Eating behaviors and indexes of body composition in men and women from the Québec family study

OBJECTIVE: To put into relationship the dietary and anthropometric profile of men and women with their eating behaviors (cognitive dietary restraint, disinhibition, and susceptibility to hunger) and to assess whether gender and obesity status influence these associations. RESEARCH METHODS AND PROCEDURES: Anthropometric measurements (including visceral adipose tissue accumulation), dietary profile (3-day food record), and eating behaviors (Three-Factor Eating Questionnaire) were determined in a sample of 244 men and 352 women. RESULTS: Women had significantly higher cognitive dietary restraint and disinhibition scores than men (p < 0.0001). In both genders, scores for disinhibition and susceptibility to hunger, but not for cognitive dietary restraint, were higher in obese subjects than in overweight and nonobese subjects (p < 0.05). Positive correlations were observed between rigid restraint and most of the anthropometric variables studied (0.12 相似文献   

儿童人格特征和饮食行为与肥胖的相关性

  目的  探讨饮食行为在人格特征与儿童肥胖关联中的作用, 为有效预防中国儿童肥胖提供科学依据。  方法  2018年9月在北京、山西长治、新疆乌鲁木齐3个地区调查1 271名小学四年级儿童。采用大五人格量表简表测量人格特征, 使用儿童饮食行为问卷测量儿童饮食行为, 通过体格检查获取5个肥胖相关指标。  结果  校正性别、年龄和地区后, 严谨性人格标准化评分与儿童BMI(B=-0.227, 95%CI=-0.422~-0.031)、BMI Z评分(B=-0.081, 95%CI=-0.158~-0.006)、腰围(B=-0.720, 95%CI=-1.281~-0.159)、腰臀围比(B=-0.004, 95%CI=-0.007~ -0.001)和体脂百分比(B=-0.727, 95%CI=-1.293~-0.162)均呈负相关(P值均 < 0.05)。中介作用分析结果显示, 严谨性人格可能通过食物响应和情绪性过食行为影响BMI、BMI Z评分、腰围、腰臀围比和体脂百分比; 食物响应和情绪性过食行为在严谨性人格与5个肥胖相关指标的中介作用占总效应的比例分别为27.5%~47.1%和0.9%~18.0%(P值均 < 0.05)。  结论  严谨性人格与较低的儿童肥胖风险相关, 食物响应和情绪性过食行为是两者关联的中介因素。应针对严谨性较低的儿童及时开展健康教育, 以早期预防肥胖的发生。     

Lack of relationship between calcium intake and body size in an obesity-prone population

OBJECTIVE: Dietary calcium intake, especially from dairy products, may have a protective effect against obesity. This study aimed to determine if calcium intake is associated with body weight and adiposity in Pima Indians, an obesity-prone population. RESEARCH METHODS AND PROCEDURES: Subjects were 65 Pima Indian adults (35 men/30 women, age 33+/-8 years [mean+/-standard deviation]) participating in a study of eating behavior and 78 Pima Indian children (36 boys/42 girls, age 10.4+/-0.3 years) participating in a study of childhood obesity. Height and weight were measured, and body composition was determined by dual-energy x-ray absorptiometry. Food intake in adults was assessed using the Block 1998 Food Questionnaire; food intake in children was assessed using a 24-hour recall with parental assistance. RESULTS: In adults, mean energy intake was 3,163+/-1,037 kcal/day, mean percentage of energy from fat was 41%+/-7%, and calcium intake was 914+/-333 mg/day. In children, mean energy intake was 1,988+/-733 kcal/day, mean percentage of energy from fat was 36%+/-9%, and calcium intake was 637+/-352 mg/day, half the recommended daily intake for this age group. There were no significant associations between calcium intake and body weight (r=0.05, P=.71; r=0.04, P=.73), body fat (r=0.16, P=.19; r=0.12, P=.42), or body mass index (r=0.01, P=.97; r=0.04, P=.77) in either adults or children, respectively. DISCUSSION: One explanation for the lack of association between reported calcium intake and body size in Pima Indians may be that the high-fat, high-energy diet consumed by the population overwhelmed the "anti-obesigenic" effect of calcium. CONCLUSIONS: We were unable to find an association between calcium intake and body size or adiposity in Pima Indian adults and children. Although the essentiality of calcium to bone health is well established, the role of calcium and dairy product intake in obesity and weight management remains uncertain.     

