The Association of Restrained Eating With Weight Change Over Time in a Community‐Based Sample of Twins

We investigated the association of restrained eating with BMI and weight gain while controlling for the influence of genes and shared environment. Participants were 1,587 twins enrolled in the University of Washington Twin Registry (UWTR). Restrained eating was assessed by the Herman and Polivy Restraint Scale. Height and weight were self‐reported on two occasions. Analyses used generalized estimating equations or multiple linear regression techniques. Restraint Scale scores were positively associated with both BMI (adjusted β = 0.39 kg/m²; 95% confidence interval (CI) = 0.34–0.44; P < 0.001) and weight gain (adjusted β = 0.33 pounds; 95% CI = 0.17–0.49; P < 0.001). High Restraint Scale scorers had an adjusted mean BMI of 27.9 kg/m² (95% CI = 27.4–28.4) as compared to intermediate (mean = 25.5 kg/m²; 95% CI = 25.2–25.8) and low scorers (mean = 23.0 kg/m²; 95% CI = 22.7–23.3). In within‐pair analyses among 598 same‐sex twin pairs, the adjusted association between Restraint Scale scores and BMI persisted even when genetic and shared environmental factors were controlled for (adjusted β = 0.18; 95% CI = 0.12–0.24; P < 0.001), as did the association with weight gain (adjusted β = 0.37; 95% CI = 0.13–0.61; P = 0.003). In stratified analyses, dizygotic (DZ) twins differed more in BMI for a given difference in the Restraint Scale score than monozygotic (MZ) twins, for whom genetics are 100% controlled (adjusted β = 0.32; 95% CI = 0.20–0.44 vs. adjusted β = 0.10; 95% CI = 0.04–0.16; P = 0.001 for test of interaction). These data demonstrate that observed relationships between BMI, weight gain, and restrained eating, as assessed by the Restraint Scale, have a strong environmental influence and are not solely due to shared genetic factors.     

Sex difference in heritability of BMI in South Korean adolescent twins

Twin studies of BMI on the basis of Asian twins are extremely rare. Eight hundred eighty-eight pairs of twins [279 monozygotic (MZ) and 82 dizygotic (DZ) pairs of male twins, 319 MZ and 82 DZ pairs of female twins, and 126 opposite-sex pairs of DZ twins] completed items concerning height and weight through a mail and a telephone survey. A general sex-limitation model was applied to the data. Heritability estimate was greater among women than among men. However, there was little evidence of sex-specific genes. Under the best-fitting model, additive genetic variances were 82% [95% confidence interval (CI): 72% to 95%] for men and 87% (95% CI: 77% to 99%) for women; shared environmental variances were negligible in both men and women. These estimates of genetic and environmental factors in BMI found among South Korean adolescent twins were broadly in the range of those reported in previous studies of BMI based on Western twin samples.     

Genetic and Environmental Influences on Body‐Fat Measures among African‐American Twins

Objective: To investigate the genetic and environmental influences on body‐fat measures including waist circumference (WC), waist‐to‐hip ratio (WHR), and body mass index (BMI) among African‐American men and women. Research Methods and Procedures: Measurements were taken as part of the Carolina African American Twin Study of Aging. This sample currently comprises 146 same‐sex African‐American twins with an average age of 50 years (range, 22 to 88 years). This analysis included 26 monozygotic and 29 dizygotic men and 45 monozygotic and 46 dizygotic women. Maximum likelihood quantitative genetic analysis was used. Results: In men, additive genetic effects accounted for 77% of the variance in WC, 59% in WHR, and 89% in BMI. In women, additive genetic effects accounted for 76% of the variance in WC, 56% in WHR, and 73% in BMI. The remaining variance in both men and women was attributed to unique environmental effects (WC, 21%; WHR, 36%; BMI, 11% in men and WC, 22%; WHR, 38%; BMI, 27% in women) and age (WC, 2%; WHR, 5% in men and WC, 2%; WHR, 6% in women). When BMI was controlled in the analysis of WC and WHR, it accounted for a portion of the genetic and environmental variance in WHR and over one‐half of the genetic and environmental variance in WC. Discussion: There are both genetic and environmental influences on WC, WHR, and BMI, and independent of BMI, there are genetic and environmental effects on WC and WHR among both genders. The results from this African‐American twin sample are similar to findings among white twin samples.     

