Showing papers in "International Journal of Obesity in 2006"
TL;DR: To refine the diagnosis of childhood obesity by creating new sex-specific centile curves for body fat and to base these references on a simple and affordable method that could be widely adopted in clinical practice and surveys.
Abstract: Objective: To refine the diagnosis of childhood obesity by creating new sex-specific centile curves for body fat and to base these references on a simple and affordable method that could be widely adopted in clinical practice and surveys. Design: Body fat was measured by bio-impedance in 1985 Caucasian children aged 5-18 years from schools in Southern England. Smoothed centile charts were derived using the LMS method. Results: The new body fat curves reflect the known differences in the development of adiposity between boys and girls. The curves are similar by sex until puberty but then diverge markedly, with males proportionately decreasing body fat and females continuing to gain. These sex differences are not revealed by existing curves based on body mass index. We present charts in which cutoffs to define regions of 'underfat', 'normal', 'overfat' and 'obese' are set at the 2nd, 85th and 95th centiles. These have been designed to yield similar proportions of overweight/overfat and obese children to the IOTF body mass index cutoffs. Conclusions: Direct assessment of adiposity, the component of overweight that leads to pathology, represents a significant advance over body mass index. Our new charts will be published by the Child Growth Foundation for clinical monitoring of body fat, along with the software to convert individual measurements to Z-scores.
804 citations
TL;DR: Obesity is associated with oxidative stress and can be reduced with weight loss (regardless of exercise or surgery induced weight loss), caloric restriction or antioxidant rich diets, as well as with various lifestyle modifications and surgical interventions.
Abstract: Oxidative stress may be the unifying mechanism underlying the development of comorbidities in obesity. Evidence suggests that a clustering of sources of oxidative stress exists in obesity: hyperglycemia, hyperleptinemia, increased tissue lipid levels, inadequate antioxidant defenses, increased rates of free radical formation, enzymatic sources within the endothelium, and chronic inflammation. This review provides a summary of the available evidence on systemic oxidative stress in humans and specific metabolic pathways by which obesity may elevate systemic oxidant stress. The authors suggest possible methods of reducing oxidative stress such as antioxidant supplementation, caloric restriction and/or physical activity and surgical intervention to combat free radicals and reduce adipose tissue. Obesity is associated with oxidative stress and can be reduced with weight loss (regardless of exercise or surgery induced weight loss), caloric restriction or antioxidant rich diets. Oxidative stress levels are elevated in human obesity, and these levels are modifiable with various lifestyle modifications and surgical interventions.
689 citations
TL;DR: Investigation of plausible contributors to the obesity epidemic beyond the two most commonly suggested factors, reduced physical activity and food marketing practices found supportive evidence that in many cases is as compelling as the evidence for more commonly discussed putative explanations.
Abstract: Putative contributors to the secular increase in obesity: exploring the roads less traveled
628 citations
TL;DR: Values of WHTR during the past 10–20 years have increased greatly showing that central fatness in children has risen dramatically, and WHTR is more closely linked to childhood morbidity than body mass index (BMI).
Abstract: To examine the influence of age and gender on the waist:height ratio (WHTR) in children and to compare changes over time in WHTR, a measure of central fatness in British children. Representative cross-sectional surveys in 1977, 1987 and 1997. Great Britain and Northern Ireland. Survey 1: children aged 5–16 years measured in 1977 (boys) and 1987 (girls) (BSI, n=8135) and Survey 2: children aged 11–16 measured in 1997 (NDNS, n=773). From Survey 1, waist: height ratio related to age and sex and the proportion of children with a WHTR greater than 0.500 (a boundary value suggested for adults). From Survey 2, comparison of WHTR in children with that from Survey 1 and the actual proportion of children with a WHTR greater than 0.500 compared with the expected proportion using the survey 1 as reference. WHTR decreased with age (P<0.01 for trend), with the mean WHTR being significantly lower in girls (P<0.01). WHTR was significantly greater in children in Survey 2 compared with those measured 10 and 20 years earlier in Survey 1 (P<0.0001). The proportion of children where WHTR exceeded the 0.500 boundary value in Survey 2 was 17% of boys and 11.7% of girls (against 5.0 and 1.5%, respectively, in Survey 1, P<0.0001). The increase in WHTR in boys exceeded that in girls. Values of WHTR during the past 10–20 years have increased greatly showing that central fatness in children has risen dramatically. WHTR is more closely linked to childhood morbidity than body mass index (BMI) and we suggest it should be used as an additional or alternative measure to BMI in children as well as adults. A simple public health message that is the same for adults and children of both sexes and all ages could be stated as ‘keep your waist circumference to less than half your height’.