Eating behavior in the Old Order Amish: heritability analysis and a genome-wide linkage analysis

BACKGROUND: Eating behavior and thus dietary intake affect the development of obesity-related diseases such as diabetes, hypertension, and hyperlipidemia. OBJECTIVE: We investigated the genetic underpinnings of eating behavior. DESIGN: We administered a standardized eating behavior inventory to 624 adults from 28 families participating in the Amish Family Diabetes Study. Three quantifiable components of eating behavior were measured: restraint, disinhibition, and hunger. Associations between eating behavior scores and physical characteristics were evaluated. Heritability analysis and a genome-wide multipoint linkage analysis were performed. RESULTS: Eating behavior scores were associated with obesity and obesity-related phenotypes. Heritability estimates were 0.28 +/- 0.09 for restraint, 0.40 +/- 0.10 for disinhibition, and 0.23 +/- 0.09 for hunger (P < 0.001). The linkage analysis showed 4 regions of suggestive linkage. We observed suggestive evidence for linkage of restraint scores to 2 chromosomal regions, near markers D3S1304 [LOD (log of odds) = 2.5, P = 0.0003] and D6S276 (LOD = 2.3, P = 0.0006). We previously reported that D3S1304 is linked to a locus influencing percentage body fat in this same population (LOD = 1.6), suggesting that this behavioral phenotype may be secondary to obesity. The maximum LOD scores for disinhibition were 1.6 (P = 0.003) near marker D7S657 and 1.4 (P = 0.005) near marker D16S752. The maximum LOD score for hunger was 1.4 (P = 0.005) near marker D3S1278. CONCLUSION: Significant familial effects on eating behavior and suggestive genetic linkage were found in Amish adults.     

Links between mothers' and children's disinhibited eating and children's adiposity

Few studies have examined relationships between parents' and children's specific disinhibited eating behaviors. We investigated links among mothers' and children's binge/loss of control eating, eating in the absence of hunger, and children's adiposity in 305 non-treatment-seeking youth, aged 8-17 years (13.62±2.65 years; 49.8% female) and their mothers. Youths' loss of control eating and eating in the absence of hunger were assessed by interview and self-report questionnaire. Children's adiposity was assessed with BMI-z and air displacement plethysmography. Maternal binge eating, eating in the absence of hunger and highest, non-pregnant BMI were self-reported. In structural equation models controlling for mothers' BMI, mothers' binge eating related to children's loss of control eating, and mothers' eating in the absence of hunger related to children's eating in the absence of hunger. Mothers' binge eating and children's eating in the absence of hunger were unrelated, as were mothers' eating in the absence of hunger and children's loss of control. Further, mothers' binge eating was indirectly related to children's adiposity through children's loss of control eating. Likewise, mothers' eating in the absence of hunger indirectly related to children's adiposity through children's eating in the absence of hunger. Mothers and children share similar, specific disinhibited eating styles.     

