Psychosocial and behavioral correlates of dieting among overweight and non-overweight adolescents

PurposeTo examine correlates of dieting behavior in overweight and non-overweight youth.MethodsData came from Project EAT (Eating Among Teens), a study of eating and weight-related attitudes, behaviors, and psychosocial variables among 4746 adolescents in public schools. Logistic regression was used to compare dieters and non-dieters, and to examine interactions of dieting and overweight status.ResultsApproximately one third (31.8%) of the sample was overweight. Dieting in the previous year was reported by 55.2% of girls and 25.9% of boys. Dieting was associated with similarly elevated rates of extreme weight control behaviors, body dissatisfaction, and depression in both the non-overweight and overweight groups for both boys and girls. Girls reporting dieting behavior in both the non-overweight and overweight groups had similarly elevated risk for cigarette use, alcohol use, and marijuana use.ConclusionsThe negative correlates of dieting are similarly common among teens of varying weight status. These data suggest that dieting may not be a preferred method of weight management, even for overweight adolescents. Regardless of weight status, dieting may be a marker for other unhealthy behaviors and depressed mood in adolescents.     

Unhealthy behaviors and psychosocial difficulties among overweight adolescents: the potential impact of familial factors.

PURPOSE: To compare overweight and non-overweight youth on a selection of self-reported eating, physical activity, dieting, educational, and emotional variables and identify familial factors that serve as protective forces against unhealthy behaviors and psychosocial difficulties among overweight adolescents. METHODS: Data were taken from a 1996 cross-sectional school-based survey of 9957 adolescents in grades 7, 9, and 11. Based on self-reported heights and weights, respondents were categorized as "overweight" (body mass index) > or =85th percentile or "non-overweight." Student's t-tests were used to compare the non-overweight and overweight sample on the self-reported health-related behaviors and psychosocial variables. Logistic and linear regressions were used to identify familial factors associated with a reduced risk of engaging in unhealthy behaviors and experiencing psychosocial distress. RESULTS: Overweight adolescents reported engaging in significantly more unhealthy behaviors and experiencing more psychosocial distress than their non-overweight peers. Among the overweight youth, higher levels of reported family connectedness and parental expectations and moderate levels of parental monitoring were associated with the lowest levels of unhealthy behaviors and psychosocial distress. CONCLUSIONS: Satisfying and developmentally appropriate parent-adolescent relationships are associated with reduced behavioral and psychosocial risk factors associated with overweight during adolescence.     

Do physicians discuss needed diet and nutrition health topics with adolescents?

PurposePreventive services guidelines recommend screening all adolescents for diet habits, physical activity and growth, counseling underweight teens about body image and dieting patterns, and counseling overweight or obese teens about dietary habits and exercise. In this study, we assess whether adolescents at risk for overweight or for eating disorders have discussed recommended diet and nutrition topics with their physicians.MethodsWe surveyed 14–18-year-old adolescents who had been seen for well care in primary care pediatric and family medicine practices. Adolescents self-reported their weight, height, body image, dieting habits, and issues they had discussed with their clinicians. Body mass index (BMI) was used to define those “at risk for an eating disorder” (< 5% BMI), “at risk of becoming overweight” (85%–95% BMI), and “overweight” (> 95% BMI).ResultsA total of 8384 adolescents completed surveys (72% completion rate). Nearly one-third of adolescents were “at risk” or overweight. Females were less likely to be overweight than males (9.4% vs. 15.7%; p < .001). Although 26.4% were attempting to lose weight, only 12.2% of all teens were actually overweight. Exercise and restricting intake were the preferred methods of weight loss. Physicians routinely discussed adolescents’ weight during visits, and were more likely to discuss it with those “at risk” (p < .001). Body image was more often discussed with girls than with boys (52% vs. 44.6%, p < .001) and with those at risk (51.6% vs. 45.5%; p < .001). Discussion of healthy eating and weight loss occurred more often with adolescents “at risk” for becoming overweight (p < .001).ConclusionsMany adolescents are at risk for being overweight or are currently overweight, confirming the importance of clinicians discussing diet and nutrition health topics with all teens. Many adolescents also misclassify their body image, and hence perceive their body image to be different from their actual BMI; clinicians should discuss body image with all adolescents, not just those at risk for eating disorders. Better interventions are needed to promote healthy nutrition and physical activity to all adolescents.     

