Sociocultural influences on adolescent boys' body image and body change strategies

Society provides messages about how people should ideally look and previous research has indicated these messages, both the actual messages provided and the perception of the message, influence body image. Research into male body image has shown males are concerned with having a lean and muscular body and as such, may want to decrease fat and increase their muscles. This paper explored the influence of a range of messages from parents, peers, and the media on a number of different measures of 362 adolescent boys’ body image and body change strategies. Specifically, messages about shape, food, exercise, losing weight and increasing muscles were explored in relation to satisfaction with weight and muscles, and the use of strategies to decrease weight and increase muscles. The findings indicated that parental messages were the strongest influence on body image and that parents, the media, and to a lesser extent messages from male friends were the strongest predictors of body change strategies.

A longitudinal investigation of the development of weight and muscle concerns among preadolescent boys

The study examined the impact of body mass index (BMI), negative affect, self-esteem, and sociocultural influences in the development of weight and muscle concerns among preadolescent boys. Body dissatisfaction, importance placed on weight and muscles, weight loss strategies, and strategies to increase muscles were evaluated. Participants were 237 boys aged between 8 and 11 years who were tested at three assessment periods 8 months apart. The main predictor of boys’ body change strategies was their perceived pressures to modify weight and muscles from parents, peers, and the media. The other main predictor of boys’ body change strategies and the sole predictor of body dissatisfaction was BMI. Self-esteem and negative affect were found to be weak and generally nonsignificant predictors of boys’ body image concerns and body change strategies. Additional studies that examine the risk and protective factors associated with boys’ weight and muscle concerns are needed to assist in the development of prevention programs for preadolescent boys.

Evaluation of a prevention program to address body focus and negative affect among children

The current study evaluated a program to improve the body image and positive and negative affect of children. Participants were 368 children aged 8–12 years. The results demonstrated that boys placed more importance on and were less satisfied with their muscles; girls were less satisfied with their weight and the importance of weight increased with increasing age. Children with a large BMI were less satisfied with their weight. Boys in the intervention group showed reduced levels of negative affect over time. Further research is required to develop prevention and intervention programs to lower the effects of body dissatisfaction and negative affect among children.

Negative affect as a mediator between body dissatisfaction and extreme weight loss and muscle gain behaviors

Negative affect has been found to mediate the relationship between body dissatisfaction and bulimia. However, it is unknown if this relationship also applies to disordered eating, excessive exercise and strategies to increase muscle for men or women. The aim of this study was to investigate whether negative and positive affect mediate the relationship between body dissatisfaction, and these body change strategies. Respondents were 93 men and 97 women (age range: 18-25 years), who completed measures of body dissatisfaction, positive and negative affect and body change strategies to lose weight or increase muscles. Body dissatisfaction was associated with strategies to lose weight, dietary restraint and bulimia for both genders. Negative affect mediated the relationship between dissatisfaction with muscles and strategies to lose weight, dietary restraint and bulimia for women only. The results confirm previous findings related to the association between negative affect and disordered eating for women. They also demonstrate the need to further investigate the impact of negative affect on body change strategies, particularly among men, and those strategies related to increasing muscles.

Accuracy of body size estimation: Role of biopsychosocial variables

This study evaluated factors related to the perceptual disturbances of body image. Using a digital body image computer program, 191 participants (107 women, 82 men) adjusted an image of their body to the perceived actual size at five body regions; chest, waist, hips, thighs and calves. A neutral object (a vase) was also adjusted to partial out the level of perceptual distortion present with a neutral object. Men and women overestimated the size of the neutral object and their body image. Among women, overestimation was primarily predicted by high levels of depression, and media and peer influences to be thinner and increase muscles. Among men, overestimation was predicted by high BMI, media influences to lose weight and increase muscles, and peer influences to increase muscles. These findings suggest that perceptual accuracy of body image is primarily predicted by biopsychosocial influences.