486名3～6岁儿童体重指数与饮食行为的相关分析

目的 了解3～6岁儿童体重指数和饮食行为,并分析两者之间的关系,为儿童营养不良的防治措施提供参考依据。方法 2017年9月-2018年1月,采用分层整群抽样的调查方法,对所选取的486名3～6岁儿童的主要看护人进行调查,填写学龄前儿童饮食行为量表。调查员测量儿童身高、体重,计算体重指数。采用χ²检验、独立样本t 检验、单因素方差分析和多因素非条件Logistic回归分析对数据进行统计分析。结果 调查发现,在486名儿童中,体重指数正常儿童356名、消瘦11名、超重61名、肥胖58名,检出率分别为73.25%、2.26%、12.55%和11.93%。3～6岁儿童不同性别饮食行为各维度得分的差异无统计学意义(P>0.05),不同年龄组情绪性饮食(F=3.472,P=0.032)、主动进食能力得分(F=3.816,P=0.023)差异有统计学意义。不同体重指数组儿童在挑食(F=4.804,P=0.003)、不良进食习惯(F=6.077,P<0.001)及过饱响应维度得分(F=4.392,P=0.005)差异有统计学意义。儿童体重指数的影响因素有挑食(OR=-0.367,95%CI:-0.966~-0.112,P<0.001)、不良饮食习惯(OR=-0.097,95%CI:-20.705~-0.204,P=0.045)。结论 该地区3～6岁儿童存在肥胖、消瘦等营养不良问题;挑食、不良进食习惯影响儿童体重指数;不同体重指数组儿童饮食行为在挑食、不良进食习惯及过饱响应方面有所不同。     

Height and adiposity among children

OBJECTIVE: Although BMI (kilograms per meter squared) is widely used as a surrogate measure of adiposity, it is moderately associated (r approximately 0.3) with height among children. We examined whether the resulting preferential classification of taller children as overweight, based on a BMI > or = 95th percentile, is appropriate. RESEARCH METHODS AND PROCEDURES: We assessed the cross-sectional relation of height among 5- to 18-year-old subjects (n = 1180) to levels of BMI, the sum of 10 skinfold thicknesses, and percentage body fat as determined by DXA. RESULTS: The prevalence of a BMI level > or = 95th percentile was substantially higher among 5- to 11-year-old subjects who were relatively tall for their age than among shorter children. Among 5- to 8-year-old boys, for example, each SD increase in height-for-age was associated with a 4.6-fold increase in the prevalence of overweight (p < 0.001). Height not only was associated with BMI but also showed similar correlations with the skinfold sum and with percentage body fat; furthermore, the magnitudes of these associations decreased with age. We also found that the association between percentage body fat and BMI (r = 0.85 to 0.90) was close to the maximum correlation that can be achieved by any weight-height index. DISCUSSION: The use of BMI, which preferentially classifies taller young children as overweight, is appropriate because height and adiposity are correlated before the age of 12 years.     

Short-term predictors of abdominal obesity in children

BACKGROUND: The aim of this study was to examine the short-term tracking of abdominal adiposity in children. METHODS: A total of 918 children (477 boys) aged 6-12 years at baseline were followed-up for 2 years. Central obesity was assessed by waist circumference (WaistC), whereas body fat distribution by waist-to-hip ratio. Maturity was assessed by the Khamis-Roche method. Parental fatness and children's cardiorespiratory fitness (CRF) were also evaluated. Multiple and logistic regressions were employed to identify the predictors of BMI and WaistC. RESULTS: Tracking of body fatness and body fat distribution was high (r = 0.69-0.86, P < 0.01). More boys remained obese than girls (P < 0.05), whereas a greater percentage of boys moved to a higher quartile of WaistC after the 2-year follow-up (22.0 vs 14.1%, P < 0.01). Sex, child's maturity and WaistC at baseline, CRF, and maternal BMI explained 76% of the variability in BMI and WaistC at the follow-up (n = 290). Children with high WaistC at baseline and low CRF presented 1.9- and 4.3-fold increased risk of remaining in the upper quartile of WaistC at the follow-up (P < 0.01; n = 552). CONCLUSION: Youth with increased WaistC at baseline and low CRF presented an increased chance of maintaining central obesity at the follow-up. More boys than girls moved into a higher quartile of abdominal obesity during the 2-year follow-up period and this should be taken into account in designing programmes for childhood obesity.     

Is restrained eating a risk factor for weight gain in a general population?