Familial Resemblance in Eating Behaviors in Men and Women from the Quebec Family Study

Objective: It is commonly recognized that genetic, environmental, behavioral, and social factors are involved in the development of obesity. The family environment may play a key role in shaping children's eating behaviors. The purpose of this study was to estimate the degree of familial resemblance in eating behavioral traits (cognitive dietary restraint, disinhibition, and susceptibility to hunger). Research Methods and Procedures: Eating behavioral traits were assessed with the Three‐Factor Eating Questionnaire in 282 men and 402 women (202 families) from the Quebec Family Study. Familial resemblance for each trait (adjusted for age, sex, and BMI) was investigated using a familial correlation model. Results: The pattern of familial correlation showed significant spouse correlation for the three eating behavior phenotypes, as well as significant parent‐offspring and sibling correlations for disinhibition and susceptibility to hunger. According to the most parsimonious model, generalized heritability estimates (including genetic and shared familial environmental effects) reached 6%, 18%, and 28% for cognitive dietary restraint, disinhibition, and susceptibility to hunger, respectively. Discussion: These results suggest that there is a significant familial component to eating behavioral traits but that the additive genetic component appears to be small, with generalized heritability estimates ranging from 6% to 28%. Thus, non‐familial environmental factors and gene‐gene and gene‐environmental interactions seem to be the major determinants of the eating/behavioral traits.     

Associations of Aging and Birth Cohort with Body Mass Index in a Biethnic Cohort

Objective: To examine associations of aging and birth cohort with body mass index (BMI) in a biethnic cohort. Research Methods and Procedures: This was a longitudinal closed cohort study of 14, 500 white and African‐American men and women, 45 to 64 years of age, followed for 9 years. Aging was defined as the length of the interval in years between baseline and following visits. Birth cohort was defined by the year in which participants were born. Mixed model analyses were used to examine associations of aging, birth cohort, and BMI in four ethnicity‐gender groups. Results: We found that aging was associated with an increase in BMI in white and African‐American men and women. The associations between aging and BMI were stronger in the younger birth cohorts. Except for white women, younger birth cohort was associated with a higher BMI. After adjusting for aging, birth cohort was associated with an increase in BMI of 0.1 kg/m² [95% confidence interval (95% CI): ?0.1, 0.3] among white women. The corresponding values for African‐American women, white men, and African‐American men are 0.5 kg/m² (95% CI: 0.1, 0.9), 0.6 kg/m² (95% CI: 0.4, 0.8), and 0.6 kg/m² (95% CI: 0.2, 1.0), respectively. Discussion: Our analyses show that, in all except white women, people in this age range who were born later have a higher BMI at the same attained age. In all groups, people who are born later gained more weight as they aged. In general, subjects ages 45 to 64 years gained weight as they aged 9 years.     

A prospective study of breakfast consumption and weight gain among U.S. men

Objective: The aim was to investigate the association between breakfast consumption and long‐term weight gain in an adult male population. Research Methods and Procedures: We evaluated prospective data on 20,064 U.S men, 46 to 81 years of age, who participated in the Health Professionals Follow‐up Study. Data on body weight, dietary factors, and lifestyle variables were obtained by validated questionnaires. We examined weight gain during 10 years of follow‐up. Results: Overall, 5857 men had a weight gain of 5 kg or greater during 10 years of follow‐up. Breakfast consumption was inversely associated with the risk of 5‐kg weight gain after adjustment for age [hazard ratio (HR) = 0.77 (95% confidence interval [CI], 0.72 to 0.82)], and this association was independent of lifestyle and BMI at baseline [HR = 0.87 (95% CI, 0.82 to 0.93)]. Fiber and nutrient intakes partially explained the association between breakfast consumption and weight gain. The inverse association between breakfast consumption and weight gain was more pronounced in men with a baseline BMI of 25 kg/m² or lower [multivariate HR = 0.78 (95% CI, 0.70 to 0.87)] than in men who were overweight at baseline [HR = 0.92 (95% CI, 0.85 to 1.00)]. Furthermore, we observed that an increasing number of eating occasions in addition to three standard meals was associated with a higher risk of 5‐kg weight gain [HR = 1.15 (95% CI, 1.06 to 1.25, for ≥2 vs. 0 additional eating occasions)]. Discussion: These findings suggest that the consumption of breakfast may modestly contribute to the prevention of weight gain as compared with skipping breakfast in middle‐aged and older men.     

