Managing symptoms and health through self-prescribed restrictive diets: What can general practitioners learn from the phenomenon of wheat avoidance?

BACKGROUND: Seven per cent of Australian adults report avoiding wheat products for the relief of symptoms. The objective of this study was to explore the experiences, symptoms, influences and beliefs that may explain the tendency for this behaviour to occur pre-dominantly in the absence of a reported medical diagnosis or expert dietary supervision. METHODS: Data were collected through preliminary questionnaires and semi-structured interviews with 35 self-identified symptomatic individuals who avoid consumption of wheat-based products without a diagnosis of coeliac disease or wheat allergy. RESULTS: Like other contested health phenomena, symptomatic wheat avoidance is characterised by broad symptomatology, perceived benefits, absence of clear biological markers, dissatisfaction with conventional medicine following previous negative test results, and the fact that presumed treatment - elimination of a dietary factor - requires no medical intervention. DISCUSSION: Self-prescribed food avoidance represents a diagnostic and therapeutic challenge for practitioners, central to which is a tension between patient expectations and biomedical standards of evidence in the diagnostic relationship.

Food avoidance in an Australian adult population sample: the case of dairy products.

OBJECTIVE: To assess the prevalence of and explanations for the avoidance of dairy foods, including symptoms attributed to their consumption, diagnoses and psychological predictors of avoidance. Also considered were comparisons with symptom-related avoidance of wheat in the same sample. DESIGN: Cross-sectional population survey. SETTING: The study was conducted in Australia using a national postal omnibus survey. SUBJECTS: Adults aged 18 years and over (n 1184; 52·9 % female) selected at random from the Australian Electoral Roll. RESULTS: Despite few claims of formally diagnosed allergy or intolerance, 11·8 % of the sample reported avoiding dairy products because of adverse physiological effects, which commonly included gastrointestinal symptoms. Unlike wheat (3·5 %) or wheat-and-dairy (3·6 %) avoidance, dairy avoidance (8·2 %) was predicted by age (negatively) and worry about illness (positively). CONCLUSIONS: The findings are further evidence of a widespread tendency for consumers to exercise control over their health by eliminating dietary factors considered suspect without medical evidence or oversight. Unanswered questions include the decision processes underlying dairy avoidance, whether symptoms are attributed correctly, the agents and physiological mechanism(s) involved, the relative contributions of symptom severity and vigilance to the association with illness worry, and the nutritional adequacy of dairy avoiders' diets. Irrespective of the accuracy of self-diagnoses, if the elimination of suspect foods is an end in itself the paradoxical possibility for nutritional imbalances may have significant public health implications.

Motivations for avoiding wheat consumption in Australia: results from a population survey.

OBJECTIVE: To assess the prevalence of and explanations for wheat avoidance, including reported symptoms, diagnoses and information sources influencing the decision to avoid wheat, and to investigate potential psychological predictors of this behaviour. DESIGN: Cross-sectional population survey. SETTING: The study was conducted in Australia, using a nationwide postal omnibus survey. SUBJECTS: Adults aged 18 years and over (n 1184; 52·9% female) selected at random from the Australian Electoral Roll. RESULTS: With cases of stated and suspected coeliac disease (1·2%) excluded, 7·3% of the sample reported adverse physiological effects, predominantly gastrointestinal, that they associated with wheat consumption. Few among this group (5·7%) claimed a formally diagnosed intolerance or allergy requiring avoidance of wheat-based foods. Symptomatic wheat avoidance was highly correlated with dairy avoidance and predicted by gender (female), lesser receptiveness to conventional medicine and greater receptiveness to complementary medicine, but not by neuroticism, reasoning style or tendency to worry about illness. CONCLUSIONS: The data indicate that many adult Australians are consciously avoiding consumption of wheat foods, predominantly without any formal diagnosis. Reported symptoms suggest a physiological but not allergenic basis to this behaviour. Questions to be answered concern whether symptoms are attributed correctly to wheat, the agents (wheat components, dietary factors or additives) and physiological mechanism(s) involved, the nutritional adequacy of avoiders' diets, and the clinical and psychosocial processes that lead a substantial number of adults to avoid consuming wheat (or any other dietary factor) apparently independently of a medical diagnosis.

Treatment beliefs and preferences for psychological therapies for weight management.