579 citations
TL;DR: This study shows the international consistency in perceptions of overweight in educated young men and women across diverse regions of the world, and confirms the patterning of women's overestimation of weight at lower BMI deciles and men's underestimation ofWeight at the higher deciles.
Abstract: Young women in the United States and Western Europe are notoriously concerned about weight but less is known about attitudes to weight in other regions of the world. This study explores the associations between body mass index (BMI), weight perceptions, and attempts to lose weight in male and female university students from 22 countries. Data were collected from 18 512 university students, using standardised methods, as part of the International Health Behaviour Survey. Measures included weight, height, perception of overweight, and weight loss status. BMI was calculated from weight and height, but was categorised into gender and country-standardised deciles rather than the conventional weight categories in response to the inaccuracy of self-reports. Perceived overweight and weight loss status were plotted against country-standardised BMI deciles. The 22 countries were grouped into five geopolitical/economic areas for regional analyses: North-Western Europe and the USA, Central and Eastern Europe, the Mediterranean, Pacific Asia, South America. Perceived overweight compared across the five regions. Perceived overweight increased systematically across BMI deciles in all countries. More women than men felt overweight at any decile. Women had low levels of perceived overweight in the lowest decile but rates rapidly increased to 50% by the 5th decile. Men, even in the highest deciles, were less aware that they are overweight and few of them were trying to lose weight. Women had a faster rise of weight loss attempts over the BMI deciles but nevertheless the proportion trying to lose in the highest decile did not exceed 75%. Perceived overweight profiles across BMI deciles were similar across all regions, suggesting that perceptions of overweight derive from local comparisons. The patterning for trying to lose weight was more diverse, with men and women from Asian countries showing higher levels of trying to lose weight at all deciles. This study shows the international consistency in perceptions of overweight in educated young men and women across diverse regions of the world. It confirms the patterning of women's overestimation of weight at lower BMI deciles and men's underestimation of weight at the higher deciles. Perceptions of overweight and attempts to lose weight were highest in the group of Asian countries where body weights are generally low, suggesting that local culture and norms could moderate attitudes to weight.
510 citations
TL;DR: The presence of an allosteric site on the CB1 receptor is discovered, one indication that CB1 and CB2 receptors can exist in a constitutively active state and it may also prove possible to enhance ‘autoprotective’ effects of released endocannabinoids with CB1 allosterIC enhancers or, indeed, to reduce proposed ‘autoimpairing” effects ofreleased endoc cannabinoidoids such as excessive food intake with CB 1 allosterics antagonists
Abstract: Mammalian tissues express at least two cannabinoid receptor types, CB1 and CB2, both G protein coupled. CB1 receptors are found predominantly at nerve terminals where they mediate inhibition of transmitter release. CB2 receptors occur mainly on immune cells, one of their roles being to modulate cytokine release. Endogenous agonists for cannabinoid receptors also exist, and are all eicosanoids. The first-discovered of these 'endocannabinoids' was arachidonoylethanolamide and there is convincing evidence that this ligand and some of its metabolites can activate vanilloid VRI (TRPV1) receptors. Certain cannabinoids also appear to have TRPV1-like and/or non-CB1, non-CB2, non-TRPV1 targets. Several CB1- and CB2-selective agonists and antagonists have been developed. Antagonists include the CB1-selective SR141716A, AM251, AM281 and LY320135, and the CB2-selective SR144528 and AM630. These all behave as inverse agonists, one indication that CB1 and CB2 receptors can exist in a constitutively active state. 'Neutral' cannabinoid receptor antagonists have also been developed. CB1 and/or CB2 receptor activation appears to ameliorate inflammatory and neuropathic pain and certain multiple sclerosis symptoms. This might be exploited clinically by using CB1, CB2 or CB1/CB2 agonists, or inhibitors of the membrane transport or catabolism of endocannabinoids that are released in increased amounts, at least in animal models of pain and multiple sclerosis. We have recently discovered the presence of an allosteric site on the CB1 receptor. Consequently, it may also prove possible to enhance 'autoprotective' effects of released endocannabinoids with CB1 allosteric enhancers or, indeed, to reduce proposed 'autoimpairing' effects of released endocannabinoids such as excessive food intake with CB1 allosteric antagonists.