Genetic influences on growth traits of BMI: a longitudinal study of adult twins

Objective: To investigate the interplay between genetic factors influencing baseline level and changes in BMI in adulthood. Methods and Procedures: A longitudinal twin study of the cohort of Finnish twins (N = 10,556 twin individuals) aged 20–46 years at baseline was conducted and followed up 15 years. Data on weight and height were obtained from mailed surveys in 1975, 1981, and 1990. Results: Latent growth models revealed a substantial genetic influence on BMI level at baseline in males and females (heritability (h²) 80% (95% confidence interval 0.79–0.80) for males and h² = 82% (0.81, 0.84) for females) and a moderate‐to‐high influence on rate of change in BMI (h² = 58% (0.50, 0.69) for males and h² = 64% (0.58, 0.69) for females). Only very weak evidence for genetic pleiotropy was observed; the genetic correlation between baseline and rate of change in BMI was very modest (−0.070 (–0.13, −0.068) for males and 0.04 (0.00, 0.08) for females. Discussion: Our population‐based results provide a basis for identifying genetic variants for change in BMI, in particular weight gain. Furthermore, they demonstrate for the first time that such genetic variants for change in BMI are likely to be different from those affecting level of BMI.     

Effect of Smoking on the Paradox of High Waist‐to‐Hip Ratio and Low Body Mass Index

Objective: Research on diabetes mellitus (DM) indicates that people with a low body mass index (BMI) but a high waist‐to‐hip ratio (WHR) are in a particularly high‐risk group. The purpose of this study was to investigate the prevalence of and the effect of smoking on this paradoxical relationship. Research Methods and Procedures: Our study sample consisted of 3450 men and 4250 women who had participated in the Korean Nationwide Health Examination Survey. We divided the study sample into tertiles (low, medium, and high), according to the level of WHR and of BMI, which yielded nine different combinations. Individuals exhibiting so‐called paradox A had the highest WHR and the lowest BMI. Results: The prevalence of paradox A was 4.7% for men and 3.8% for women. The overall agreement of WHR and BMI groups was poor [for men: κ = 0.31 and 95% confidence interval (CI) = 0.29 to 0.34; for women: κ = 0.39 and 95% CI = 0.37 to 0.42 for women]. The odds ratios for subjects having paradox A were estimated using a logistic regression model after adjusting for age, age², height, education, smoking, use of alcohol, and exercise. The risk for paradox A among current smokers was 2.1‐fold (95% CI, 1.5 to 3.0) higher for men and 2.5‐fold (95% CI, 1.6 to 3.9) higher for women than for nonsmokers, after adjusting for age and covariates. Discussion: Cigarette smoking may increase the risk of paradox A. The findings of this study should be crossvalidated to different populations.     

Psychiatric and Medical Symptoms in Binge Eating in the Absence of Compensatory Behaviors

Objective: To explore the extent to which binge eating in the absence of compensatory behaviors (BE) is associated with psychiatric and medical symptoms in men and women and to control for the independent effects of BMI. Research Methods and Procedures: A series of regression models was applied to questionnaire data on 8045 twins, 18 to 31 years old, from a population‐based Norwegian registry. Results: BE was significantly associated with elevated obesity, overweight, symptoms of eating disorders, symptoms of anxiety and depression, panic attacks, depressive episodes, and reduced life satisfaction in both men and women. In women, BE was independently associated with insomnia and early menarche. In men, BE was independently associated with specific phobia, daily smoking, alcohol use, use of pain medication, impairment due to mental health, neck‐shoulder, lower back, and chronic muscular pain, and impairment due to physical health. Both men and women with BE reported higher rates of psychiatric treatment. Discussion: Our results indicate that there is substantial comorbidity between BE and psychiatric symptoms independently of BMI for both men and women. Medical symptoms co‐occur less frequently than previously reported from treatment‐seeking populations in women. Across all domains, the array of symptoms exhibited by men with BE was broader than that observed in women with BE. This observation suggests the importance of considering gender differences in future studies of psychiatric and medical morbidity, binge eating, and obesity.     

