For better or worse: Relationship status and body mass index

Recent increases in the incidence of obesity and declines in marriage have prompted policymakers to implement policies to mitigate these trends. This paper examines the link between these two outcomes. There are four hypotheses (selection, protection, social obligation and marriage market) that might explain the relationship between marital status transitions and changes in Body Mass Index (BMI). The selection hypothesis suggests that those with a lower BMI are more likely to be selected into marriage. The protection hypothesis states that married adults will have better physical health as a result of the increased social support and reduced incidence of risky behavior among married individuals. The social obligation hypothesis states that those in relationships may eat more regular meals and/or richer and denser foods due to social obligations which may arise because of marriage. Finally, the marriage market hypothesis indicates that when adults are no longer in the marriage market they may not maintain a healthy BMI because doing so is costly and they are in a stable union—or on the other hand, adults may enhance their prospects in the marriage market by losing weight. Taking advantage of longitudinal data and complete marriage histories in the National Longitudinal Survey of Youth 1979, we estimate individual fixed effects models to examine associations between the change in log BMI and the incidence of overweight and obesity, and changes in relationship status controlling for the effects of aging and other respondent characteristics. We find no support for the marriage protection hypothesis. Rather we find evidence supporting the social obligation and marriage market hypotheses—BMI increases for both men and women during marriage and in the course of a cohabiting relationship. Separate analyses by race and ethnicity reveal substantial differences in the response of BMI to relationship status across these groups.     

25-Hydroxyvitamin D levels of children are inversely related to adiposity assessed by body mass index

Vitamin D deficiency is associated with wide range of pathologies. Some evidences have shown that low vitamin D circulating levels in children and adolescent are related to fat mass and obesity. The objectives of the present study were to characterize vitamin D status in children and adolescents and to determine if serum 25-hydroxyvitamin D (25(OH)D) concentration is related to adiposity assessed by body mass index (BMI). Serum 25(OH)D levels were measured by LIAISON method in 471 children and adolescents (2 to 18 years age) and analyzed according to gender, pubertal period, age, and BMI. An overall prevalence of 25(OH)D insufficiency and deficiency was present in the 67.1%. Lower 25(OH)D levels were found in females (25.56 ± 14.03 vs 29.71 ± 17.10 ng ml^?1; P = 0.004) and pubertal children (25.52 ± 13.97 vs 29.21 ± 16.83 ng ml^?1; P = 0.011). In addition, an inverse relation of BMI and age on 25(OH)D concentrations was observed in children. In conclusion, low vitamin D status was highly prevalent among children and adolescents. Of note, a non-lineal regression model showed that 39.6% of vitamin D levels variability was explained by BMI. These results indicate that adiposity assessed by BMI impacts vitamin D status.     

A new body shape index predicts mortality hazard independently of body mass index

Background

Obesity, typically quantified in terms of Body Mass Index (BMI) exceeding threshold values, is considered a leading cause of premature death worldwide. For given body size (BMI), it is recognized that risk is also affected by body shape, particularly as a marker of abdominal fat deposits. Waist circumference (WC) is used as a risk indicator supplementary to BMI, but the high correlation of WC with BMI makes it hard to isolate the added value of WC.

Methods and Findings

We considered a USA population sample of 14,105 non-pregnant adults () from the National Health and Nutrition Examination Survey (NHANES) 1999–2004 with follow-up for mortality averaging 5 yr (828 deaths). We developed A Body Shape Index (ABSI) based on WC adjusted for height and weight: ABSI had little correlation with height, weight, or BMI. Death rates increased approximately exponentially with above average baseline ABSI (overall regression coefficient of per standard deviation of ABSI [95% confidence interval: –]), whereas elevated death rates were found for both high and low values of BMI and WC. (–) of the population mortality hazard was attributable to high ABSI, compared to (–) for BMI and (–) for WC. The association of death rate with ABSI held even when adjusted for other known risk factors including smoking, diabetes, blood pressure, and serum cholesterol. ABSI correlation with mortality hazard held across the range of age, sex, and BMI, and for both white and black ethnicities (but not for Mexican ethnicity), and was not weakened by excluding deaths from the first 3 yr of follow-up.