Risk items associated with patient falls in oncology and medical settings

The aim of this study was to determine whether items on a falls risk-assessment tool, made up of brief cognitive and physical measures that nurses use in practice, differentiated fallers and nonfallers in oncology and medical settings. A measure of leg muscle strength clearly distinguished between fallers and nonfallers, with the latter having stronger leg muscles. For nursing practice, the assessment of patients' muscle strength seems to be the most useful scale for identifying potential fallers.

Interaction between playing golf and HRT on vertebral bone properties in post-menopausal women measured by QCT

Summary We investigated the effect of playing regular golf and HRT on lumbar and thoracic vertebral bone parameters (measured by QCT) in 72 post-menopausal women. The main finding of this study was that there was positive interaction between golf and HRT on vertebral body CSA and BMC at the thoracic 12 and lumbar 2 vertebra but not the third and seventh thoracic vertebras.

Introduction Identifying specific exercises that load the spine sufficiently to be osteogenic is an important component of primary osteoporosis prevention. The aim of this study was to determine if in postmenopausal women regular participation in golf resulted in greater paravertebral muscle mass and improved vertebral bone strength.

Methods Forty-seven postmenopausal women who played golf regularly were compared to 25 controls. Bone parameters at the mid-vertebral body were determined by QCT at spinal levels T3, T7, T12 and L2 (cross-sectional area (CSA), total volumetric BMD (vBMD), trabecular vBMD of the central 50% of total CSA, BMC and cortical rim thickness). At T7 and L2, CSA of trunk muscles was determined.

Results There was a positive interaction between golf and HRT for vertebral CSA and BMC at T12 and L2, but not at T3 or T7 (p ranging < 0.02 to 0.07). Current HRT use was associated with a 10–15% greater total and trabecular vBMD at all measured vertebral levels. Paravertebral muscle CSA did not differ between groups. Vertebral CSA was the bone parameter significantly related to muscle CSA.

Conclusion These findings provide preliminary evidence that playing golf may improve lower spine bone strength in postmenopausal women who are using HRT.

Emotional reactions following exposure to idealized bodies predict unhealthy body change attitudes and behaviors in women and men

Objective: We explored the extent to which changes in emotional states following exposure to images of idealized bodies predict unhealthy body change attitudes and behaviors in women and men, and whether particular psychological traits mediate these effects. Method: One hundred thirty-three women and 93 men were assessed for unhealthy attitudes and behaviors related to body weight and muscles using the Eating Disorder Inventory-2 (EDI-2), the Obligatory Exercise Questionnaire, and the strategies to increase muscles subscale of the Body Change Inventory. Psychological traits assessed included body dissatisfaction (EDI-2), internalization of the thin/athletic ideal (Sociocultural Attitudes Towards Appearance Questionnaire-3), body comparison (Body Comparison Scale), self-esteem (Rosenberg Self-Esteem Inventory), depression (Beck Depression Inventory-II), and identity confusion (Self-Concept Clarity Scale). Participants were then exposed to photographs of thin female models and muscular male models, and visual analogue scales were used to measure changes in postexposure state body dissatisfaction, anger, anxiety, and depression.
Results: Postexposure increases in state anger, anxiety, depression, and body dissatisfaction correlated with drive for thinness and disordered eating symptomatology in women, while postexposure increases in state body dissatisfaction correlated with muscle development in men. Analyses revealed that internalization and body comparison mediated these relationships, with trait body dissatisfaction, trait depression, self-esteem, and self-concept/identity confusion serving as mediators for women only. Conclusion: These results are indicative of gender differences in: (a) reactions to idealized bodies; (b) psychological traits that predispose individuals to experience these reactions; and (c) types of body change behavior that are associated with these reactions.

Where is all the pressure coming from? Messages from mothers and teachers about preschool children's appearance, diet and exercise

This study used interviews and qualitative analyses to investigate the nature of the messages that preschool children receive from mothers and teachers about their bodies, general appearance, exercise and eating practices. Participants were 10 female teachers and 53 mothers. The behaviours of the 53 children (24 boys, 29 girls) were also observed to determine the nature of their eating and exercise behaviours. The results demonstrated that both mothers and teachers expressed concerns about their own bodies. Mothers also communicated messages to their daughters about losing weight and messages to their sons about increasing their muscles. Both girls and boys were concerned about their appearance, particularly their clothes and hair. Girls also demonstrated some concerns about losing weight, and boys with increasing muscles. Implications of these results are discussed in terms of designing education programs for mothers, teachers and children to prevent the development of body image concerns and disordered eating among children. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association.