Overweight,Obesity, and Binge Eating in a Non‐clinical Sample of Five Brazilian Cities

Objective: To investigate the relationship between obesity/overweight and binge eating episodes (BEEs) in a large nonclinical population. Research Methods and Procedures: Consumers at shopping centers in five Brazilian cities (N = 2858) who participated in an overweight prevention program were interviewed and had weight and height measured to calculate BMI. Results: Prevalence of overweight (BMI = 25 to 29.9 kg/m²) was 46.6% for men and 36.6% for women. Obesity (BMI ≥ 30 kg/m²) was about two‐thirds of the prevalence of overweight. BEEs (subjects who binged one or more times per week over the last 3 months) in normal‐weight individuals was 1.4% for men and 3.9% for women, whereas in overweight/obese, these prevalences were 6.5% and 5.5%, respectively (p < 0.01). After adjustment for age, socioeconomic variables, and childhood obesity, those who reported BEEs had an odds ratio of being overweight/obese of 3.31 (95% confidence interval: 1.11 to 9.85) for men and 1.73 (95% confidence interval: 1.05 to 2.84) for women. Discussion: These findings indicate a strong association between episodes of binge eating and overweight/obesity, mainly among men.     

Genetic liability to disability pension in women and men: a prospective population-based twin study

Background

Previous studies of risk factors for disability pension (DP) have mainly focused on psychosocial, or environmental, factors, while the relative importance of genetic effects has been less studied. Sex differences in biological mechanisms have not been investigated at all.

Methods

The study sample included 46,454 Swedish twins, consisting of 23,227 complete twin pairs, born 1928–1958, who were followed during 1993–2008. Data on DP, including diagnoses, were obtained from the National Social Insurance Agency. Within-pair similarity in liability to DP was assessed by calculating intraclass correlations. Genetic and environmental influences on liability to DP were estimated by applying discrete-time frailty modeling.

Results

During follow-up, 7,669 individuals were granted DP (18.8% women and 14.1% men). Intraclass correlations were generally higher in MZ pairs than DZ pairs, while DZ same-sexed pairs were more similar than opposite-sexed pairs. The best-fitting model indicated that genetic factors contributed 49% (95% CI: 39–59) to the variance in DP due to mental diagnoses, 35% (95% CI: 29–41) due to musculoskeletal diagnoses, and 27% (95% CI: 20–33) due to all other diagnoses. In both sexes, genetic effects common to all ages explained one-third, whereas age-specific factors almost two-thirds, of the total variance in liability to DP irrespective of diagnosis. Sex differences in liability to DP were indicated, in that partly different sets of genes were found to operate in women and men, even though the magnitude of genetic variance explained was equal for both sexes.

Conclusions

The findings of the study suggest that genetic effects are important for liability to DP due to different diagnoses. Moreover, genetic contributions to liability to DP tend to differ between women and men, even though the overall relative contribution of genetic influences does not differ by sex. Hence, the pathways leading to DP might differ between women and men.     

A twin-study of genetic contributions to morningness–eveningness and depression

Circadian rhythms are associated with the preference for sleep–wake timing, also known as morningness–eveningness (ME). Both circadian rhythms and ME are influenced by genetic factors. Studies show an association between eveningness and depression. This study investigates the heritability of ME and whether ME and depression share common genetic influences. Study participants (n?=?1237) were from the Vietnam Era Twin Study of Aging, a longitudinal study of aging with a baseline in midlife. Participants received the Morningness–Eveningness Questionnaire (MEQ) and the Center for Epidemiologic Studies Depression (CES-D) Scale as part of an extensive neurocognitive and psychosocial assessment. MEQ correlations between members of twin pairs were 0.41 (95% CI 0.31–0.49) for monozygotic (MZ) twins and 0.28 for dizygotic (DZ) twins (95% CI 0.19–0.41). CES-D correlations were 0.38 (95% CI 0.28–0.46) for MZ twins and 0.24 (95% CI 0.14–0.36) for DZ twins. Greater eveningness (i.e. lower MEQ scores) was significantly related to more depression symptoms (phenotypic correlation?=??0.15 (95% CI ?0.21 to ?0.09). In the best fitting model, the heritability estimates are 0.42 for the MEQ and 0.37 for the CES-D. A significant genetic correlation of ?0.21 indicated that ME and depression share a significant amount of their underlying genetic variance. The genetic covariance between ME and depression accounted for 59.1% of the phenotypic correlation. Of the CES-D sub-scales, Depressed Mood and Interpersonal Difficulties were significantly heritable, while only Well-Being had a significant genetic correlation with ME. ME and depression are both heritable (ME 0.42, depression 0.37) and share common genetic factors, suggesting an overlap in etiology and the relevance of circadian rhythms to depression. Further study of this relationship may help elucidate etiological factors in depression and targets for treatment.     