493 citations
TL;DR: Imposing a speed that is just 10% higher than what overweight women would have self-selected led to a significant decline in reported pleasure, which could diminish the enjoyment of and intrinsic motivation for physical activity, reducing adherence.
Abstract: Objective: The lower rates of adherence to physical activity commonly found among overweight adults compared to their normal-weight counterparts might be due to the activity being experienced as more laborious and less pleasant, particularly when its intensity is prescribed (or imposed) rather than self-selected. Design: Within-subject design, with two 20-min sessions of treadmill exercise, one at self-selected speed and one at imposed speed, 10% higher than the self-selected. Subjects: A total of 16 overweight (BMI: 31 kg/m 2 ) and 9 normal-weight (BMI: 22 kg/m 2 ) previously sedentary but healthy women (age: 43 years). Measurements: Heart rate, oxygen uptake relative to body weight, and ratings of perceived exertion and pleasure–displeasure were assessed every 5 min. Results: The overweight women showed higher oxygen uptake and perceived exertion than the normal-weight women during both sessions. Although the two groups did not differ in ratings of pleasure–displeasure during the session at self-selected speed, only the overweight women showed a significant decline when the speed was imposed. Conclusions: Imposing a speed that is just 10% higher than what overweight women would have self-selected led to a significant decline in reported pleasure. Over time, this could diminish the enjoyment of and intrinsic motivation for physical activity, reducing adherence. International Journal of Obesity (2006) 30, 652–660. doi:10.1038/sj.ijo.0803052; published online 30 August 2005
470 citations
TL;DR: The findings suggest that the circulating MCP-1 and/or IL-8 may be a potential candidate linking obesity with obesity-related metabolic complications such as atherosclerosis and diabetes.
Abstract: Chemotactic cytokines, referred to as chemokines, play an important role in leukocyte trafficking. The circulating levels of chemokines have been shown to increase in inflammatory processes including obesity-related pathologies (e.g. atherosclerosis and diabetes). However, little is currently known about the relationship between chemokines and human obesity. In the present study, we investigated the circulating levels of selected chemokines (monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α), leukotactin-1, interleukin-8 (IL-8)) and the association between the chemokine levels and obesity-related parameters: body mass index (BMI), waist circumference, fasting glucose and insulin levels, lipids profile, and the level of C-reactive protein (CRP). A total of 100 subjects, 50 obese (BMI⩾25 kg/m2) and 50 who were not obese (BMI 30 kg/m2) compared with those of nonobese controls (BMI<25 kg/m2). The levels of CRP were positively correlated with BMI (P<0.001) or waist circumference (P<0.0001). The levels of MCP-1 and IL-8 were positively related to BMI (MCP-1, P<0.02; IL-8, P<0.01) and/or waist circumference (MCP-1, P<0.009; IL-8, P<0.03). The levels of MCP-1 were positively related to the levels of CRP (P<0.007) or interleukin-6 (IL-6) (P<0.0001), and negatively related to the levels of HDL-cholesterol (P<0.01). Homeostasis model assessment (HOMA) score was positively related to the levels of MCP-1 (P<0.02) or IL-8 (P<0.03) in obese subject. Our data demonstrated that the circulating levels of MCP-1 and IL-8 are related to obesity-related parameters such as BMI, waist circumference, CRP, IL-6, HOMA and HDL-cholesterol. These findings suggest that the circulating MCP-1 and/or IL-8 may be a potential candidate linking obesity with obesity-related metabolic complications such as atherosclerosis and diabetes.