Conclusions

Body shape, as measured by ABSI, appears to be a substantial risk factor for premature mortality in the general population derivable from basic clinical measurements. ABSI expresses the excess risk from high WC in a convenient form that is complementary to BMI and to other known risk factors.     

Body adiposity index and other indexes of body composition in the SAPHIR study: Association with cardiovascular risk factors

Objective:

The accuracy of anthropometric surrogate markers such as the body adiposity index (BAI) and other common indexes like the body mass index (BMI), waist‐to‐hip ratio (WHR) and waist‐to‐height ratio (WHtR) to predict metabolic sequelae is essential for its use in clinical practice.

Design and Methods:

Thus, we evaluated the strength of BAI and other indexes to relate with anthropometric parameters, adipocytokines, blood lipids, parameters of glucose‐homeostasis and blood pressure in 1,770 patients from the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR) study in a crosssectional design. Measurements were BAI, BMI, WHR, WHtR, abdominal subcutaneous and visceral adipose tissue (aSAT and VAT), total body adipose tissue mass, body weight, waist‐ and hip circumference (WC and HC), leptin, adiponectin, high‐density lipoprotein‐cholesterol (HDL‐C), low‐density lipoprotein‐cholesterol (LDL‐C), triglycerides (TG), fasting plasma glucose, fasting plasma insulin, the homeostasis model assessment of insulin resistance (HOMAIR), systolic and diastolic blood pressure.

Results and Conclusions:

BAI was significantly associated with leptin and HC. We conclude that BAI was the best calculator for leptin. BAI was inferior to BMI to predict anthropometric parameters other than HC, adiponectin, blood lipids, parameters of glucose homeostasis, and blood pressure in this cross‐sectional study.     

Physical exercise, body mass index, subcutaneous adiposity and body composition among Bengalee boys aged 10-17 years of Kolkata, India

A comparative study of 215 sedentary (no regular physical exercise undertaken) and 313 physically active (regular physical exercise undertaken) Bengalee boys aged 10-17 years was undertaken to investigate the differences in overall adiposity (body mass index), subcutaneous adiposity (skinfolds) and body composition (percent body fat, fat mass and fat mass index). Both groups had a similar age. The results revealed that boys who did not undertake regular physical exercise (NPE) had a significantly greater mean body mass index (BMI) compared with those who undertook regular physical exercise (PE); p < 0.001. The means for all the skinfolds as well as percent body fat (PBF), fat mass (FM) and fat mass index (FMI) were significantly higher among the NPE group. The percentile distributions of all these variables and indices were consistently higher among the NPE group. The results of ANOVA of physical exercise (PE = yes, NPE = no) and PBF, FM and FMI, with age as covariate, revealed that PE had a significant negative effect on all these measures of body composition even after controlling for the impact of age. The means in each case were greater among the NPE group. In conclusion, this study provided evidence that Bengalee boys, who undertook regular physical exercise, had significantly less adiposity compared with those who did not undertake regular physical exercise.     

Neuronal PTP1B regulates body weight, adiposity and leptin action

Obesity is a major health problem and a risk factor for type 2 diabetes. Leptin, an adipocyte-secreted hormone, acts on the hypothalamus to inhibit food intake and increase energy expenditure. Most obese individuals develop hyperleptinemia and leptin resistance, limiting the therapeutic efficacy of exogenously administered leptin. Mice lacking the tyrosine phosphatase PTP1B are protected from diet-induced obesity and are hypersensitive to leptin, but the site and mechanism for these effects remain controversial. We generated tissue-specific PTP1B knockout (Ptpn1(-/-)) mice. Neuronal Ptpn1(-/-) mice have reduced weight and adiposity, and increased activity and energy expenditure. In contrast, adipose PTP1B deficiency increases body weight, whereas PTP1B deletion in muscle or liver does not affect weight. Neuronal Ptpn1(-/-) mice are hypersensitive to leptin, despite paradoxically elevated leptin levels, and show improved glucose homeostasis. Thus, PTP1B regulates body mass and adiposity primarily through actions in the brain. Furthermore, neuronal PTP1B regulates adipocyte leptin production and probably is essential for the development of leptin resistance.     