BMI modifies associations of IL-6 genotypes with insulin resistance: the Framingham Study

Objective: The ?174 interleukin (IL)‐6 gene polymorphism has been proposed as a risk factor for type 2 diabetes, but data are conflicting. Because white fat is a major source of IL‐6 in resting individuals, we tested the hypothesis that BMI modifies the association among the IL‐6 genotype, insulin resistance (IR) (measured using the homeostasis model), and risk of diabetes. Research Methods and Procedures: Outcomes were assessed in a community‐based cohort study of 1525 adults (mean age, 55.6 years; 753 men), who participated in the Framingham Offspring Study during the 1991 to 1995 examinations. Results: We found a significant interaction between IL‐6 genotype and BMI on levels of IR in men (p < 0.0001), with obese homozygotes for the minor C allele being most resistant. The IL‐6‐BMI interaction was not significant (p = 0.46) in women. Among men with the CC genotype, increasing BMI was associated with increased prevalence of diabetes [odds ratio (OR) per unit increase in BMI, 1.30; 95% confidence interval (CI), 1.11 to 1.50] but not among those with the GG (OR, 1.10; 95% CI, 0.98 to 1.22) or GC genotype (OR, 1.05; 95% CI, 0.97 to 1.14). Discussion: The ?174 IL‐6 promoter polymorphism modifies the association of obesity with IR and diabetes risk in men. Weight loss regimens targeted at reducing the risk of diabetes may be of particular benefit for men with a ?174 IL‐6 CC genotype.     

Aspects of eating behaviors "disinhibition" and "restraint" are related to weight gain and BMI in women

Objective: The causes of adult weight gain leading to obesity are uncertain. We examined the association of adult weight gain and obesity with subscales of eating behavior characteristics in older women. Methods and Procedures: Current height and weight, eating behavior subscales (disinhibition subscales—habitual, situational, and emotional; restraint subscales—flexible and rigid; hunger subscales—internal and external) as assessed using the Eating Inventory (EI), and self‐reported body weight at six prior age intervals were reported by 535 women aged 55–65 years. Multiple regression analysis was used to examine the relationships between EI subscale scores and weight change from the age interval of 30–39 to 55–60 years and current BMI. Results: The strongest correlate of weight gain over 20 years was susceptibility to overeating in response to everyday cues within the environment (habitual disinhibition; partial correlation coefficient (r) = 0.25, P < 0.001); susceptibility to overeating in response to emotional states such as depression (emotional disinhibition) was a quantitatively weaker but significant correlate (partial r = 0.17, P < 0.001), and susceptibility to overeating in response to specific situations such as social occasions (situational disinhibition) was not associated with weight gain. Flexible control of dietary restraint attenuated the influence of habitual disinhibition in particular on weight gain and BMI, and was less effective in attenuating associations of emotional or situational disinhibition. Discussion: Lifestyle modification programs for prevention and treatment of adult‐onset obesity currently focus on reducing situational and emotional overeating; the results of this study suggest that a stronger emphasis on strategies that target habitual overeating may be warranted.     