OBJECTIVE: Treatment beliefs and preferences for psychological therapies were investigated in 80 overweight individuals trying to manage their weight. METHOD: Participants read 4 therapy descriptions: cognitive behavioral therapy (CBT), behavior therapy (BT), cognitive therapy (CT), and acceptance and commitment therapy (ACT). They ranked the treatments in order of preference, explained the reason for their preferred choice, and reported their beliefs about each approach. RESULTS: Individual CBT (43.42%) and BT (31.58%), delivered face-to-face or technologically, were the most preferred treatment options, while ACT (17.12%) and CT (7.89%) were the least preferred. The main reasons cited among those who chose CBT and BT were perceived comprehensiveness and the practical nature of the approach, respectively. Treatment beliefs were strongly predicted by psychological need satisfaction as well as perceived ease and effort. CONCLUSIONS: Further research should ascertain the stability of treatment beliefs and the efficacy of modifying the treatment context to meet individual needs.

Perceptions of portion size and energy content: implications for strategies to affect behaviour change.

OBJECTIVE: To assess Australian consumers' perception of portion size of fast-food items and their ability to estimate energy content. DESIGN: Cross-sectional computer-based survey. SETTING: Australia. SUBJECTS: Fast-food consumers (168 male, 324 female) were asked to recall the items eaten at the most recent visit to a fast-food restaurant, rate the prospective satiety and estimate the energy content of seven fast-food or 'standard' meals relative to a 9000 kJ Guideline Daily Amount. Nine dietitians also completed the energy estimation task. RESULTS: Ratings of prospective satiety generally aligned with the actual size of the meals and indicated that consumers perceived all meals to provide an adequate amount of food, although this differed by gender. The magnitude of the error in energy estimation by consumers was three to ten times that of the dietitians. In both males and females, the average error in energy estimation for the fast-food meals (females: mean 3911 (sd 1998) kJ; males: mean 3382 (sd 1957) kJ) was significantly (P < 0·001) larger than for the standard meals (females: mean 2607 (sd 1623) kJ; males: mean 2754 (sd 1652) kJ). In women, error in energy estimation for fast-food items predicted actual energy intake from fast-food items (ß = 0·16, P < 0·01). CONCLUSIONS: Knowledge of the energy content of standard and fast-food meals in fast-food consumers in Australia is poor. Awareness of dietary energy should be a focus of health promotion if nutrition information, in its current format, is going to alter behaviour.

Parent- and child-reported parenting. Associations with child weight-related outcomes.

The present study aimed to investigate associations of both parent-reported and child-perceived parenting styles and parent-reported parenting practices with child weight and weight-related behaviours. Participants were 175 children (56% female) aged between 7 and 11, and their primary caregivers (91% female), recruited through South Australian primary schools. Children completed measures of parenting style, attitude toward fruit, vegetables, and non-core food, and attraction to physical activity. Parents completed measures of parenting style and domain-specific parenting practices (feeding and activity-related practices) and reported on child dietary intake, physical activity, and sedentary behaviour. Objective height and weight measurements were taken from children, from which body mass index (BMI) was calculated. Child-reported parenting style and parent-reported parenting practices were uniquely associated with child weight-related outcomes, but styles and practices did not interact in their association with child outcomes. Child-reported parenting style was associated with child food and activity attitudes, whereas parent-reported parenting style was not associated with child outcomes. The findings of the present study generally support the recommendation of a parenting style high in demandingness and responsiveness for supporting healthy child weight-related behaviours, along with appropriate domain-specific practices. The child's perspective should be incorporated into research involving child outcomes wherever possible.

Does meal duration predict amount consumed in lone diners? An evaluation of the time-extension hypothesis.

The time-extension hypothesis has been proposed to describe why social facilitation (the tendency for presence of co-eaters to increase the amount eaten) occurs amongst groups of diners. However, it is possible that time-extension could increase the amount eaten in the absence of social effects. Therefore, the aim of this study was to assess whether prolonged exposure to a food environment without social interaction could increase consumption. Lone diners (n=141) were observed eating in a fast food environment. The items consumed, meal duration, estimated demographics (sex, weight status and age) and whether or not the participant was reading were recorded unobtrusively. Lone diners who were reading spent longer eating (M=17.36; SD=8.23) than those who were not (M=8.88; SD=5.47), but energy intake was less than 200 kJ greater, and not overall related to time spent eating. The fact that time-extension did not alter the amount eaten in lone diners is discussed in the context of previous studies and the theory of social facilitation.

Determinants of fast-food consumption. An application of the Theory of Planned Behaviour.