BACKGROUND: In modern societies characterized by abundant and accessible foods, restrained eating may become an adaptive behavior to limit weight gain. OBJECTIVE: We assessed the relations between eating behavior (EB) and adiposity in a general population over a 2-y period. DESIGN: We recruited 466 adults and 271 adolescents in 1999 on a geographical basis to participate in a longitudinal study. At the initial examination and 2 y later, they answered an EB questionnaire, the Three-Factor Eating Questionnaire-R18, which measured cognitive restraint (CR), uncontrolled eating, and emotional eating. On the same occasions, several measures of adiposity were also obtained: body mass index (BMI; in kg/m2), waist circumference, the sum of 4 skinfold thicknesses, and percentage body fat. Relations between EB and adiposity were tested separately in adults and adolescents by using mixed linear regressions after adjustment for age, sex, and (in adolescents) Tanner pubertal stage. RESULTS: At baseline, CR was positively associated with BMI in normal-weight subjects (mean BMI: 21.4 in the lowest to 23.3 in the highest CR quintile; P < 0.001) but not in overweight adults (P = 0.25). Initial CR did not predict change in adiposity variables (BMI change: P = 0.79 in adults, P = 0.57 in adolescents and young adults). Conversely, a high initial BMI was associated with a larger increase in CR (beta = 20.1, P < 0.0001 in adults; beta = 21.7, P = 0.003 in adolescents and young adults). CONCLUSIONS: Restrained eating is strongly associated with adiposity in normal-weight subjects but not in overweight subjects. However, restrained eating does not promote weight gain.     

Visceral abdominal fat is correlated with whole-body fat and physical activity among 8-y-old children at risk of obesity

BACKGROUND: Abdominal fat is more related to health risk than is whole-body fat. Determining the factors related to children's visceral fat could result in interventions to improve child health. OBJECTIVE: Given the effects of physical activity on adults' visceral fat, it was hypothesized that, after accounting for whole-body fat, physical activity would be inversely related to children's visceral (VAT), but not to subcutaneous (SAT), abdominal adipose tissue. DESIGN: In this cross-sectional observational study conducted in forty-two 8-y-old children (21 boys, 21 girls) at risk of obesity [>75th body mass index (BMI) percentile, with at least one overweight parent], familial factors (eg, maternal BMI), historic weight-related factors (eg, birth weight), and the children's current physical activity (self-reported and measured with accelerometry) and diet were examined as potential correlates of the children's whole-body composition (measured with BMI and dual-energy X-ray absorptiometry) and abdominal fat distribution (measured by magnetic resonance imaging). RESULTS: Accelerometer-measured physical activity was related to whole-body fat (r = -0.32, P < 0.10), SAT (r = -0.29, P < 0.10), and VAT (r = -0.43, P < 0.05). In regression models, whole-body fat was positively associated with and the only significant correlate of SAT. Whole-body fat was positively related and accelerometer-measured physical activity was negatively and independently related to the children's VAT. CONCLUSIONS: Both SAT and VAT in 8-y-old children at risk of obesity are most closely associated with whole-body fat. However, after control for whole-body fat, greater physical activity is only associated with lower VAT, not SAT, in these children.     

Like mother, like daughter: familial patterns of overweight are mediated by mothers' dietary disinhibition

BACKGROUND: Obese parents are more likely to have obese children. Parents provide both the genes and eating environment for their children and familial patterns of adiposity are the result of gene-environment interactions. Environmental factors are implicated in the rapid increases in prevalence of childhood overweight that have occurred in the past 2 decades. Examination of aspects of the family environment may provide insight into increases in childhood overweight over time. OBJECTIVE: We examined parental characteristics associated with overweight and eating behaviors in preschool children. DESIGN: Seventy-five preschool children and their parents were recruited from local daycare centers. Information was obtained on parents' body mass indexes (BMIs), dietary restraint, and dietary disinhibition. A behavioral index of disinhibited eating in children was used to measure children's eating when given free access to palatable snack foods in the absence of hunger. Children's weight-for-height values were also calculated. RESULTS: Maternal dietary disinhibition (R2 = 0.35, P < 0.01) and maternal BMI (R2 = 0.19, P < 0.05) positively predicted daughters' overweight. Maternal disinhibition (R2 = 0.35, P < 0.05) mediated the relation between mothers' BMI and daughters' overweight when both maternal disinhibition and maternal BMI were used to predict daughters' overweight. Furthermore, when both mothers' disinhibition and daughters' free access intakes were used to predict daughters' overweight, mothers' disinhibition (P < 0.05) showed independent prediction. CONCLUSIONS: These findings suggest that familial influences on child overweight differ according to parent and child sex. Also, these results suggest that mothers' dietary disinhibition mediates familial similarities in degree of overweight for mothers and daughters.     