Social defeat and footshock increase body mass and adiposity in male Syrian hamsters

Obesity is a world-wide epidemic, and many factors, including stress, have been linked to this growing trend. After social stress (i.e., defeat), subordinate laboratory rats and most laboratory mice become hypophagic and, subsequently, lose body mass; the opposite is true of subordinate Syrian hamsters. After social defeat, Syrian hamsters become hyperphagic and gain body mass compared with nonstressed controls. It is unknown whether this increase in body mass and food intake is limited to subordinate hamsters. In experiment 1, we asked, do dominant hamsters increase food intake, body mass, and adiposity after an agonistic encounter? Subordinate hamsters increased food intake and body mass compared with nonstressed controls. Although there was no difference in food intake or absolute body mass between dominant and nonstressed control animals, cumulative body mass gain was significantly higher in dominant than in nonstressed control animals. Total carcass lipid and white adipose tissue (WAT) (i.e., retroperitoneal and epididymal WAT) masses were significantly increased in subordinate, but not dominant, hamsters compared with nonstressed controls. In experiment 2, we asked, does footshock stress increase food intake, body mass, and adiposity. Hamsters exposed to defeat, but not footshock stress, increased food intake relative to nonstressed controls. In animals exposed to defeat or footshock stress, body mass, as well as mesenteric WAT mass, increased compared with nonstressed controls. Collectively, these data demonstrate that social and nonsocial stressors increase body and lipid mass in male hamsters, suggesting that this species may prove useful for studying the physiology of stress-induced obesity in some humans.     

Fenofibrate prevents and reduces body weight gain and adiposity in diet-induced obese rats

Fibrates are hypolipidemic drugs that activate the peroxisome proliferator-activated receptors. Since fibrates may also increase energy expenditure, we investigated whether fenofibrate (FF) had this effect in diet-induced obese rats. A 2-month administration of a high-fat palatable diet to adult rats increased body weight by 25% and white adipose mass by 163% compared with a standard diet. These effects were prevented by FF, both when administered for the 2 months of high-fat feeding and when given for only the second month. Consequently, FF-treated rats had a final body weight and white adipose tissue mass similar to untreated animals on the standard diet. FF also increased resting metabolic rate, hepatic peroxisomal and mitochondrial palmitoyl-dependent oxygen uptake and mRNA levels of acyl-CoA oxidase and lipoprotein lipase. Finally, FF lowered mRNA levels of uncoupling protein-2 and did not affect mitochondrial respiration in skeletal muscle. Therefore, FF seems to act as a weight-stabilizer mainly through its effect on liver metabolism.     

The estimation of body mass index and physical attractiveness is dependent on the observer's own body mass index

