predictors of breastfeeding duration. Inconsistent findings were found in assessing the relationship between maternal attitudes, subjective norms, perceived behavior control and breastfeeding duration. Discussion The inadequacy of these constructs in explaining breastfeeding duration indicates a need to further explore the role of maternal self-determination in breastfeeding behavior.     

Using the theory of planned behavior to predict two types of snack food consumption among Midwestern upper elementary children: implications for practice

This study examined the extent to which constructs of the theory of planned behavior (TPB) can predict the consumption of two types of snack foods among elementary school children. A 15-item instrument tested for validity and reliability measuring TPB constructs was developed and administered to 167 children. Snack foods were evaluated using a modified 24-hour recall method. On average, children consumed 302 calories from snack foods per day. Stepwise multiple regression found that attitudes, subjective norms, and perceived control accounted for 44.7% of the variance for intentions. Concurrently, intentions accounted for 11.3% of the variance for calorically-dense snack food consumption and 8.9% of the variance for fruit and vegetable snack consumption. Results suggest that the theory of planned behavior is an efficacious theory for these two behaviors. Future interventions should consider using this theoretical framework and aim to enhance children's attitudes, perceived control, and subjective norms towards snack food consumption.     

Drinking and Swimming: Investigating Young Australian Males’ Intentions to Engage in Recreational Swimming While Under the Influence of Alcohol

Drowning, a largely preventable problem, continues to be a serious issue worldwide, with young men particularly at risk. Alcohol and drugs are often present among young males and, particularly for males aged 18–34 years, alcohol is considered to be a significant risk factor for drowning. The current study aimed to understand the motivations guiding the intentions of young Australian men to engage in drinking and swimming, a behaviour not yet examined systematically. A cross-sectional correlational design was adopted to investigate the ability of the theory of planned behaviour (TPB) and additional variables to predict males’ intentions to drink and swim. Males (N = 211) aged 18–34 years (Mage = 23.93, SD = 4.01) completed a survey either on-line or paper-based. The survey assessed the TPB constructs of attitude, subjective norm, and perceived behavioural control (PBC); and additional variables of group norms, anticipated regret, objective (i.e. swimming ability) and perceived (i.e. perceived severity and perceived susceptibility) risk perceptions, and past behaviour. Support was found for the TPB constructs of attitude and subjective norm, but not PBC, as well as the additional constructs of group norm, anticipated regret, objective risk, and past behaviour in predicting males’ intentions to drink and swim; explaining an overall 76 % of variance. Knowledge gained from this study will help to inform resultant interventions designed to discourage alcohol use in, on, or around water and, thus, prevent drownings in this at risk group.     

Gender differences in the prediction of condom use among incarcerated juvenile offenders: testing the information-motivation-behavior skills (IMB) model

PurposeTo validate the predictive value of the Information-Motivation-Behavioral Skills (IMB) model of human immunodeficiency virus (HIV) prevention for sexually active juvenile offenders and to explore gender differences in IMB model constructs for condom-protected vaginal intercourse.MethodsSelf-report measures of acquired immune deficiency syndrome (AIDS) knowledge, pro-condom peer influence, risk perception, condom attitudes, condom use self-efficacy, frequency of vaginal intercourse, and frequency condom-protected vaginal intercourse were collected from predominantly African-American adolescent detainees. Analysis consisted of structural equation models for the combined sample (N = 523) and for separate gender groups (328 males and 195 females).ResultsIn the combined model, condom use was significantly predicted by male gender, peer influence, positive condom attitudes, and condom self-efficacy. In separate gender analyses, condom use among adolescent males was predicted by peer influence (modestly) and by positive condom attitudes, whereas condom use among females was predicted by peer influence, self-efficacy, and condom attitudes. Compared with males, females reported significantly greater knowledge, less peer influence, higher perceived risk for infection, more positive condom attitudes, and more self-efficacy, but they reported less condom use.ConclusionsFemales may find it difficult to use condoms consistently despite their awareness of their efficacy. Power imbalances or other dynamics operating in their relationships with males need further exploration. Gender differences in the relationship between condom self-efficacy and condom use were masked in the analysis of the total sample, indicating the value of testing theories of HIV prevention separately by gender.     

Predicting physical activity intention and behaviour among children in a longitudinal sample

We examined predictors of leisure-time physical activity intention and behaviour in children, and the potential direct and moderating effects of gender and ethnicity. Participants were 364 (230 Asian; 134 Caucasian) 9-11-year-old children who completed measures of the theory of planned behaviour (TPB) and physical activity behaviour (Physical Activity Questionnaire for Children) across three, 3-month intervals (i.e., two prediction time-periods) in Canada. The TPB explained 35-50% of the variance in physical activity behaviour and 74-76% of the variance in intention using structural equation modelling. An autoregressive longitudinal path model showed that the TPB predicted changes in physical activity and physical activity predicted changes in TPB constructs (p<.05). Overall, intention and perceived behavioural control were significant (p<.05) contributors to the direct prediction of behaviour and subjective norm and perceived behavioural control were significant (p<.05) predictors of intention. Gender did not show a robust relationship with physical activity or intention, but the effect of ethnicity on physical activity was mediated through perceived behavioural control (Asians less active than Caucasians). Finally, gender and ethnicity did not moderate TPB and physical activity relations (p<.05). These data suggest that childhood may be a formative stage for the development of physical activity cognitions and that promoting physical activity in children may require normative and control-based intervention.     