Serum leptin level among non-obese students: relationship to body fat, blood pressure, serum lipids, physical activity, and eating habits]

Leptin, a product of the ob gene, is thought to play a key role in the regulation of adiposity. However, it is unclear in humans as to whether or not leptin influences the blood pressure, serum lipids, physical activity level, or eating behavior in relation to obesity. Recent reports have indicated both gender-based differences in the leptin levels and a correlation of the percentage of body fat with leptin levels has been observed among obese subjects. As far as we know, these relationships among non-obese young adults have yet to be studied. Therefore, the serum leptin concentrations among 107 non-obese students (72 males and 35 females) were measured by a radioimmunoassay(RIA). Fasting leptin levels ranging between 1.2 and 23.4 ng/mL were observed in all subjects, and the levels among females were 2.6 times higher than in males (7.64 vs 2.95 ng/mL; p < 0.001). A close correlation was observed regarding the log-transformed leptin levels with the percentage of body fat as determined by the bioelectrical impedance analysis method(r = 0.734, p < 0.001 in males and r = 0.579, p < 0.001 in females). In conclusion, these data thus suggest the serum leptin levels among non-obese students show significant gender-based differences while, in addition, the leptin levels also correlate positively with the percentage of body fat. However, it remains unclear as to whether or not the leptin levels are independently related to the blood pressure, serum lipids, physical activity level (sports activity and leisure-time activity), and eating behavior (eating breakfast, mid-day snacking and nighttime snacking).     

青春前期儿童睡眠时间与体脂指标的相关性研究

【目的】 研究上海青春前期儿童睡眠时间与体脂指标的相关性,为改善儿童睡眠质量与肥胖的发展提供依据。 【方法】 采用分层整群随机抽样方法,抽取上海市10所小学的五年级学生1 588名进行社会经济状况、睡眠问卷调查以及体格测量,测量指标包括身高、体重、腰围、臀围以及皮下脂肪等,并进一步计算体质指数(body mass index,BMI)及BMI和腰围的Z值,腰围/身高比和体脂百分比。被选儿童中,男童的比例为52.08%(827名),年龄(10.82±0.39)(9.42~14.08)岁。 【结果】 肥胖的发生率为11.9% (男生15.0%,女生 8.5%,P<0.001)。在校正了肥胖的高危因素后,与睡眠时间≥10 h的儿童相比,睡眠时间不足9 h的儿童有显著较高的BMI、BMI Z值,腰围,腰围Z值,腰围/身高比及体脂百分比(P<0.05)。 【结论】 青春前期儿童睡眠时间不足与体脂指标显著相关。采取措施改善儿童的睡眠状况可能有助于遏止肥胖迅速发展。     

Appetite and adiposity in children: evidence for a behavioral susceptibility theory of obesity

BACKGROUND: Pressures from the "obesogenic" environment are driving up obesity rates, but adiposity still varies widely within the population. Appetitive characteristics could underlie differences in susceptibility to the environment. OBJECTIVE: We examined associations between adiposity and 2 appetitive traits: satiety responsiveness and food cue responsiveness in children. DESIGN: Parents of 2 groups of children, 8-11-y-olds (n = 10 364) from a population-based twin cohort and 3-5-y-olds (n = 572) from a community sample, completed the Child Eating Behavior Questionnaire. Adiposity was indexed with body mass index (BMI; in kg/m(2)) SD scores. For the 8-11-y-olds, waist circumference was also recorded and used to derive waist SD scores. RESULTS: In both samples, higher BMI SD scores were associated with lower satiety responsiveness (8-11-y-olds: r = -0.22; 3-5-y-olds: r = -0.19; P <0.001) and higher food cue responsiveness (r = 0.18 and 0.18; P <0.001). In the twin sample, waist SD scores were associated with satiety responsiveness (r = -0.23, P < 0.001) and food cue responsiveness (r = 0.20, P < 0.001). By analyzing the data by weight categories, children in higher weight and waist categories had lower satiety responsiveness and higher responsiveness to food cues in both samples (8-11-y-olds: both P < 0.001; 3-5-y-olds: both P < 0.05), but the effect was more strongly linear in the older children. All associations remained significant, controlling for child age and sex and parental education and BMI. CONCLUSIONS: Associations between appetite and adiposity are consistent with a behavioral susceptibility model of obesity. Assessing appetite in childhood could help identify higher-risk children while they are still at a healthy weight, enabling targeted interventions to prevent obesity.     