A disturbance in the evaluation of personal body mass and shape is a key feature of both anorexia and bulimia nervosa. However, it is uncertain whether overestimation is a causal factor in the development of these eating disorders or is merely a secondary effect of having a low body mass. Moreover, does this overestimation extend to the perception of other people''s bodies? Since body mass is an important factor in the perception of physical attractiveness, we wanted to determine whether this putative overestimation of self body mass extended to include the perceived attractiveness of others. We asked 204 female observers (31 anorexic, 30 bulimic and 143 control) to estimate the body mass and rate the attractiveness of a set of 25 photographic images showing people of varying body mass index (BMI). BMI is a measure of weight scaled for height (kg m(- 2)). The observers also estimated their own BMI. Anorexic and bulimic observers systematically overestimated the body mass of both their own and other people''s bodies, relative to controls, and they rated a significantly lower body mass to be optimally attractive. When the degree of overestimation is plotted against the BMI of the observer there is a strong correlation. Taken across all our observers, as the BMI of the observer declines, the overestimation of body mass increases. One possible explanation for this result is that the overestimation is a secondary effect caused by weight loss. Moreover, if the degree of body mass overestimation is taken into account, then there are no significant differences in the perceptions of attractiveness between anorexic and bulimic observers and control observers. Our results suggest a significant perceptual overestimation of BMI that is based on the observer''s own BMI and not correlated with cognitive factors, and suggests that this overestimation in eating-disordered patients must be addressed directly in treatment regimes.     

A resistin gene polymorphism is associated with body mass index in women

The potential association of resistin (RETN) gene variability with obesity-related phenotypes was investigated in 585 non-diabetic individuals of European descent. The polymorphism studied (–420 C>G) is located in the RETN gene 5-flanking region. A significant association between the polymorphism and body mass index and waist circumference was observed in the women subsample (n=356), where the G allele was somewhat less frequent in the overweight/obese group than in normal-weight individuals (0.25 vs. 0.32; p=0.040; OR=0.70 [0.50–0.98]). Female carriers of the G-allele presented a lower mean BMI than C/C homozygotes (25.5 vs. 26.8 kg/m²; p=0.010). Furthermore, when women were stratified by menopausal status, the association was restricted to premenopausal women (C/C homozygotes, mean BMI=26.3 kg/m²; G-carriers, 24.4 kg/m²; p=0.014). Our findings suggest that RETN gene variation has gender-specific effects on BMI and warrants further investigation of its implications for the development of obesity.     

Chronic exercise lowers the defended body weight gain and adiposity in diet-induced obese rats

The effects of running wheel exercise and caloric restriction on the regulation of body weight, adiposity, and hypothalamic neuropeptide expression were compared in diet-induced obese male rats over 6 wk. Compared with sedentary controls, exercising rats had reduced body weight gain (24%), visceral (4 fat pads; 36%) and carcass (leptin; 35%) adiposity but not insulin levels. Hypothalamic arcuate nucleus (ARC) proopiomelanocortin (POMC) mRNA expression was 25% lower, but ARC neuropeptide Y (NPY), agouti- related peptide, dorsomedial nucleus (DMN) NPY, and paraventricular nucleus (PVN) corticotropin- releasing hormone (CRH) expression was comparable to controls. Sedentary rats calorically restricted to 85% of control body weight reduced their visceral adiposity (24%), leptin (64%), and insulin (21%) levels. ARC NPY (23%) and DMN NPY (60%) were increased, while ARC POMC (40%) and PVN CRH (14%) were decreased. Calorically restricted exercising rats an half as much as ad libitum-fed exercising rats and had less visceral obesity than comparably restricted sedentary rats. When sedentary restricted rats were refed after 4 wk, they increased intake and regained the weight gain and adiposity of sedentary controls. While refed exercising rats and sedentary rats ate comparable amounts, refed exercising rats regained weight and adiposity only to the level of ad libitum-fed exercising rats. Thus exercise lowers the defended level of weight gain and adiposity without a compensatory increase in intake and with a very different profile of hypothalamic neuropeptide expression from calorically restricted rats. This may be due to exercise-related factors other than plasma insulin and leptin.     