Structure analysis of the Children's Eating Attitudes Test in overweight and at-risk for overweight children and adolescents

BACKGROUND: In school-based samples of children, the Children's Eating Attitudes Test (ChEAT) has a four-factor structure; however, previous studies have not examined its factor structure in samples restricted to overweight youth. METHODS: The ChEAT was administered to 220 overweight (BMI>or=95th percentile) and 45 at-risk for overweight (BMI 85th-<95th percentile) children and adolescents. Factors were identified by a principal component analysis with varimax rotation. ChEAT factor scores of children with BMI>or=85th percentile were contrasted with those of 152 non-overweight (BMI 5th to <85th percentile) children and adolescents. RESULTS: Factor analysis generated four subscales described as 'body/weight concern,' 'food preoccupation,' 'dieting,' and 'eating concern.' ChEAT total score, body/weight concern, and dieting subscale scores were positively related to BMI-Z and body fat mass (p's<.05). Compared to non-overweight children, overweight and at-risk for overweight children had higher ChEAT total (9.9+/-7.4 vs. 6.6+/-7.8, p<.001), body/weight concern (3.2+/-3.1 vs. 1.3+/-3.0, p<.001), and dieting (1.8+/-2.2 vs. .8+/-2.3, p<.001) subscale scores. CONCLUSIONS: The previously elucidated factor structure of the ChEAT was primarily supported in a sample of overweight children. The emergence of separate body/weight concern and dieting subscales may relate to these children's experiences with attempted weight reduction.     

Validation of self-reported height and weight in fifth-grade Korean children

Height and weight are important indicators to calculate Body Mass Index (BMI); measuring height and weight directly is the most exact method to get this information. However, it is ineffective in terms of cost and time on large population samples. The aim of our study was to investigate the validity of self-reported height and weight data compared to our measured data in Korean children to predict obese status. Four hundred twenty-two fifth-grade (mean age 10.5 ± 0.5 years) children who had self-reported and measured height and weight data were final subjects for this study. Overweight/obese was defined as a BMI of or above the 85th percentile of the gender-specific BMI for age in the 2007 Korean National Growth Charts or a BMI of 25 or higher (underweight : < 5th, normal : ≥ 5th to < 85th, overweight : ≥ 85th to < 95th). The differences between self-reported and measured data were tested using paired t-test. Differences based on overweight/obese status were tested using analysis of variance (ANOVA) and linear trends. Pearson''s correlation and Cohen''s kappa were tested to examine agreements between the self-reported and measured data. Although measured and self-reported height, weight and BMI were significantly different and children tended to overreport their height and underreport their weight, the correlation between the two methods of height, weight and BMI were high (r = 0.956, 0.969, 0.932, respectively; all P < 0.001), and both genders reported their overweight/non-overweight status accurately (Cohen''s kappa = 0.792, P < 0.001). Although there were differences between the self-reported and our measured methods, the self-reported weight and height was valid enough to classify overweight/obesity status correctly, especially in non-overweight/obese children. Due to bigger underestimation of weight and overestimation of height in obese children, however, we need to be aware that the self-reported anthropometric data were less accurate in overweight/obese children than in non-overweight/obese children.     