This study applied and extended the Theory of Planned Behaviour (TPB; Ajzen, 1988) in an examination of the variables influencing fast-food consumption in an Australian sample. Four hundred and four participants responded to items measuring TPB constructs and retrospective and prospective measures of fast-food consumption. Additional independent variables included: Consideration of Future Consequences (Strathman, Gleicher, Boninger, & Edwards, 1994), Fear of Negative Evaluation (Leary, 1983), and Self-Identification as a Healthy Eater Scale (Armitage & Conner, 1999a). Structural Equation Modeling (SEM) was used to examine predictors of consumption. SEM indicated that the TPB successfully predicted fast-food consumption. Factor analyses assisted in the definition of constructs that underlay attitudes towards fast foods. These constructs were included in an 'extended' TPB model which then provided a richer source of information regarding the nature of the variables influencing fast-food consumption. Findings suggest that fast-food consumption is influenced by specific referent groups as well as a general demand for meals that are tasty, satisfying, and convenient. These factors reflect immediate needs and appear to override concerns about longer-term health risks associated with fast food. Results are discussed in the context of possible applications.

Engagement with dietary fibre and receptiveness to resistant starch in Australia.

OBJECTIVE: To investigate community engagement with the health benefits of dietary fibre (DF) and its potential as a framework for the promotion of increased consumption of resistant starch (RS). SETTING: A nationwide postal Food and Health Survey conducted in Australia by CSIRO Human Nutrition. SUBJECTS: Adults aged 18 years and above, selected at random from the Australian Electoral Roll (n 849). DESIGN: A cross-sectional design was employed to analyse ratings of (i) the importance of various RS health and functional claims and (ii) receptiveness to different foods as RS delivery vehicles, according to the respondents' level of fibre engagement as classified under the Precaution Adoption Process Model (PAPM) of Health Behaviour. RESULTS: There was a high level of recognition (89·5 %) of DF as being important for health. Significant gender differences were found for ratings of RS attributes and RS delivery options. Women were both more fibre-engaged than men and more receptive than men to RS and its potential benefits. Ratings of the acceptability of several foods as means of delivering RS revealed a general preference for healthy staples over indulgences, with the margin between acceptability of staples and indulgences increasing markedly with increased fibre engagement. CONCLUSIONS: Application of the PAPM to awareness of DF reveals a ready-made target group for health messages about RS and pockets of differential potential receptiveness. The findings support the promotion of RS as providing health benefits of DF with the added reduction of risk of serious disease, its delivery through healthy staples and the targeting of messages at both fibre-engaged individuals and women in general.

Thinking about going wheat-free? Evidence of nutritional inadequacies in the dietary practices of wheat avoiders.

AIM: To assess dietary intake and nutritional adequacy amongst self-identified symptomatic wheat-avoiders. METHODS: Thirty-four self-identified symptomatic avoiders of wheat-based products without a diagnosis of coeliac disease or wheat allergy were recruited to participate in a dietary assessment study. Dietary intake was assessed via a three-day weighed food record. Participants were aged 33 to 83 years, were predominantly women (n = 30) and had been avoiding wheat for a mean of six years. Nutrient intakes were compared with Nutrient Reference Values. Food group intakes were assessed and consumption of wheat-containing and wheat-free cereal-based foods described. RESULTS: Inadequate intakes of key protective nutrients such as fibre and calcium were common; many participants reported avoiding dairy as well as wheat. Intakes of total and saturated fat exceeded recommendations. Although 85% of the sample reported avoiding all wheat products, at least one third of cereal products and dishes consumed in this group, comprising mostly discretionary-type foods, were wheat based. CONCLUSIONS: Dietary intake patterns and resulting nutrient imbalances in individuals restricting or eliminating wheat to manage symptoms are cause for concern. The situation is likely exacerbated by the tendency for many wheat avoiders to report also avoiding other foods, especially dairy products. A bi-disciplinary approach from medical practitioners and dietitians to individuals experiencing unexplained gastro-intestinal symptoms and strategies to support informed food choice is needed to combat longer-term health consequences of a diet with this nutritional profile.

Responses to GM food content in context with food integrity issues: results from Australian population surveys.