Social defeat increases food intake, body mass, and adiposity in Syrian hamsters

Overeating and increases in body and fat mass are the most common responses to day-to-day stress in humans, whereas stressed laboratory rats and mice respond oppositely. Group housing of Syrian hamsters increases body mass, adiposity, and food intake, perhaps due to social confrontation-induced stress. In experiment 1 we asked, Does repeated social defeat increase food intake, body mass, and white adipose tissue (WAT) mass in Syrian hamsters? Male hamsters subjected to the resident-intruder social interaction model and defeated intermittently 15 times over 34 days for 7-min sessions significantly increased their food intake, body mass, and most WAT masses compared with nondefeated controls. Defeat significantly increased terminal adrenal norepinephrine, but not epinephrine, content. In experiment 2 we asked, Are 15 intermittent resident-intruder interactions necessary to increase body mass and food intake? Body mass and food intake of subordinate hamsters defeated only once were similar to those of nondefeated controls, but four or eight defeats similarly and significantly increased these responses. In experiment 3 we asked, Do intermittent defeats increase adiposity and food intake more than consecutive defeats? Four intermittent or consecutive defeats similarly and significantly increased food intake and body mass compared with nondefeated controls, but only intermittent defeats significantly increased all WAT masses. Consecutive defeats significantly increased mesenteric and inguinal WAT masses. Plasma leptin, but not insulin, concentrations were similarly and significantly increased compared with nondefeated controls. Collectively, social defeat, a natural stressor, significantly increased food intake, body mass, and adiposity in Syrian hamsters and may prove useful in determining mechanisms underlying human stress-induced obesity.     

Neuroretinal rim area and body mass index

Purpose

To examine associations between neuroretinal rim area, pressure related factors and anthropometric parameters in a population-based setting.

Methods

The population-based cross-sectional Beijing Eye Study 2006 included 3251 subjects with an age of 45+ years. The participants underwent a detailed ophthalmic examination. Exclusion criteria for our study were high myopia of more than -8 diopters and angle-closure glaucoma.

Results

The study included 2917 subjects with a mean age of 59.8±9.8 years (range: 45–89 years). Mean neuroretinal rim area was 1.97±0.38 mm², mean intraocular pressure 15.6±3.0 mmHg, mean diastolic blood pressure 79.0±5.9 mm Hg, mean systolic blood pressure 133.5±11.1 mmHg, and mean body mass index was 25.5±3.7. In univariate analysis, neuroretinal rim area was significantly associated with optic disc size, open-angle glaucoma, refractive error, age and gender. After adjustment for these parameters in a multivariate analysis, a larger neuroretinal rim area was significantly correlated with a higher body mass index (P<0.001), in addition to be associated with a lower intraocular pressure (P = 0.004), lower mean blood pressure (P = 0.02), and higher ocular perfusion pressure.

Conclusions

In a general population, neuroretinal rim as equivalent of the optic nerve fibers is related to a higher body mass index, after adjustment for disc area, refractive error, age, gender, open-angle glaucoma, intraocular pressure, blood pressure and ocular perfusion pressure. Since body mass index is associated with cerebrospinal fluid pressure, the latter may be associated with neuroretinal rim area. It may serve as an indirect hint for an association between cerebrospinal fluid pressure and glaucoma.     

Income and body mass index in Europe

The problem of obesity is alarming public health authorities around the world. Therefore, it is important to study its determinants. In this paper, we explore the empirical relationship between household income and body mass index (BMI) in nine European Union countries. Our findings suggest that, in general, the association is negative for women and nonexistent for men. Moreover, once we decompose household income into “own labor earnings” and “other household income”, we find that the different relationship for men and women appears to be driven by the negative relationship between BMI and “own labor earnings” for women.     

Changes of the body mass index during childhood

This article is devoted to the age changes of the Body Mass Index in Czech and Slovak children from 1.5 to 15 years of age. The anthropological survey was carried out in 1976-1978 in the whole region of the former Czechoslovakia. At the beginning of the research period children with normal weight predominate. After the seventh year of age there is a change and the BMI is increasing. As late as pre-puberty and puberty there is a change in a fractional part of the population, as children with overweight are increasing, more frequently in girls than in boys. However, its presence is not fundamentally increasing up to 15 years. The frequency differences in the different BMI categories between both sexes in the Czech and Slovak populations are only rarely statistically significant.