肥胖、超重青少年通气功能与体成分关系

目的了解肥胖、超重和体重正常青少年的通气功能差异,探讨体成分对通气功能的影响.方法对研究对象测量身高、体重、腰围、臀围,采用中国肥胖问题工作组肥胖、超重筛查标准,对筛选出的肥胖(64人)、超重(56人)和对照(75人)3组青少年进行体成分和通气功能测定.结果3组青少年用力肺活量(FVC)测量值肥胖组＞超重组＞对照组,差异无统计学意义(F=25.213,P=0.000).单位体重深吸气量(IC)、单位体表面积最大通气量(MVV)均表现为对照组＞超重组＞肥胖组,差异有统计学意义(F=10.316,P=0.000;F=9.660,P=0.000).3组青少年小气道功能差异无统计学意义.肥胖、超重男生体重及瘦体重含量与通气功能呈显著正相关,肥胖男生腰围、体脂百分比与通气功能呈负相关;肥胖、超重女生体质指数(BMI)与通气功能呈负相关.结论与对照相比,肥胖、超重青少年通气功能有一定影响,小气道功能差异无统计学意义.肥胖、超重男生瘦体重对通气功能有正性作用,体脂百分比对肥胖男、女青少年通气功能有负性作用.中心性体脂分布模式对男生通气功能有负性影响.     

Characteristics of monozygotic male and female twins discordant for overweight: a descriptive study

OBJECTIVES: BMI is highly heritable. Yet, trends in obesity highlight environmental influences on body weight. Monozygotic (MZ) twins discordant for overweight offer a unique opportunity to examine these factors. METHODS: MZ male (n=8 pairs) and female twins (n=10 pairs) discordant for overweight (defined as the BMI of one twin being at least 24.5, and the BMI of his/her co-twin being below 24.5 and at least three points lower) were identified from the Mid-Atlantic Twin Registry. Variables were assessed via self-report questionnaires. RESULTS: One overweight and two non-overweight females met criteria for bulimia nervosa. Rates of dieting and binge eating were high among all males and females. Hunger scores were higher among non-overweight females; disinhibition scores were higher among overweight males. Only one non-overweight and three overweight males smoked; 90% of non-overweight and 40% of overweight females smoked. CONCLUSIONS: Assessing tobacco use and eating disorders may be important when sampling on the basis of family members who are discordant for BMI. Finally, results suggest possibilities for interventions in individuals at-risk for overweight.     

Body Dissatisfaction,Dietary Restraint,Depression, and Weight Status in Adolescents

BACKGROUND: Adolescence may be a crucial period for developing obesity and associated mental health problems. This study examined the relationship of weight status on body image, eating behavior, and depressive symptoms in youth. METHODS: A survey was conducted on 1490 youth attending grades 7–12. Participants completed questionnaires on body image, eating behavior, and mood and were measured for height and weight to calculate body mass index (BMI). Weight classification was based on the International Obesity Task Force guidelines, whereby youth at or above the 95th BMI percentile for age and sex were classified as obese, those between 85th and 94th BMI percentile as overweight, and those between 5th and 84th BMI percentile as normal weight. Several multivariate analyses of variance (MANOVAs) were conducted to examine these relationships. RESULTS: Clear relationships emerged between body image and weight classification. Obese youth reported higher body dissatisfaction than overweight youth, who reported more body dissatisfaction than normal weight youth. These effects were independent of age and gender. A relationship was also found for dietary restraint and weight status whereby higher restraint scores were associated with greater adiposity. Similarly, obese youth reported greater depressive symptoms, including anhedonia, negative self-esteem, and higher overall depression scores compared with overweight and normal-weight youth. CONCLUSIONS: Psychopathology in obese youth is well known in clinical samples but this study suggests that obese youth in the community may be at increased risk of developing body dissatisfaction, dietary restraint, and depressive symptoms compared with overweight or normal weight youth.     

Weight status and body image perception in Italian children.

BACKGROUND: Previous research suggests there is a tendency in overweight subjects to underestimate their weight status. This study investigated the perception of body image in Italian children, with particular regard to overweight children. METHODS: Primary school children (n = 866) were recruited for this cross-sectional nutritional survey in northern Italy. Anthropometric measurements were performed to determine body mass index (BMI). Body image perception was assessed with the Body Silhouette Chart for preadolescent children shown to the children and to their mothers (n = 778) during an interview. A new scheme to identify wrong (F.1, F.2) or inappropriate (F.3) self figure responses in overweight subjects was used. RESULTS: More than one-third of the Italian children examined were above the normal BMI range (prevalence of overweight: 35.8%, girls; 37.2%, boys). A higher degree of dissatisfaction was expressed by girls than by boys, and the percentage increased in overweight/obese children. A discrepancy between the self figure perception and the real nutritional status of the subject occurred in 6-9% of the overweight/obese children. CONCLUSION: The comparison of body image perception and anthropometric assessment of nutritional status could play an important role in future programs of nutritional surveillance as they provide indications of dissatisfaction and body image disturbances.     

