Child and adolescent obesity: part of a bigger picture

The prevalence of childhood overweight and obesity has risen substantially worldwide in less than one generation. In the USA, the average weight of a child has risen by more than 5 kg within three decades, to a point where a third of the country's children are overweight or obese. Some low-income and middle-income countries have reported similar or more rapid rises in child obesity, despite continuing high levels of undernutrition. Nutrition policies to tackle child obesity need to promote healthy growth and household nutrition security and protect children from inducements to be inactive or to overconsume foods of poor nutritional quality. The promotion of energy-rich and nutrient-poor products will encourage rapid weight gain in early childhood and exacerbate risk factors for chronic disease in all children, especially those showing poor linear growth. Whereas much public health effort has been expended to restrict the adverse marketing of breastmilk substitutes, similar effort now needs to be expanded and strengthened to protect older children from increasingly sophisticated marketing of sedentary activities and energy-dense, nutrient-poor foods and beverages. To meet this challenge, the governance of food supply and food markets should be improved and commercial activities subordinated to protect and promote children's health.

Effects of a free school breakfast programme on school attendance, achievement, psychosocial function, and nutrition: a stepped wedge cluster randomised trial

BACKGROUND: Approximately 55,000 children in New Zealand do not eat breakfast on any given day. Regular breakfast skipping has been associated with poor diets, higher body mass index, and adverse effects on children's behaviour and academic performance. Research suggests that regular breakfast consumption can improve academic performance, nutrition and behaviour. This paper describes the protocol for a stepped wedge cluster randomised trial of a free school breakfast programme. The aim of the trial is to determine the effects of the breakfast intervention on school attendance, achievement, psychosocial function, dietary habits and food security.

METHODS/DESIGN: Sixteen primary schools in the North Island of New Zealand will be randomised in a sequential stepped wedge design to a free before-school breakfast programme consisting of non-sugar coated breakfast cereal, milk products, and/or toast and spreads. Four hundred children aged 5-13 years (approximately 25 per school) will be recruited. Data collection will be undertaken once each school term over the 2010 school year (February to December). The primary trial outcome is school attendance, defined as the proportion of students achieving an attendance rate of 95% or higher. Secondary outcomes are academic achievement (literacy, numeracy, self-reported grades), sense of belonging at school, psychosocial function, dietary habits, and food security. A concurrent process evaluation seeks information on parents', schools' and providers' perspectives of the breakfast programme.

DISCUSSION: This randomised controlled trial will provide robust evidence of the effects of a school breakfast programme on students' attendance, achievement and nutrition. Furthermore the study provides an excellent example of the feasibility and value of the stepped wedge trial design in evaluating pragmatic public health intervention programmes.

Dietary restraint and negative affect as mediators of body dissatisfaction and bulimic behavior in adolescent girls and boys

Stice's dual pathway model of dietary restraint and negative affect was examined in both adolescent girls and boys. Self-report measures assessing body dissatisfaction, dietary restraint, negative affect and bulimic behavior were administered to 267 girls and 199 boys aged between 12 and 16 years. The findings for the girls were consistent with Stice's model, in that they indicated that both dietary restraint and negative affect mediated the relationship between body dissatisfaction and bulimic behavior. For the boys who desired a thinner body size, only negative affect was found to mediate the relationship between body dissatisfaction and bulimic behavior. On the other hand, for boys who desired a larger body size, both body dissatisfaction and dietary restraint were found to exert an independent effect on bulimic behavior. As boys can aspire to two contrasting and seemingly opposite body size ideals, the findings highlight that the relationship between body dissatisfaction, dietary restraint, negative affect and bulimic behavior are more complex in males than in females. Further research using longitudinal designs is needed in order to test the directional and bidirectional nature of the observed interrelationships.

Self-esteem and negative affect as moderators of sociocultural influences on body dissatisfaction, strategies to decrease weight and strategies to increase muscles among adolescent boys and girls

The study was conducted to examine the impact of sociocultural influences and the moderating role of self-esteem and negative affect on body dissatisfaction and body change strategies for both adolescent boys and girls. Surveys designed to assess body dissatisfaction, body change strategies to decrease weight and increase muscles, perceived sociocultural pressures to lose weight and increase muscles, self-esteem and negative affect were administered to 587 boys and 598 girls aged between 11 and 15 years. The majority of respondents were from Anglo-Australian backgrounds (83%) with the remainder being from Asian and European non-English-speaking backgrounds. The sociocultural influences were found to significantly predict body dissatisfaction and body change strategies for both boys and girls. However, in the case of boys, self-esteem was found to moderate the impact of the sociocultural influences in predicting body change strategies. It was primarily the boys with low self-esteem who were more affected by the sociocultural pressures whereas the girls were affected independently of their self-esteem. Negative affect was also found to play a moderating role on some of the sociocultural influences in predicting strategies to increase muscles. Both boys and girls with higher levels of negative affect were more likely to be affected by sociocultural messages directed at increasing muscles. The results from the present study demonstrate that as well as examining the direct influence of sociocultural pressures, it is also important to examine how these may be moderated by self-esteem and negative affect.