468 citations
TL;DR: The body mass index in children and adolescents: considerations for population-based applications suggests that the index should be higher for girls and lower for boys.
Abstract: Body mass index in children and adolescents: considerations for population-based applications
462 citations
TL;DR: The adiposity rebound (AR) corresponds to the second rise in BMI curve that occurs between ages 5 and 7 years and is a useful tool for the paediatrician to monitor the child's adiposity development and for researchers to investigate the different developmental patterns leading to overweight.
Abstract: Childhood obesity is an important public health problem, with a rapidly increasing frequency worldwide. Identification of critical periods for the development of childhood and adolescent obesity could be very useful for targeting prevention measures. Weight status in early childhood is a poor predictor of adult adiposity status, and most obese adults were not obese as children. We first proposed to use the body mass index (BMI) charts to monitor individual BMI development. The adiposity rebound (AR) corresponds to the second rise in BMI curve that occurs between ages 5 and 7 years. It is not as direct a measure as BMI at any age, but because it involves the examination of several points during growth, and because it is identified at a time when adiposity level clearly change directions, this method provides information that can help us understand individual changes and the development of health risks. An early AR is associated with an increased risk of overweight. It is inversely associated with bone age, and reflects accelerated growth. The early AR recorded in most obese subjects and the striking difference in the mean age at AR between obese subjects (3 years) and non-obese subjects (6 years) suggest that factors have operated very early in life. The typical pattern associated with an early AR is a low BMI followed by increased BMI level after the rebound. This pattern is recorded in children of recent generations as compared to those of previous generations. This is owing to the trend of a steeper increase of height as compared to weight in the first years of life. This typical BMI pattern (low, followed by high body fatness level) is associated with metabolic diseases such as diabetes and coronary heart diseases. Low body fatness before the AR suggests that an energy deficit had occurred at an early stage of growth. It can be attributable to the high-protein, low-fat diet fed to infants at a time of high energy needs, the former triggering height velocity and the latter decreasing the energy density of the diet and then reducing energy intake. The high-fat, low-protein content of human milk may contribute to its beneficial effects on growth processes. Early (pre- and postnatal) life is a critical period during which environmental factors may programme adaptive mechanisms that will persist in adulthood. Under-nutrition in fetal life or during the first years after birth may programme a thrifty metabolism that will exert adverse effects later in life, especially if the growing child is exposed to overnutrition. These observations stress the importance of an adequate nutritional status in childhood and the necessity to provide nutritional intakes adapted to nutritional needs at various stages of growth. Because the AR reflects particular BMI patterns, it is a useful tool for the paediatrician to monitor the child's adiposity development and for researchers to investigate the different developmental patterns leading to overweight. It contributes to the understanding of chronic disease programming and suggests new approaches to obesity prevention.
442 citations
TL;DR: WC can be considered a good predictor of VAT as well as BMI of SAT, and the importance of ethnicity and gender on VAT estimation is not negligible.
Abstract: Background: The study of the relationship between anthropometry and visceral adipose tissue (VAT) is of great interest because VAT is associated with many risk factors for noncommunicable diseases and anthropometry is easy to perform in clinical practice. The studies hitherto available for children have, however, been performed on small sample sizes.
Design: Pooling of the data of studies published from 1992 to 2004 as indexed on Medline.
Aims: To assess the relationship between anthropometry and VAT and subcutaneous adipose tissue (SAT) as measured by magnetic resonance imaging (MRI) in children and to analyze the effect of age, gender, pubertal status and ethnicity.
Subjects and methods: Eligible subjects were 7–16 year-old, with availability of VAT and SAT, gender, ethnicity, body mass index (BMI) and waist circumference (WC). A total of 497 subjects were collected from seven different investigators and 407 of them (178 Caucasians and 229 Hispanics) were analyzed.