This study examined community responses to use of genetically modified (GM) content in food in the context of responses to familiar food additives by testing an empirically and theoretically derived model of the predictors of responses to both GM content and food integrity issues generally. A nationwide sample of 849 adults, selected at random from the Australian Electoral Roll, responded to a postal Food and Health Survey. Structural equation modelling analyses confirmed that ratings of general concern about food integrity (related to the presence of preservatives and other additives) strongly predicted negativity towards GM content. Concern about food integrity was, in turn, predicted by environmental concern and health engagement. In addition, both concern about food integrity generally and responses to GM content specifically were weakly predicted by attitudes to benefits of science and an intuitive (i.e., emotionally-based) reasoning style. Data from a follow-up survey conducted under the same conditions (N=1184) revealed that ratings of concern were significantly lower for use of genetic engineering in food than for four other common food integrity issues examined. Whereas the question of community responses to GM is often treated as a special issue, these findings support the conclusion that responses to the concept of GM content in food in Australia are substantially a specific instance of a general sensitivity towards the integrity of the food supply. They indicate that the origins of responses to GM content may be largely indistinguishable from those of general responses to preservatives and other common food additives.

The role of item extremity in the emergence of keying-related factors: an exploration with the life orientation test.

Keying-related factors in psychological scales are variously interpreted substantively or as products of violations of the assumptions underlying item keying. The present study investigated whether the extremity of the wording of items may contribute to the emergence of item-keying factors in a commonly used psychological scale. Respondents (N = 277) completed the Life Orientation Test (M. F. Scheier & C. S. Carver, 1985) in either its original or modified, more moderately worded form. Results indicate that the interaction of item extremity and item keying significantly affected subscale means and, more important, that the more moderately worded scale was substantially more unidimensional. Results are explained partially through the association of lesser and greater extremity with the tendency for some respondents to agree or disagree with items irrespective of keying direction. These results, although demonstrated in only 1 scale, have potential relevance to any scale comprising positive and negative items.

The efficacy of a self-managed Acceptance and Commitment Therapy intervention DVD for physical activity initiation.

OBJECTIVES: Initiating and maintaining physical activity presents the individual with challenges of inconvenience, discomfort, and counteractive energy. Addressing these challenges requires an intervention that elicits motivation to engage in this activity, minimizes the direct relationship between unwanted internal experiences and inaction, and is also in itself accessible and convenient. Accordingly, this study investigated the efficacy of a self-managed Acceptance and Commitment Therapy (ACT) intervention delivered via DVD and tailored for physical activity initiation. DESIGN AND METHODS: Fifty-nine minimally active community participants were randomly allocated to receive a 12-week pedometer-based walking programme, or the same walking programme with the additional provision of the ACT DVD. The primary outcome was overall physical activity level (assessed at baseline and post-intervention), and the secondary outcome was pedometer-assessed step count (measured at 4-weekly intervals throughout the intervention period). RESULTS: Participants who received the ACT DVD achieved a significantly greater increase in physical activity levels post-intervention, were more likely to achieve the goals specified in the programme, and reported a higher average step count than participants who received the walking programme in isolation. CONCLUSIONS: The ACT intervention, delivered via DVD for the promotion of physical activity, proved a simple, efficient, and accessible method to encourage positive short-term increases in an important health-promoting behaviour. Statement of contribution What is already known? ACT interventions can increase physical activity levels through augmenting initiatory self-regulatory control. Face-to-face delivery presents challenges of accessibility and feasibility for community implementation. There is a need for effective interventions that maximize impact while minimizing inconvenience. What does this study add? Supplementing a walking programme with a self-managed ACT DVD produced significant increases in physical activity. The ACT DVD is a convenient, accessible, and potentially cost-effective approach to physical activity initiation. ACT lends itself to implementation as a self-managed electronically delivered intervention.

Reduce temptation or resist it? Experienced temptation mediates the relationship between implicit evaluations of unhealthy snack foods and subsequent intake.

A more negative implicit evaluation of unhealthy food stimuli and a more positive implicit evaluation of a weight-management goal have been shown to predict lower consumption of unhealthy food. However, the associations between these evaluations, temptation to indulge and consumption of unhealthy food remain unclear. The current study investigated whether temptation would mediate the relationship between implicit food and goal evaluations and consumption (resembling an antecedent-focused route to self-control of eating), or whether those evaluations would moderate the relationship between temptation and consumption (resembling a response-focused route). A sample of 156 women (17-25 years), who tried to manage their weight through healthy eating, completed two implicit association tasks assessing implicit food and goal evaluations, respectively. Intake of four energy-dense snack foods was measured in a task disguised as a taste test, and participants reported the strength of experienced temptation to indulge in the snacks offered. Negative implicit food evaluation was associated with lower snack intake, and temptation mediated this relationship. Implicit goal evaluation was unrelated to both temptation strength and snack consumption. The findings contribute to an understanding of how negative implicit unhealthy food evaluation relates to lower consumption, namely through the mediation of temptation to indulge in those foods.