Major Increase in Prevalence of Overweight and Obesity between 1987 and 2001 among Danish Adults

Objective: The aim of the study was to examine the secular trends in the prevalence of obesity (BMI ≥ 30.0 kg/m²) and overweight (25.0 ≤ BMI < 30.0 kg/m²) in Danish adults between 1987 and 2001. Research Methods and Procedures: The study included self‐reported weight and height of 10, 094 men and 9897 women 16 to 98 years old, collected in a series of seven independent cross‐sectional surveys. Prevalence and changes in prevalence of obesity and overweight stratified by sex and age groups were determined Results: The prevalence of obesity more than doubled between 1987 and 2001, in men from 5.6% to 11.8% [odds ratio (OR) = 2.3, 95% confidence interval (CI) = 1.9 to 2.8, p < 0.0001] and in women from 5.4% to 12.5% (OR = 2.6, 95% CI = 2.1 to 3.2, p < 0.0001), with the largest increase among the 16‐ to 29‐year‐old subjects (men, from 0.8% to 7.5%, OR = 10.2, 95% CI = 4.1 to 25.3, p < 0.0001; women, from 1.4% to 9.0% OR = 7.0, 95% CI = 3.5 to 14.1, p < 0.0001). Between 1987 and 2001, the prevalence of overweight increased from 34% to 40% in men and from 17% to 27% in women. Discussion: The prevalence of overweight and obesity in Denmark has increased substantially between 1987 and 2001, particularly among young adults, a development that resembles that of other countries. There is clearly a need for early preventive efforts in childhood to limit the number of obesity‐related complications in young adults.     

Gender Differences in Shame in Patients with Binge‐Eating Disorder

Objective: To examine the relationship between shame and the behavioral and attitudinal features of eating disorders in men and women diagnosed with binge‐eating disorder (BED). Research Methods and Procedures: Participants were 188 consecutively evaluated adults (38 men and 150 women) who met Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for BED. Participants were interviewed and completed a battery of measures assessing shame, behavioral and attitudinal features of eating disorders, and general psychological functioning. Results: Shame did not differ significantly by gender and was not associated with BMI or binge‐eating frequency. Shame was significantly associated with the attitudinal features of eating disorders, even after controlling for levels of depression and self‐esteem. When considered separately by gender and controlling for depression and self‐esteem, shame was associated with body dissatisfaction in men and with weight concern in women. Discussion: Men and women with BED, who presented for treatment, reported similar levels of shame. Overall, while shame was related to attitudinal features, the specific associations differed by gender. For men, shame was related to how dissatisfied they felt with their bodies, whereas for women, shame was associated with concerns about weight. Interestingly, shame was not related to BMI or binge‐eating frequency in men or women. These results provide preliminary support for self‐conscious emotions playing different roles in men and women with BED.     

BMI vs. waist circumference for identifying vascular risk

Objective: Current guidelines recommend measurement of both BMI and waist circumference (WC) in individuals with BMI between 25.0 and 34.9 kg/m². We investigated the relative contributions of BMI and WC toward identifying risk of adverse vascular events in a community‐based sample. Methods and Procedures: We evaluated Framingham Study participants (n = 4,195 person‐examinations, 53% women) using pooled logistic regression to assess the incremental prognostic utility of WC in predicting risk of a first cardiovascular disease (CVD) event in the three BMI categories (normal, <25 kg/m²; overweight, 25 to <30 kg/m²; obese, ≥ 30 kg/m²) and to assess the incremental prognostic utility of BMI and WC separately for predicting risk of a first cardiovascular event. Results: On follow‐up (16 years), 430 participants (158 women) had experienced a first CVD event. In overweight women, but not in overweight men, larger WC was found to be an independent predictor of CVD incidence, longitudinally (in women, multivariable‐adjusted odds ratio (OR) per s.d. increment in WC 1.86, 95% confidence interval (CI) = 1.03–3.36, P = 0.04; in men adjusted OR per s.d. increment in WC 0.91, 95% CI 0.60–1.38, P = 0.66). In obese individuals and in those with normal BMI, WC was not associated independently with incident CVD. When BMI and WC were analyzed separately for predicting risk of a first cardiovascular event, the c statistics associated with the multivariable CVD models incorporating BMI vs. WC were nearly identical in men and women. Discussion: Knowledge of WC aids identification of vascular risk among overweight women. Among normal weight or obese women and men (regardless of BMI category) WC did not appear to substantially add to prediction of risk of vascular events.     