Body image, strategies to change muscles and weight, and puberty. Do they impact on positive and negative affect among adolescent boys and girls?

The purpose of this study was to examine the impact of strategies to both decrease weight and increase muscle tone on negative (depression, anxiety) and positive affect among adolescent males and females. The respondents were 1185 adolescents (587 males, 598 females) who were enrolled in grades 7 and 9 (mean age for MALES=13.22 years; mean age for FEMALES=13.21 years). Respondents completed the Body Image and Body Change Inventory that assessed body image satisfaction, body image importance, body change strategies to decrease weight, body change strategies to increase muscle tone, and food supplements. Respondents also completed the Pubertal Development Scale, the depression and anxiety scales of the Depression Anxiety and Stress Scale, and the positive affect items from the Positive and Negative Affect Scale. Structural equation modelling was used to determine how body satisfaction and importance, body change strategies, and puberty impacted on depression, anxiety, and positive affect. The results demonstrated that for both boys and girls, there was a strong association between body change strategies and negative affect. For boys, body dissatisfaction did not predict negative affect, although this was a strong predictor for girls. Body change strategies did not strongly predict positive affect for either boys or girls, although body image satisfaction was a strong predictor for both genders. The implications of these findings for obtaining a better understanding of the role of pubertal development, body image, and body change strategies in predicting positive and negative affect among adolescent males and females are discussed.

Parent, peer and media influences on body image and strategies to both increase and decrease body size among adolescent boys and girls

This study investigated the nature of body image and body change strategies, as well as the sociocultural influences on these variables, among a group of 1,266 adolescents (622 males, 644 females). In particular, it investigated weight gain and increased muscle, as well as weight loss. It was found that females were less satisfied with their bodies and were more likely to adopt strategies to lose weight, whereas males were more likely to adopt strategies to increase weight and muscle tone. Respondents with higher body mass index (BMI) evidenced greater body dissatisfaction and more weight loss strategies, but there were no differences between BMI groups in weight gain or strategies to increase muscles. Weight gain and strategies to increase muscles were more likely to be undertaken by older adolescents, but there were no grade level differences in weight loss. Media influences to alter weight, as well as feedback from mother, father, and both male and female peers, were greater for females. There were few grade level or BMI differences in regard to any of the sociocultural influences. The importance of these findings in terms of providing a better understanding of factors which may lead to a disturbed body image and body change disorders, particularly among adolescent boys, is discussed.

Body image and body change techniques among young adolescent boys

The aim of the present study was to examine the level of body image disturbance among adolescent boys and to determine how body image disturbance was related to body change techniques. Twenty boys from year 7 (mean age = 12.55 years, SD = 0.61) and 20 boys from year 9 (mean age = 14.85 years, SD = 0.59) were interviewed individually about their body image and body change strategies. The boys were questioned about the importance and their satisfaction with their weight, body size, body shape, muscle tone and parts of their body and the frequency with which they used the following techniques: eating less to lose weight, eating more to gain weight, and exercise to change body size, shape or muscle tone. The results demonstrated that of those boys who wanted to change their body (50 per cent), 12 wanted to lose weight and eight wanted to gain weight. The most frequent strategy used to change body size or shape was exercise, rather than changing eating patterns. Year 7 boys were more satisfied with their weight than year 9 boys, and boys with a larger body mass index (BMI) were less satisfied with their muscle tone and more likely to change their eating habits to decrease their body size or shape than boys with a smaller BMI. The implications of these findings for obtaining a better understanding of how male body image and body change strategies are different from girls are discussed.

Adolescent parenthood : a costly mistake or a search for love?

Family life is changing worldwide and an increasing number of women are choosing single parenthood. Adolescents who become pregnant and early childbearers do not always become pregnant unintentionally; some actively plan pregnancy while others are ambivalent mainly about the timing. This paper reports on a study using an ethnographic approach that explored the mothering experiences of five sole-supporting Australian teenage mothers who had a child over six months of age. It focuses on the story of one of them, a young woman who gave birth at 16 and set up home for herself and her son. Early childbearing is often a response to adverse social conditions such as poverty or homelessness and is not uncommonly chosen by teenage girls from socially deprived backgrounds. Educational and employment opportunities may be limited, whilst motherhood may provide a purpose in life when few other options are possible. Young women who make this choice need comprehensive services to support them in the parenting role, including appropriate health care, welfare and housing benefits, and support in dealing with parenting, a role which they may greatly desire but are not automatically well prepared for.

Nutrition knowledge and food consumption: can nutrition knowledge change food behaviour?