Eating in groups: Do multiple social influences affect intake in a fast-food restaurant?

This study investigated multiple social influences to determine whether they affect amount eaten at a fast-food environment. Using observational methods, data on meal duration, foods eaten and personal characteristics were collected for 157 McDonald's patrons. Analysis of covariance revealed that female diners ate less kilojoules when eating in mixed- versus same-sex groups (adjusted difference = 967 kJ, p < .05), while male diners eating in mixed-sex company ate more in groups compared to pairs (adjusted difference = 1067 kJ, p = .019). Influences to increase and restrict the amount eaten can operate simultaneously in an eating environment with gender a critical factor for consideration.

Incidence and correlates of posttrauma symptoms in children from backgrounds of domestic violence.

In recent years, evidence has emerged of the presence of posttrauma symptoms in children from backgrounds of domestic violence. The present study examined the incidence and correlates of posttrauma symptoms in 56 children of mothers who had been residents in women's shelters in Adelaide, South Australia. The most frequently endorsed symptoms among this sample of children were being troubled by distressing thoughts, conscious avoidance, hypervigilance, and sleep difficulties. Twenty percent of children met the criteria for a diagnosis of posttraumatic stress disorder (PTSD). Children meeting full PTSD criteria scored significantly higher on measures of anxiety, depression, and dissociation. Results support the use of a posttrauma framework for understanding the effects on children of living with domestic violence.

A comparison of cognitive restructuring and cognitive defusion as strategies for resisting a craved food.

The present study investigated the effectiveness of two cognitive strategies for resisting a craved food. One-hundred-and-ten self-identified chocolate cravers were randomised to a waiting list control condition or to receive a 60-minute standardised group intervention on cognitive restructuring (CR) or cognitive defusion (CD). All participants were provided with a bag of chocolates which they were instructed to carry with them for seven days and try to resist eating; uneaten chocolates were returned at the end of the study period. Measures included chocolate consumption and other behavioural, cognitive and evaluative self-reported outcomes. Overall, the odds of abstinence from chocolate were 3.26 times higher for participants in the CD than the CR condition. The effect of the interventions depended on baseline cognitive distress levels; for individuals at high levels of cognitive distress the CD condition led to significantly more restraint from chocolate than both the CR and control conditions. In addition, CD led to greater self-reported improvements in eating behaviours during the study period and was rated significantly easier to use and apply than CR. CD is discussed as a simple and efficient approach to manage food cravings and, potentially, other behavioural contributors to obesity.

The role of empathy in anger arousal in violent offenders and university students.

A lack of empathic responsiveness toward others has been consistently identified as an important antecedent to aggressive behavior and violent crime, with many rehabilitation programs for violent offenders incorporating treatment modules that are specifically designed to increase offender empathy. This study examined the extent to which cognitive (perspective taking) and affective (empathic concern, personal distress) empathy predicted anger in a clinical (male prisoners convicted of a violent offense) and a nonclinical (student) sample. Perspective taking emerged as the strongest predictor of self-reported anger in response to an interpersonal provocation, as well as being most consistently related to scores on measures of general trait anger and methods of anger control. While the relationship between perspective taking and anger was apparent for offenders as well as students, the results did not support the idea that an inability to perspective take is a particular characteristic of violent offenders.

Homophily and contagion as explanations for weight similarities among adolescent friends.

PURPOSE: To determine whether weight-based similarities among adolescent friends result from social influence processes, after controlling for the role of weight on friendship selection and other confounding influences. METHODS: Four waves of data were collected from a grade 8 cohort of adolescents (N = 156, mean age = 13.6 years) over their initial 2 years of high school. At each wave, participants reported on their friendship relations with grade-mates and had their height and weight measured by researchers to calculate their body mass index (BMI). Newly developed stochastic actor-oriented models for social networks were used to simultaneously assess the role of weight on adolescents' friendship choices, and the effect of friends' BMIs on changes in adolescent BMI. RESULTS: Adolescents' BMIs were not significantly predicted by the BMI of their friends over the 16 months of this study. Similarities in the weights of friends were found to be driven predominantly by friendship selection, whereby adolescents, particularly those who were not overweight, preferred to initiate friendships with peers whose weight status (overweight/nonoverweight) was the same as their own. CONCLUSIONS: Weight-based similarities among friends were largely explained by the marginalization of overweight adolescents by their peers, rather than by the "contagion" of excess weight among friends. These findings highlight the importance of adequately modeling friendship selection processes when estimating social influence effects on adiposity.