A longitudinal study of body change strategies of fitness center attendees

This study evaluated predictors of strategies to change weight and muscles among men and women who attend fitness centers. A questionnaire was completed by 107 men (mean age = 39.17, SD = 13.14), and 151 women (mean age = 35.31, SD = 11.38) who regularly attended fitness centers at two points in time, one year apart. The only unique predictor of body change strategies over time for men was body dissatisfaction predicting drive for thinness; for women, body dissatisfaction predicted strategies to lose weight, drive for thinness, use of food supplements to lose weight and levels of bulimia. Media messages also predicted drive for thinness and bulimia among women. These findings would suggest that attendance body dissatisfaction is an important factor predicting other normative and health risk behaviors among fitness center attendees, particularly women at a fitness center over a 12 month period was not generally associated with adverse health risk behaviors.

Interaction of exercise and diet on GLUT-4 protein and gene expression in type I and type II rat skeletal muscle

We determined the interaction of exercise and diet on glucose transporter (GLUT-4) protein and mRNA expression in type I (soleus) and type II [extensor digitorum longus (EDL)] skeletal muscle. Forty-eight Sprague Dawley rats were randomly assigned to one of two dietary conditions: high-fat (FAT, n =24) or high-carbohydrate (CHO, n =24). Animals in each dietary condition were allocated to one of two groups: control (NT, n =8) or a group that performed 8 weeks of treadmill running (4 sessions week^–1 of 1000 m @ 28 m min^–1 , RUN, n =16). Eight trained rats were killed after their final exercise bout for determination of GLUT-4 protein and mRNA expression: the remainder were killed 48 h after their last session for measurement of muscle glycogen and triacylglycerol concentration. GLUT-4 protein expression in NT rats was similar in both muscles after 8 weeks of either diet. However, there was a main effect of training such that GLUT-4 protein was increased in the soleus of rats fed with either diet (P < 0.05) and in the EDL in animals fed with CHO (P < 0.05). There was a significant diet–training interaction on GLUT-4 mRNA, such that expression was increased in both the soleus (100% ↑P < 0.05) and EDL (142% ↑P < 0.01) in CHO-fed animals. Trained rats fed with FAT decreased mRNA expression in the EDL (↓ 45%, P < 0.05) but not the soleus (↓ 14%, NS). We conclude that exercise training in CHO-fed rats increased both GLUT-4 protein and mRNA expression in type I and type II skeletal muscle. Despite lower GLUT-4 mRNA in muscles from fat-fed animals, exercise-induced increases in GLUT-4 protein were largely preserved, suggesting that control of GLUT-4 protein and gene expression are modified independently by exercise and diet.

Mechanisms that contribute to differences in motor performance between young and old adults

This paper examines the physiological mechanisms responsible for differences in the amplitude of force fluctuations between young and old adults. Because muscle force is a consequence of motor unit activity, the potential mechanisms include both motor unit properties and the behavior of motor unit populations. The force fluctuations, however, depend not only on the age of the individual but also on the muscle group performing the task, the type and intensity of the muscle contraction, and the physical activity status of the individual. Computer simulations and experimental findings performed on tasks that involved single agonist and antagonist muscles suggest that differences in force fluctuations are not attributable to motor unit twitch force, motor unit number, or nonuniform activation of the agonist muscle, but that they are influenced by the variability and common modulation of motor unit discharge in both the agonist and antagonist muscles. Because the amplitude of the force fluctuations does not vary linearly with muscle activation, these results suggest that multiple mechanisms contribute to the differences in force fluctuations between young and old adults, although the boundary conditions for each mechanism remain to be determined.