运用计划行为理论探讨高血压患者遵医服药行为的影响因素

目的运用计划行为理论,来探索社区中老年高血压患者遵医服药行为和行为意向的主要影响因素。方法按计划行为理论设计问卷,对武汉市社区卫生服务中心的中老年高血压患者进行调查,用结构方程分析理论各维度对遵医服药行为和行为意向的影响。结果行为态度、主观规范、知觉行为控制对于行为意向的直接影响分别为0.42,0.27和0.28,知觉行为控制、行为意向对于遵医服药行为的直接影响分别为0.59和0.27,整个计划行为理论对遵医服药行为的确定系数(R2)为0.52。结论行为态度是影响高血压患者遵医服药行为意向的主要因素,知觉行为控制则是影响遵医服药行为的最重要因素。     

Predicting adolescent pedestrians' road-crossing intentions: an application and extension of the Theory of Planned Behaviour

The present paper reports an application of the Theory of Planned Behaviour (TPB) to the prediction of road-crossing intentions among adolescents. In addition, the sufficiency of the TPB was assessed by examining the additional predictive utility of moral norms, anticipated affect and self-identity. A sample of 1833 adolescents completed a questionnaire containing a scenario depicting a potentially hazardous road-crossing behaviour, followed by items measuring the TPB constructs, moral norms, anticipated affect and self-identity. Regression analyses revealed that the TPB was able to explain 25% of the variance in road-crossing intentions, over and above the influence of age and gender, with perceived behavioural control emerging as the strongest predictor. The additional variables were found to increase the predictive utility of the TPB. The results have a number of theoretical and practical implications. In particular, interventions should focus on perceptions of control in order to encourage safer road-crossing behaviour among adolescents.     

Perceived norms for thinness and muscularity among college students: what do men and women really want?

Background

Perceived norms are related to health-related attitudes and behaviors, including body image. The current study examined body dissatisfaction and perceived norms for thinness and muscularity among male and female college students.

Method

Participants included 842 undergraduate students (64.5% female) who completed an online survey assessing body image and other health-related attitudes and behaviors. A series of independent sample and paired sample t tests were conducted to document sex differences in body dissatisfaction and misperceptions of thinness and muscularity norms.

Results

Based on pictorial ratings, both males and females reported discrepancies between their ideal and actual figures. Females perceived other females as significantly thinner and less muscular than the actual norms. Males perceived other males as significantly heavier than their own figures, but the difference between men's self-reported muscularity and perceived norm was not significant. Both males and females misperceived opposite-sex attractiveness norms for thinness and muscularity.

Discussion

Results suggest the importance of evaluating same-sex and opposite-sex perceived norms of thinness and muscularity in the etiology of body dissatisfaction, and this research informs social norms interventions targeting misperceptions of body image norms among both males and females.     

Pathways from Parental Knowledge and Warmth to Adolescent Marijuana Use: An Extension to the Theory of Planned Behavior

Despite research indicating that effective parenting plays an important protective role in adolescent risk behaviors, few studies have applied theory to examine this link with marijuana use, especially with national data. In the current study (N = 2,141), we hypothesized that parental knowledge (of adolescent activities and whereabouts) and parental warmth are antecedents of adolescents’ marijuana beliefs—attitudes, subjective norms, and perceived behavioral control—as posited by the Theory of Planned Behavior (TPB; Ajzen 1991). These three types of beliefs were hypothesized to predict marijuana intention, which in turn was hypothesized to predict marijuana consumption. Results of confirmatory factor analyses corroborated the psychometric properties of the two-factor parenting structure as well as the five-factor structure of the TPB. Further, the proposed integrative predictive framework, estimated with a latent structural equation model, was largely supported. Parental knowledge inversely predicted pro-marijuana attitudes, subjective norms, and perceived behavioral control; parental warmth inversely predicted pro-marijuana attitudes and subjective norms, ps < .001. Marijuana intention (p < .001), but not perceived behavioral control, predicted marijuana use 1 year later. In households with high parental knowledge, parental warmth also was perceived to be high (r = .54, p < .001). Owing to the analysis of nationally representative data, results are generalizable to the United States population of adolescents 12–18 years of age.     

General Practitioners’ intention to prescribe and prescribing patterns in selected European settings: The OTCSOCIOMED project

The aim of this paper is to explore general practitioners’ (GPs) prescribing intentions and patterns across different European regions using the Theory of Planned Behavior (TPB).A cross-sectional study was undertaken in selected geographically defined Primary Health Care areas in Cyprus, Czech Republic (CZ), France, Greece, Malta, Sweden and Turkey. Face-to-face interviews were conducted using a TPB-based questionnaire. The number of GP participants ranged from 39 to 145 per country. Possible associations between TPB direct measures (attitudes, subjective norms (SN) and perceived behavioral control (PBC)) and intention to prescribe were assessed by country.On average, GPs thought positively of, and claimed to be in control of, prescribing. Correlations between TPB explanatory measures and prescribing intention were weak, with TPB direct measures explaining about 25% of the variance in intention to prescribe in Malta and CZ but only between 3% and 5% in Greece, Sweden and Turkey. SN appeared influential in GPs from Malta; attitude and PBC were statistically significant in GPs from CZ. GPs’ prescribing intentions and patterns differed across participating countries, indicating that country-specific interventions are likely to be appropriate. Irrational prescribing behaviors were more apparent in the countries where an integrated primary care system has still not been fully developed and policies promoting the rational use of medicines are lacking. Demand-side measures aimed at modifying GPs prescribing behavior are deemed necessary.