Heritability of Eating Behavior Assessed Using the DEBQ (Dutch Eating Behavior Questionnaire) and Weight‐related Traits: The Healthy Twin Study

The heritability of eating behavior and body weight–related traits in Asian populations has not been reported. The purpose of this study was to estimate the heritability of eating behavior and the body weight–related traits of current weight and self‐reported past weight among twins and their families. Study subjects were 2,144 Korean, adult, same‐sex twins and their families at the ages between 20 and 65 years (443 monozygotic (MZ) and 124 dizygotic (DZ) twin pairs, and 1,010 individuals of their family). The Dutch Eating Behavior Questionnaire (DEBQ) was used to assess three eating behavior subscales measuring restraint, emotional eating, and external eating. A variance component approach was used to estimate heritability. After consideration of shared environmental effects and adjustment for age and sex effects, the heritability estimates ± s.e. among twins and their family members were 0.31 ± 0.036 for restraint, 0.25 ± 0.098 for emotional eating, 0.25 ± 0.060 for external eating, 0.77 ± 0.032 for measured current body weight, and 0.70 ± 0.051 for self‐reported weight at 20 years old. The three DEBQ subscales were associated with all weight related traits after adjustment for age and sex. These results suggest eating behaviors and weight‐related traits have a genetic influence, and eating behaviors are associated with obesity indexes. Our findings from Korean twin family were similar to those reported in Western populations.     

Liver enzymes as a predictor for incident diabetes in a Japanese population: the Hisayama study

Objective: We studied the relationship between liver enzymes and the development of diabetes in a general Japanese population. Research Methods and Procedures: A total of 1804 non‐diabetic subjects 40 to 79 years of age were followed‐up prospectively for a mean of 9.0 years. Results: During the follow‐up, 135 subjects developed diabetes. In both sexes, the age‐adjusted cumulative incidence of diabetes increased significantly with elevating quartiles of serum γ‐glutamyltransferase (GGT) and alanine aminotransferase (ALT) levels. This pattern was also observed in aspartate aminotransferase (AST) quartiles for men but not for women. In multivariate analyses after adjusting for comprehensive risk factors and other liver enzymes, the risk of developing diabetes was significantly higher in the highest GGT quartile than in the lowest quartile [odds ratio (OR), 2.54; 95% confidence interval (CI), 1.03 to 6.26 for men; OR, 5.73; 95% CI, 1.62 to 20.19 for women]. Similar results were observed in ALT quartiles (OR, 2.32; 95% CI, 0.91 to 5.92 for men; OR, 4.40; 95% CI, 1.38 to 14.06 for women) but not in AST quartiles in either sex. Significant positive associations of GGT and ALT with diabetes were seen within each stratified category of risk factors, namely fasting insulin, BMI, waist‐to‐hip ratio, high‐sensitivity C‐reactive protein, and alcohol consumption. In receiver operating characteristic analyses, the areas under the receiver operating characteristic curve of GGT and ALT were significantly larger than that of AST, fasting insulin, waist‐to‐hip ratio, or C‐reactive protein. Discussion: Our findings suggest that serum GGT and ALT concentrations are strong predictors of diabetes in the general population, independent of known risk factors.     

Psychosocial Stress and 13‐year BMI Change Among Blacks: The Pitt County Study

Adverse psychosocial exposures may partially drive the high rates of obesity among blacks. The objective of this study was to prospectively examine the relationship between perceived psychosocial stress and percent change in BMI among adult black men and women. We used data from 756 women and 416 men who were participants in the Pitt County Study, a community‐based, prospective cohort study of blacks in eastern North Carolina. Participants were aged 25–50 years of age on entry into the study in 1988 and follow‐up was obtained in 2001. Using multivariable linear regression, we calculated the adjusted mean percentage change in BMI over the follow‐up period for each tertile of baseline measures of the Perceived Stress Scale (low, medium, and high), adjusted for potential confounders. For black women, higher levels of psychosocial stress at baseline predicted higher adjusted percentage increase in BMI over the 13‐year follow‐up: low stress 12.0% (95% CI 9.6–14.4), medium stress 16.3% (95% CI 13.7–18.9), and high stress 15.5% (95% CI 13.1–17.8). For black men, perceived stress was not associated with percent BMI change. These data suggest that interventions targeting obesity in black women should consider the potential impact of emotional stress on weight change.