The status and explanatory role of nutrition knowledge is uncertain in public health nutrition. Much of the uncertainty about this area has been generated by conceptual confusion about the nature of knowledge and behaviours, and, nutrition knowledge and food behaviours in particular. So the paper  describes several key concepts in some detail. The main argument is that 'nutrition knowledge' is a necessary but not sufficient factor for changes in consumers' food behaviours. Several classes of food behaviours and their causation are discussed. They are influenced by a number of environmental and intra-individual factors, including motivations. The interplay between motivational factors and information processing is important for nutrition promoters as is the distinction between declarative and procedural  knowledge. Consideration of the domains of nutrition knowledge shows that their utility is likely to be related to consumers' and nutritionists' particular goals and viewpoints. A brief survey of the recent literature shows that the evidence for the influence of nutrition knowledge on food behaviours is mixed. Nevertheless, recent work suggests that nutrition knowledge may play a small but pivotal role in the adoption of healthier food habits. The implications of this overview for public health nutrition are: (i) We need to pay greater attention to the development of children's and adults' knowledge frameworks (schema building); (ii) There is a need for a renewed proactive role for the education sector; (iii) We need to take account of consumers' personal food goals and their acquisition of procedural knowledge which will enable them to attain their goals; (iv) Finally, much more research into the ways people learn and use food-related knowledge is required in the form of experimental interventions and longitudinal studies.

Nutrition communication: do we need a new outlook?

The present paper will discuss the nature of nutrition communication and knowledge in relation to novel foods. The paper starts with an introduction to trends in present-day society, then focuses on the concepts of knowledge and information in relation to human needs and motivation. Next, the relevance of food and nutrition communication to consumer lifestyles is discussed. This is followed by consideration of consumer issues related to novel foods. The key conclusions are that nutrition communication is a minor part of most consumers' lifestyles and that the promotion of novel foods must be based on the dissemination of sound nutrition principles throughout the various values and lifestyles segments of the population.

The role of puberty, media and popularity with peers on strategies to increase weight, decrease weight and increase muscle tone among adolescent boys and girls

The present study was concerned with the impact of pubertal development, relationships with peers and perceived pressure from the media on body dissatisfaction and body change behaviors among adolescent boys and girls. In particular, the study investigated the underresearched area of strategies to increase weight and muscle. The exploration of body change strategies among adolescent boys has been a neglected area of research. Methods: Respondents were 1185 adolescents (527 males, 598 females) who were enrolled in Grades 7 and 9. Participants completed measures of pubertal development, media and peer influence, body dissatisfaction and strategies to lose weight, increase weight and to increase muscle. Results: The findings demonstrated that girls were more likely than boys to adopt strategies to lose weight, whereas boys were more likely to adopt strategies to increase muscle tone (but not weight). For boys in both Years 7 and 9, the main predictors of body change strategies were puberty and, to a lesser extent, perceived popularity with peers. The major influences for Years 7 and 9 girls were puberty and the media, but these mainly focused on weight loss. For Year 9 girls, perceived popularity with opposite-sex peers also predicted body dissatisfaction and strategies to increase muscle tone. Conclusion: The implications of these findings for understanding factors related to a range of body change strategies for adolescent boys and girls are discussed.

Psychometric evaluation of the body change inventory: an assessment instrument for adolescent boys and girls

A new instrument, the Body Change Inventory, was developed to provide an assessment of body change strategies that are used by both adolescent girls and boys. The novel aspect of this instrument is that it evaluates strategies to increase body size and increase muscle size, as well strategies to decrease body size. Independent samples of adolescent girls and boys aged between 11 and 17 years (N=1732) participated in four studies. The revised instrument consisted of three body change scales—Strategies to Decrease Body Size, Strategies to Increase Body Size, and Strategies to Increase Muscle Size. The studies demonstrated content validity, construct validity, internal consistency, and concurrent and discriminant validity for the new scales. The new scales provide a valuable addition in the literature for assessing three global body change strategies among adolescent girls and boys. They are needed in order to examine further the normative development of different kinds of body change strategies and how these may lead to behavioural problems such as disordered eating, exercise dependence, and steroid use.

General practitioners' perspectives regarding competence and confidentiality in an adolescent with suspected anorexia nervosa: legal and ethical considerations

In Victoria, Australia, the legal position regarding young people's competence to make medical treatment decisions has not been clarified in legislation, and a number of often vague common law decisions must be relied on for guidance. This situation produces a degree of uncertainty about appropriate professional practice, while also potentially impeding young people's rights claims in health care settings. With this in mind, the present research explored general practitioners' competence and confidentiality decisions regarding a 17-year-old female who presented with symptoms of an eating disorder. Questionnaires were sent to a random sample of 500 Victorian general practitioners, of whom 190 responded. After reading a case vignette, general practitioners indicated whether they would find the hypothetical patient competent and if they would maintain her confidentiality. Seventy-three per cent of respondents found the patient competent and most would have maintained confidentiality, at least initially. However, subsequent analysis of the rationales supplied for these decisions revealed a wide diversity in general practitioners' understandings and implementations of extant legal authority. This research highlights the need for general practitioners to be exposed to up-to-date and clinically relevant explanations of contemporary legal positions.