Detection of overweight and obesity in a national sample of 6-12-y-old Swiss children: accuracy and validity of reference values for body mass index from the US Centers for Disease Control and Prevention and the International Obesity Task Force

BACKGROUND: For defining overweight in children, reference values for body mass index (BMI) are available from the US Centers for Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF). However, these 2 sets of reference criteria differ, and their accuracy in classifying adiposity has not yet been validated in most countries. OBJECTIVE: We compared BMI criteria from the IOTF and the CDC with percentage of body fat (%BF) from multisite skinfold thicknesses (SFTs) for identification of overweight in 6-12-y-old Swiss children. DESIGN: In a representative sample (n = 2431), weight, height, and 4 SFTs were measured. Regression and receiver operating characteristic (ROC) curves were used to evaluate BMI as an indicator of adiposity. RESULTS: BMI and %BF were well correlated (r(2) = 0.74), and the areas under the ROC curves for overweight and obesity were 0.956-0.992. The sensitivity and specificity of the IOTF and CDC overweight criteria and of the CDC obesity criteria were high. The sensitivity of the IOTF obesity criteria was only 48% and 62% in boys and girls, respectively. Overall, the performance of the CDC criteria was superior. With the use of the CDC criteria, the prevalence of overweight in girls and boys was 19.1% and 20.3%, respectively. CONCLUSIONS: BMI is an excellent proxy measure of adiposity in 6-12-y-old children. In Swiss children, both BMI criteria accurately predict overweight, but the sensitivity of the IOTF obesity criteria is poor. They failed to detect one-half of the children identified as obese on the basis of %BF from SFTs.     

Impact of parental BMI on the manifestation of overweight 5–7 year old children

Summary Background There is an increase in the prevalence of overweight and obese children. Genetic and environmental factors are contributing factors but the influence of parental nutritional state on early manifestation of overweight is not well characterised. Aim of the study To systematically investigate the impact of parental BMI on the manifestation of overweight in 5 to 7 year old children. Methods Cross-sectional study (as a part of the Kiel Obesity Prevention Study [KOPS]) of 3306 children aged 5–7 years and their parents. The nutritional state of the children (BMI, triceps skinfold, fat mass, prevalence of overweight) was investigated in subgroups differing with respect to parental BMI. Results BMI of the children was significantly correlated with parental BMI (r = 0.272, p < 0.01). Children's BMI showed closer associations with maternal than with paternal BMI (r = 0.254 vs. 0.159, p < 0.01). A multivariate regression analysis showed that parental BMI explained 7.6 % of the variance in children's BMI. OR for overweight was elevated in children with at least one overweight parent (overweight mother: OR 2.9 (boys)/3.1 (girls); overweight father: OR 1.8 (boys)/2.4 (girls). OR was highest for children with two obese parents (OR 7.6 (boys)/6.3 (girls). Children with one obese parent were more frequently overweight than children with one overweight parent. Conclusions Parental BMI showed only a weak correlation with the BMI of their children. However, children's risk of becoming overweight increased with parental overweight and obesity. Thus, familial disposition has to be taken into account to identify risk groups for preventive measures. Received: 5 February 2002, Accepted: 2 May 2002     