上海保税区企业人群体质指数、腰臀比与血脂异常的关系

目的 探讨上海保税区企业人群体质指数、腰臀比（WHR）与血脂异常的关系。方法 从2006年1月至2007年8月上海外高桥保税区企业员工的体检资料中选取有人体成分、血脂及肝脏超声波检查项目者350名,根据体质指数分为超重肥胖组（177例）及正常组（173例）,比较两组的体质指数、WHR、体脂比率（FAT%）及血脂状况、脂肪肝及血脂异常患病率。结果 超重肥胖组的WHR、FAT%、血清甘油三酯（TG）和胆固醇（TC）的水平明显高于正常组,高密度脂蛋白胆固醇的水平明显低于正常组,两组间的差别均有统计学意义（P=0.000）。超重肥胖组中心性肥胖、脂肪肝和高TG血症、高TC血症、低HDL-C血症的患病率分别为88.70%，72.32%，49.7%33.89%，40.68%，与正常组比较,差别有统计学意义（P=0.000）。结论 通过人体成分测定可以早期识别、早期干预高危人群,对预测和降低心血管疾病的发生有重要意义。     

Body image distortion in fifth and sixth grade students may lead to stress, depression, and undesirable dieting behavior

The widespread pursuit of a thin physique may have a detrimental impact on the wellbeing of preadolescents. The influence of body image distortions on the lifestyles, dieting behaviors, and psychological factors was investigated in 631 fifth and sixth grade children in Kyeonggi-do, Korea. Children were classified into three weight groups (underweight, normal, and overweight) and three perception groups (underestimation, normal, and overestimation). Necessary information was obtained by questionnaire, and each subject''s weight status was determined by the Röhrer index calculated from the annual measurement records, which were obtained from the school. According to their current weights, 57.4% of children were normal and 32.2% were overweight or obese, 16.6% of the children overestimated their body weight, and 55.2% had an undistorted body image. Overweight children had desirable lifestyles and dietary habits and presented reasonable weight control behaviors. Compared to those without distortion, the overestimated group had greater interest in weight control (P = 0.003) and dissatisfaction with their body weights (P = 0.011), presented unhealthy reasons to lose weight (P = 0.026), and had higher scores for "feeling sad when comparing own body with others" (P = 0.000) and for "easily getting annoyed and tired" (P = 0.037), even though they had similar obesity indices. More subjects from the overestimation group (P = 0.006) chose drama/movies as their favorite TV programs, suggesting a possible role for the media in body image distortion. These findings suggest that body image distortion can lead preadolescents to develop stress about obesity and unhealthy dieting practices, despite similar obesity indices to those without distorted body images. These results emphasize the importance of having an undistorted body image.     

分阶段减重模式对超重肥胖女性减重效果的研究

目的 探讨分阶段减重模式对超重肥胖女性减重效果,为临床减重方案提供依据。方法 选取2021年1—6月在青岛市妇女儿童医院营养门诊减重的无器质疾病的超重肥胖女性46例作为研究对象,采用一阶段极低碳水化合物饮食2周,二阶段限能量平衡饮食4周,期间配合有氧、抗阻力运动。监测干预前后减重者体重、形态学指标、体成分指标的变化。数据采用重复测量方差分析进行统计学分析。结果 46例减重者经过两阶段的饮食及运动干预,体重（F = 343.033,P＜0.001）、体质指数（body mass index,BMI）（F = 331.302,P＜0.001）、腰围（F = 124.360,P＜0.001）、臀围（F = 80.558,P＜0.001）、腰臀比（F = 8.325,P = 0.002）、体脂肪（F = 255.959,P＜0.001）、内脏脂肪面积（F = 123.372,P＜0.001）、体脂率（F = 134.714,P＜0.001）均下降,差异具有统计学意义。结论 分阶段减重模式可以明显降低超重肥胖女性的体重,改善体成分,为临床减重提供思路。     

