Despite the poor prognosis of dieting in obesity management, which often results in repeated attempts at weight loss and hence weight cycling, the prevalence of dieting has increased continuously in the past decades in parallel to the steadily increasing prevalence of obesity. However, dieting and weight cycling are not limited to those who are obese or overweight as substantial proportions of the various population groups with normal body weight also attempt to lose weight. These include young and older adults as well as children and adolescents who perceive themselves as too fat (due to media, parental and social pressures), athletes in weight-sensitive competitive sports (i.e. mandatory weight categories, gravitational and aesthetic sports) or among performers for whom a slim image is professionally an advantage. Of particular concern is the emergence of evidence that some of the potentially negative health consequences of repeated dieting and weight cycling are more readily seen in people of normal body weight rather than in those who are overweight or obese. In particular, several metabolic and cardiovascular risk factors associated with weight cycling in normal-weight individuals have been identified from cross-sectional and prospective studies as well as from studies of experimentally induced weight cycling. In addition, findings from studies of experimental weight cycling have reinforced the notion that fluctuations of cardiovascular risk variables (such as blood pressure, heart rate, sympathetic activity, blood glucose, lipids and insulin) with probable repeated overshoots above normal values during periods of weight regain put an additional stress on the cardiovascular system. As the prevalence of diet-induced weight cycling is increasing due to the opposing forces of an 'obesigenic' environment and the media pressure for a slim figure (that even targets children), dieting and weight cycling is likely to become an increasingly serious public health issue.

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Dieting and weight cycling as risk factors for cardiometabolic diseases: who is really at risk?

It is commonly assumed that a person identifying that they are ‘overweight’ is an important prerequisite to successful weight management. However, there has been no systematic evaluation of evidence supporting this proposition. The aim of the present research was to systematically review evidence on the relationship between perceived overweight and (i) weight loss attempts, (ii) weight control strategies (healthy and unhealthy), (iii) weight‐related behaviours (physical activity and eating habits), (iv) disordered eating and (v) weight change. We synthesized evidence from 78 eligible studies and evaluated evidence linking perceived overweight with outcome variables separately according to the gender, age and objective weight status of study participants. Results indicated that perceived overweight was associated with an increased likelihood of attempting weight loss and with healthy and unhealthy weight control strategies in some participant groups. However, perceived overweight was not reliably associated with physical activity or healthy eating and was associated with greater disordered eating in some groups. Rather than being associated with improved weight management, there was consistent evidence that perceived overweight was predictive of increased weight gain over time. Individuals who perceive their weight status as overweight are more likely to report attempting weight loss but over time gain more weight.

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A systematic review of the relationship between weight status perceptions and weight loss attempts, strategies, behaviours and outcomes.

The present study describes findings in relation to perceived body size and 'desire for thinness' by age and residential areas ('metropolitan areas', 'large cities', 'small cities' and 'towns') among young Japanese women. Data on 1731 non-pregnant, non-lactating women aged 15-39 years from the 1998 National Nutrition Survey of Japan were used. Current body size was evaluated by BMI percentiles (lean, or =95th), calculated for 5-year age groups. Perceived body size was obtained by self-report. We defined 'overestimation' as non-overweight, non-obese women who perceived themselves as being 'overweight' or 'obese'. Desired body size was evaluated by applying the desired BMI to these cut-off points. Of all the women, 48.4% perceived themselves as being 'overweight' or 'obese', and 43.7% desired a 'lean' or 'underweight' body size. Adjusted for the current BMI, the OR for 'overestimation' calculated by a logistic regression model was significantly elevated in the 15-19-year age group (OR 2.79; 95% CI 1.76, 4.43), compared with the 25-29-year age group. The OR for 'desire for thinness' was significantly high in the 35-39-year age group (OR 2.74; 95% CI 1.93, 3.89) and the 15-19-year age group (OR 2.26; 95% CI 1.57, 3.24). Women living in metropolitan areas had higher OR for 'desire for thinness' (but not for 'overestimation') than did women in towns (OR 1.47; 95% CI 1.05, 2.07). The findings suggest the nature of excessive weight concerns of young women in Japan; thus efforts to control such health-risk behaviours at a national level are urgent.

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Perceived body size and desire for thinness of young Japanese women: a population-based survey

Disordered eating behaviors and substance use are two risk factors for the development of serious psychopathology and health concerns in adulthood. Despite the negative outcomes associated with these risky behaviors, few studies have examined potential associations between these risk factors as they occur during adolescence. The importance of accurate or inaccurate weight perception among adolescents has received increased interest given documented associations with nutritional beliefs and weight management strategies. This study examined the associations among the perceptions of weight and substance use with disordered eating behaviors among a diverse sample of normal weight and overweight adolescent males and females. Data came from the 2007 National Youth Risk Behavior Survey (YRBS). The sample consisted of 11,103 adolescents (53.4% female; 44% Caucasian, 21% African American; 13% Hispanic; age responses ranged from 12 and under to 18 and over), with 31.5% meeting criteria for being either at-risk for obesity or already obese (i.e., overweight). As hypothesized, overestimation of weight among normal weight adolescents and accurate perceptions of weight among overweight adolescents were associated with higher rates of disordered eating behaviors. In normal weight adolescents, use of all three substances (tobacco, binge drinking, and cocaine) was associated with each disordered eating behavior. In contrast, findings revealed differences for overweight adolescents between the type of substance use and disordered eating behavior. Post hoc analyses revealed that gender moderated some of these relationships among overweight individuals. Implications for the development and implementation of secondary prevention programs aimed at reducing disordered eating behaviors, substance use, and obesity risk among normal and overweight adolescents are considered.

Weight Perception, Substance Use, and Disordered Eating Behaviors: Comparing Normal Weight and Overweight High-School Students

https://www.academicpedsjnl.net/article/S1876-2859(13)00103-4/pdf

Accuracy of child and adolescent weight perceptions and their relationships to dieting and exercise behaviors: a NHANES study.

Weight perceptions and weight control behaviors have been documented with underweight and overweight adolescents, yet limited information is available on normal weight adolescents. This study investigates the prevalence of overweight misperceptions and weight control behaviors among normal weight adolescents in the U.S. by sociodemographic and geographic characteristics. We examined data from the 2003 Youth Risk Behavior Survey (YRBS). A total of 9,714 normal weight U.S. high school students were included in this study. Outcome measures included self-reported height and weight measurements, overweight misperceptions, and weight control behaviors. Weighted prevalence estimates and odds ratios were computed. There were 16.2% of normal weight students who perceived themselves as overweight. Females (25.3%) were more likely to perceive themselves as overweight than males (6.7%) (p < 0.05). Misperceptions of overweight were highest among white (18.3%) and Hispanic students (15.2%) and lowest among black students (5.8%). Females (16.8%) outnumbered males (6.8%) in practicing at least one unhealthy weight control behavior (use of diet pills, laxatives, and fasting) in the past 30 days. The percentage of students who practiced at least one weight control behavior was similar by ethnicity. There were no significant differences in overweight misperception and weight control behaviors by grade level, geographic region, or metropolitan status. A significant portion of normal weight adolescents misperceive themselves as overweight and are engaging in unhealthy weight control behaviors. These data suggest that obesity prevention programs should address weight misperceptions and the harmful effects of unhealthy weight control methods even among normal weight adolescents.

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Karen A. Joye

Papers

Prevalence of overweight misperception and weight control behaviors among normal weight adolescents in the United States.