广州市不同年龄儿童青少年体脂含量检测结果分析

目的了解不同年龄儿童青少年体脂情况,为制定我国儿童青少年肥胖诊断标准提供依据。方法选定广州市本地生源为主的中、小学各1所,采用生物电阻抗法(BIA)对1305名7~18岁儿童青少年进行体脂含量测定。结果男生体脂百分比(BF%)7岁组为13.2%,8~18岁基本稳定在15%左右,没有随年龄而上升;女生BF%7岁组较低,为12.2%,以后逐渐升高,在10~11岁与男生形成交叉并超越男生。男女生的BF%与BMI相关分析r值分别为0.722和0.954,P值均小于0.001。结论BF%可作为儿童青少年的肥胖诊断标准,但在不同性别和年龄中变化较大,应根据我国人种特点进行大样本的基础调查。     

Assessing body composition among 3- to 8-year-old children: anthropometry, BIA, and DXA

OBJECTIVE: To examine the inter-relationships of body composition variables derived from simple anthropometry [BMI and skinfolds (SFs)], bioelectrical impedance analysis (BIA), and dual energy x-ray (DXA) in young children. RESEARCH METHODS AND PROCEDURES: Seventy-five children (41 girls, 34 boys) 3 to 8 years of age were assessed for body composition by the following methods: BMI, SF thickness, BIA, and DXA. DXA served as the criterion measure. Predicted percentage body fat (%BF), fat-free mass (FFM; kilograms), and fat mass (FM; kilograms) were derived from SF equations [Slaughter (SL)1 and SL2, Deurenberg (D) and Dezenberg] and BIA. Indices of truncal fatness were also determined from anthropometry. RESULTS: Repeated measures ANOVA showed significant differences among the methods for %BF, FFM, and FM. All methods, except the D equation (p = 0.08), significantly underestimated measured %BF (p < 0.05). In general, correlations between the BMI and estimated %BF were moderate (r = 0.61 to 0.75). Estimated %BF from the SL2 also showed a high correlation with DXA %BF (r = 0.82). In contrast, estimated %BF derived from SFs showed a low correlation with estimated %BF derived from BIA (r = 0.38); likewise, the correlation between DXA %BF and BIA %BF was low (r = 0.30). Correlations among indicators of truncal fatness ranged from 0.43 to 0.98. DISCUSSION: The results suggest that BIA has limited utility in estimating body composition, whereas BMI and SFs seem to be more useful in estimating body composition during the adiposity rebound. However, all methods significantly underestimated body fatness as determined by DXA, and, overall, the various methods and prediction equations are not interchangeable.     

Circulating interleukin-6 in relation to adiposity, insulin action, and insulin secretion.

OBJECTIVE: Plasma concentrations of interleukin-6 (IL-6), a proinflammatory cytokine produced and released in part by adipose tissue, are elevated in people with obesity and type 2 diabetes. Because recent studies suggest that markers of inflammation predict the development of type 2 diabetes, we examined whether circulating plasma IL-6 concentrations were related to direct measures of insulin resistance and insulin secretory dysfunction in Pima Indians, a population with high rates of obesity and type 2 diabetes. RESEARCH METHODS AND PROCEDURES: Fasting plasma IL-6 concentrations (enzyme-linked immunosorbent assay), body composition (DXA), insulin action (M; hyperinsulinemic euglycemic clamp), and acute insulin secretory responses to glucose (25 g intravenous glucose tolerance test) were measured in 58 Pima Indians without diabetes (24 women, 34 men). RESULTS: Fasting plasma IL-6 concentrations were positively correlated with percentage of body fat (r = 0.26, p = 0.049) and negatively correlated with M (r = -0.28, p = 0.031), but were not related to acute insulin response (r = 0.13, p = 0.339). After adjusting for percentage of body fat, plasma IL-6 was not related to M (partial r = -0.23, p = 0.089). DISCUSSION: Fasting plasma IL-6 concentrations are positively related to adiposity and negatively related to insulin action in Pima Indians. The relationship between IL-6 and insulin action seems to be mediated through adiposity.