Why does dieting predict weight gain in adolescents? Findings from project EAT-II: a 5-year longitudinal study

OBJECTIVE: Dieting has been found to predict weight gain in adolescents, but reasons for this association remain unclear. This study aimed to explore potential mechanisms by which dieting predicts weight gain over time in adolescents. DESIGN: Population-based, 5-year longitudinal study. PARTICIPANTS: Adolescents (n=2,516) from diverse ethnic and socioeconomic backgrounds who completed Project EAT (Eating Among Teens) surveys in 1999 (Time 1) and 2004 (Time 2). MAIN OUTCOME MEASURE: Body mass index (BMI) change over 5 years. STATISTICAL ANALYSIS: Multiple regressions were used to examine associations between Time 1 dieting and Time 2 binge eating, breakfast consumption, fruit and vegetable intake, and physical activity. Associations were then examined between these behaviors and BMI change. Finally, to test for mediating effects, associations between dieting and BMI change were examined with and without the inclusion of these behaviors, and regression coefficients were compared. RESULTS: In female adolescents, dieting predicted increased binge eating (P<0.001) and decreased breakfast consumption (P=0.030). In male adolescents, dieting predicted increased binge eating (P<0.001), decreased physical activity (P=0.006), and a trend toward decreased breakfast consumption (P=0.064). These behaviors were also associated with increases in BMI. The association between dieting and BMI increase was weakened, but still remained significant, after binge eating, breakfast consumption, fruit/vegetable intake, and physical activity were included in the model being tested. Thus, the longitudinal association between dieting and BMI increase was partially mediated by these behaviors. CONCLUSIONS: In part, dieting may lead to weight gain via the long-term adoption of behavioral patterns that are counterproductive to weight management.     

Overestimation of own body weights in female university students: associations with lifestyles, weight control behaviors and depression

The study aimed to analyze the lifestyles, weight control behavior, dietary habits, and depression of female university students. The subjects were 532 students from 8 universities located in 4 provinces in Korea. According to percent ideal body weight, 33 (6.4%), 181 (34.0%), 283 (53.2%), 22 (4.1%) and 13 (2.5%) were severely underweight, underweight, normal, overweight and obese, respectively, based on self-reported height and weight. As much as 64.1% and only 2.4%, respectively, overestimated and underestimated their body weight status. Six overweight subjects were excluded from overestimation group for the purpose of this study, resulting in overestimation group consisting of only underweight and normal weight subjects. Compared to those from the normal perception group, significantly more subjects from the overestimation group were currently smoking (P = 0.017) and drank more often than once a week (P = 0.015), without any significant differences in dietary habits. Despite similar BMIs, subjects who overestimated their own weight statuses had significantly higher weight dissatisfaction (P = 0.000), obesity stress (P = 0.000), obsession to lose weight (P = 0.007) and depression (P = 0.018). Also, more of them wanted to lose weight (P = 0.000), checked their body weights more often than once a week (P = 0.025) and had dieting experiences using ''reducing meal size'' (P = 0.012), ''reducing snacks'' (P = 0.042) and ''taking prescribed pills'' (P = 0.032), and presented ''for a wider range of clothes selection'' as the reason for weight loss (P = 0.039), although none was actually overweight or obese. Unlike the case with overestimating one''s own weight, being overweight was associated with less drinking (P = 0.035) and exercising more often (P = 0.001) and for longer (P = 0.001) and healthier reasons for weight control (P = 0.002), despite no differences in frequency of weighing and depression. The results showed that weight overestimation, independent of weight status, is associated with risky lifestyles, weight control behaviors, and mental conditions. Preventive interventions should focus not only on obesity, but also on body weight overestimation.     

Anthropometric and psychosocial changes in obese adolescents enrolled in a Weight Management Program

OBJECTIVE: To determine short- and long-term effects of the Bright Bodies Weight Management Program on obese adolescents and to further observe if a diet or nondiet approach is more successful. DESIGN: Twenty-five obese adolescents completed a 1-year, comprehensive weight-management program and returned for a 2-year follow-up. Adolescents were 11 to 16 years old (17 female, eight male) with mixed ethnic backgrounds. Although the program emphasizes a nondiet approach, eight children requested a structured meal plan (diet approach), while 17 were taught to make better food choices (nondiet approach). Body mass index (BMI) z score, body fat percent, and self-concept were measured at 0, 1, and 2 years. Outcomes were analyzed for the entire group and by diet method groups. STATISTICAL ANALYSIS: Changes in outcome variables were evaluated using covariance pattern models for repeated measures. RESULTS: At 1 year, the entire group (N=25) demonstrated a decrease in BMI z score (P <.001) and body fat percent (P <.001), while self-concept scores increased (P <.001). At 2 years, the decrease in BMI z score was still significant (P =.004) and body fat percent and self-concept scores remained improved, although not significant compared to baseline (P =.15 and P =.10, respectively). When comparing dietary approaches, the dieting group (n=8) tended to show favorable results short-term for BMI z score at year 1 (P =.11), but by year 2, the nondieting group (n=17) further improved BMI z score (P =.006), while the dieting group reverted toward baseline. CONCLUSIONS: The Bright Bodies Weight Management Program was successful at decreasing BMI z scores both short and long term. In a separate analysis, dieting showed more superior short-term results, but a nondiet approach demonstrated improved long-term results.     

儿童肥胖对高血压发病率影响的随访研究

目的 探讨儿童肥胖状态及肥胖状态的改变对其高血压发病率的影响.方法 采取前瞻队列研究的方法,抽取2004年北京市儿童青少年代谢综合征队列人群中2189名6～16岁血压正常儿童,于2010年12月对其随访,进行身高、腰围(WC)、体重和血压的测量.分别以体质指数(BMI)和WC作为评价超重、肥胖、腹型肥胖的指标.以不同肥胖状态组设置哑变量,以随访时点是否高血压作为结局变量,进行非条件logistic回归分析,分析基线肥胖状态及肥胖状态的改变与高血压发病率之间的关系,并计算相应的OR值及95%CI值.结果 共完成了1184名在校学生的随访,6年间高血压累积发病率为19.9%(236/1184).男性高血压发病率(23.2%,149/643)高于女性(16.1%,87/541) (χ2=9.257,P=0.002).基线非超重组、超重组、肥胖组随访期间高血压累积发病率分别为8.7%(45/519)、19.3%(35/181)、32.4%(156/484)(χ2=9.332,P<0.001),基线非肥胖组与腹型肥胖组随访期间高血压累积发病率分别为10.3%(63/613)、30.7%(173/567) (χ2=77.753,P<0.001).基线肥胖组的高血压发病危险高于基线非超重组(BMI:OR=4.9,95%CI:3.4～7.0)和基线非肥胖组(WC:OR=3.9,95%CI:2.8～5.3);基线时BMI、WC水平相同时,随访时BMI、WC水平增加,高血压发病危险增加.控制年龄、性别,基线BMI和WC每增加1 kg/m2和1 cm,高血压发病风险分别增加0.21和0.07倍,OR(95%CI)值分别为1.21(1.16～1.26)和1.07(1.05～1.09);随访时BMI和WC改变量每增加1 kg/m2和1 cm,高血压发病风险分别增加0.16和0.05倍,OR(95%CI)值分别为1.16(1.11～1.22) 和1.05(1.03～1.07).结论 儿童肥胖及肥胖水平升高的改变会增加其高血压发病风险.

Abstract：

Objective To explore the impact of obesity level and the level change in childhood on hypertension incidence.Methods A perspective cohort study was conducted.As part of Beijing Child and Adolescent Metabolic Syndrome Study,2189 aged 6-16 year non-hypertensive children was followed up in December,2010.In this study,height,weight,waist circumference (WC) and blood pressure was measured at follow-up,and body mass index (BMI) and WC was respectively used to assess overweight,obesity and abdominal obesity.Non-conditional logistic regression was used to evaluate the association between baseline obesity status, change of obesity status and hypertension incidence. OR and 95%CI were computed in the model using obese status as dummy variable and hypertension at follow up visit as dependent variable.Results The total hypertension incidence of 1184 subjects during 6 years follow-up was 19.9%(236/1184).The hypertension incidence in male (23.2%,149/643) was higher than that in female (16.1%,87/541) (χ2=9.257,P=0.002).The hypertension incidence of non-overweight,overweight and obese children at baseline was 8.7%(45/519),19.3%(35/181) and 32.4%(156/484)respectively (χ2=9.332,P<0.001),and the incidence of non-obese and abdominal obese children at baseline was respectively 10.3%(63/613) and 30.7%(173/567) (χ2=77.753,P<0.001).Hypertension incidence in the baseline obesity group was higher than the non-overweight (BMI:OR=4.9,95%CI:3.4-7.0) and non-obese group (WC:OR=3.9,95%CI: 2.8-5.3).The hypertension incidence increased with the follow-up BMI/WC level,based on the same baseline level of BMI and WC.The hypertension risk increased to 0.21 and 0.07 times respectively with elevation of baseline BMI level by 1 kg/m2 and WC level by 1 cm,and OR(95%CI) were 1.21(1.16-1.26) and 1.07(1.05-1.09),respectively.Similarly,the hypertension risk increased 0.16 and 0.05 times respectively with the elevation of BMI level change by 1 kg/m2 and 1 cm,and OR (95%CI) were 1.16(1.11-1.22) and 1.05(1.03-1.07),respectively.Conclusion Obesity and increased obesity level change in childhood can increase the risk of incident hypertension.     

Body mass index and waist circumference both contribute to differences in insulin-mediated glucose disposal in nondiabetic adults

BACKGROUND: Overweight and obese individuals are more likely to be insulin resistant and at increased risk of adverse clinical outcomes. Questions remain as to whether waist circumference (WC) or body mass index (BMI) most effectively identifies insulin-resistant individuals. OBJECTIVE: This study quantified insulin-mediated glucose uptake (IMGU) in 330 apparently healthy volunteers and compared the relation between this value and measurements of WC and BMI. DESIGN: IMGU was quantified via determination of the steady-state plasma glucose (SSPG) concentration during the insulin-suppression test. Differences in SSPG concentrations due to variations in WC within a given BMI category, as well as those due to differences in BMI within a given WC classification, were then compared. RESULTS: BMI and WC correlated with each other (r = 0.78, P < 0.001) and equally with SSPG concentrations (r = 0.58 and 0.57, respectively; P < 0.001). When stratified by BMI, abdominally obese subjects within the overweight BMI category had higher SSPG concentrations than did those with a normal WC (P < 0.05). When classified by WC, subjects in the overweight BMI category had greater SSPG concentrations than did subjects in the normal BMI category within the normal WC category (P < 0.01), as did subjects in the obese BMI category in comparison with subjects in the overweight BMI category within the obese WC category (P < 0.01). CONCLUSIONS: The more overweight or obese a person, the greater the degree of insulin resistance; differences in adiposity accounted for approximately one-third of the variation in IMGU, irrespective of the index used. Furthermore, there was no difference in the relation between the degree of insulin resistance and either index of adiposity.     

Body image and body satisfaction play important roles in the path to dieting behavior in Japanese preadolescents: The Toyama birth cohort study

Objectives To analyze the path to dieting behavior in Japanese preadolescents. Methods A cross-sectional study of dieting behavior among 5,244 preadolescents (2,452 boys and 2,792 girls aged 12–13) born in Toyama prefecture. Results While increasing with body mass index (BMI), the percentage of those who had tried dieting was higher in those who perceived themselves fat than in those who perceived themselves thin or average. Of those who wanted to be thinner, 16.1% of boys and 26.8% of girls had tried dieting. Path analysis in nonobese subjects (2,116 boys and 2,334 girls) showed that (1) body image was primarily based on BMI, (2) body image led to body dissatisfaction, and (3) body dissatisfaction led to dieting behavior. Pubertal changes had a significant effect on body image (path coefficient <0)for boys and body satisfaction (path coefficient >0) for girls, in addition to that on BMI. Maternal BMI had a significant effect on BMI but not on body image, body satisfaction, or dieting behavior. Conclusions Body image and body satisfaction play important roles in the path to dieting behavior in Japanese preadolescents. Pubertal changes may reinforce dieting behavior, but the mechanism may differ by sex.     

Young teenagers' perceptions of their own and others' bodies: a qualitative study of obese, overweight and 'normal' weight young people in Scotland

The rise in numbers of overweight/obese children in the UK is causing widespread concern. Biomedical constructions of body acceptability and 'good health' mean that overweight/obese young people are frequently seen as deviant. The socio-cultural contexts within which young teenagers become fat, and lay conceptualisations of fatness, have largely been ignored. This qualitative study involved in-depth interviews with teenagers aged 13-14 years (n = 36), drawn from families living in areas classified as socio-economically disadvantaged. Half of the sample had a Body Mass Index (BMI) classifying them as overweight or obese, whilst the remainder were classified as being 'normal' weight. Participants' embodied perceptions of fatness were complex and sometimes contradictory. We discuss what young teenagers perceive the influences on fatness and body size to be; the professed consequences of being fat; participants' experiences of attempting to lose weight; and, their reported interactions with friends and family relating to fatness and dieting. Participants rarely mentioned any health-related consequences of their own and others' fatness, although wearing 'nice' clothes and being slowed down were raised as considerations by girls and boys, respectively. 'Normal' weight teenagers who disliked their bodies or who wanted to lose weight often claimed to be anxious about this. Being very obese also led to anxiety and reported attempts at 'crash dieting'. Acceptance of body size/shape was, however, common amongst the overweight and obese teenagers, although some had attempted weight loss. The teenagers in this study were rarely supportive of friends or family who attempted to lose weight and frequently disagreed with others' perceptions of fatness. These findings are important as they contradict the common perception that being overweight/obese is related to body dissatisfaction and that young people have a fear of fatness.     

Usefulness of different techniques for measuring body composition changes during weight loss in overweight and obese women

The objective was to compare measures from dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and anthropometry with a reference four-compartment model to estimate fat mass (FM) and fat-free mass (FFM) changes in overweight and obese women after a weight-loss programme. Forty-eight women (age 39.8 +/- 5.8 years; weight 79.2 +/- 11.8 kg; BMI 30.7 +/- 3.6 kg/m2) were studied in an out-patient weight-loss programme, before and after the 16-month intervention. Women attended weekly meetings for the first 4 months, followed by monthly meetings from 4 to 12 months. Body composition variables were measured by the following techniques: DXA, anthropometry (waist circumference-based model; Antrform), BIA using Tanita (TBF-310) and Omron (BF300) and a reference four-compartment model. Body weight decreased significantly ( - 3.3 (sd 3.1) kg) across the intervention. At baseline and after the intervention, FM, percentage FM and FFM assessed by Antrform, Tanita, BF300 and DXA differed significantly from the reference method (P < or = 0.001), with the exception of FFM assessed by Tanita (baseline P = 0.071 and after P = 0.007). DXA significantly overestimated the change in FM and percentage FM across weight loss ( - 4.5 v. - 3.3 kg; P 0.05) from the reference model in any body composition variables. We conclude that these methods are widely used in clinical settings, but should not be applied interchangeably to detect changes in body composition. Furthermore, the several clinical methods were not accurate enough for tracking body composition changes in overweight and obese premenopausal women after a weight-loss programme.