Results: Despite ethnic differences in MRI data, BMI, WC and age, no difference in VAT was found between Caucasians and Hispanics after correction for SAT and BMI. Univariate regression analysis identified WC as the best single predictor of VAT (64.8% of variance) and BMI of SAT (88.9% of variance). The contribution of ethnicity and gender to the unexplained variance of the VAT–WC relationship was low (3%) but significant (P0.002). The different laboratories explained a low (4.8%) but significant (P<0.0001) portion of the unexplained variance of the VAT–WC and SAT–BMI relationships. Prediction equations for VAT (VAT (cm2)=1.1 WC (cm)-52.9) and SAT (SAT (cm2)=23.2 BMI (kg/m2)-329) were developed on a randomly chosen half of the population and crossvalidated in the remaining half. The pure error of the estimate was 13 cm2 for VAT and 57 cm2 for SAT.
Conclusions: WC can be considered a good predictor of VAT as well as BMI of SAT. The importance of ethnicity and gender on VAT estimation is not negligible.
TL;DR: The authors recommend that long-term weight maintenance in adults be defined as a weight change of <3% of body weight.
Abstract: There is currently no consensus on the definition of weight maintenance in adults. Issues to consider in setting a standard definition include expert opinion, precedents set in previous studies, public health and clinical applications, comparability across body sizes, measurement error, normal weight fluctuations and biologic relevance. To be useful, this definition should indicate an amount of change less than is clinically relevant, but more than expected from measurement error or fluctuations in fluid balance under normal conditions. It is an advantage for the definition to be graded by body size and to be easily understood by the public as well as scientists. Taking all these factors into consideration, the authors recommend that long-term weight maintenance in adults be defined as a weight change of <3% of body weight.
TL;DR: This study indicates that behavioral and social factors exert critical influences on the onset of childhood overweight in preschool years, and interventions aimed at preventing childhood obesity would do well to target smoking pregnant women, as well as nonsmoking pregnant women at risk for giving birth to high-birth-weight children.
Abstract: The roots of the obesity epidemic need to be traced back as early in life as possible in order to develop effective means for preventing obesity and its health consequences in the future. The aim of this paper is to examine a broad range of factors that may simultaneously contribute to childhood overweight in a population-based cohort of children followed from birth to 4.5 years, to determine which factors exert the most influence in early life. The analyses were performed using data from the Quebec Longitudinal Study of Child Development 1998–2002 (QLSCD). The study follows a representative sample (n=2103) of children born in 1998 in the Canadian province of Quebec. Measured height and weight were available for 1550 children aged 4.5 years. At 4.5 years, BMI was analyzed using the US CDC sex- and age-specific growth charts. In order to study children at their highest weights at various ages, odds ratios were presented for high birth weight, weight-for-stature at or above the 95th percentile at 5 months, and BMI at or above the 95th percentile at 4.5 years. Monthly weight gain between birth and five months has been analyzed. Children were also evaluated by the Z-score obtained from the standardized weight divided by height. Factors potentially related to children's weight include sex, gestational age and birth rank, breastfeeding, mothers' smoking status during pregnancy, family type at child's birth, and family income before pregnancy and when the children were 5 months and 4.5 years old. Other parental factors such as height and overweight/obesity (based on BMI) and other maternal factors (age, education, immigrant status) were also part of the analysis. Being in the highest quintiles of weight gain between birth and 5 months, as well as maternal smoking during pregnancy, almost double the odds of being overweight at 4.5 years. Parental overweight or obesity also increased the odds of being overweight at this age, as well as being raised in middle-income or in poor families. A greater proportion of children born to nonsmoking mothers with higher weights (more than 4000 g) were overweight at 4.5 years, the percentage being greatest for those in the highest weight-gain categories from birth to 5 months. The pattern was different for children born to smoking mothers. The greatest proportion of 4.5-year-old overweight children was seen for children born in the normal weight-range category (3000–4000 g) who were in the highest quintiles of weight gain from birth to 5 months, and for children with high birth weights (more than 4000 g) who were in the lowest quintiles of birth-to-5-months weight gain. Children who were overweight at 4.5 years and who had been born to smoking mothers started life with a birth weight around that for the population means, but they gained more weight in the first 5 months of life than did the children of nonsmoking mothers. This study indicates that behavioral and social factors exert critical influences on the onset of childhood overweight in preschool years. From a population–health perspective, interventions aimed at preventing childhood obesity would do well to target smoking pregnant women, as well as nonsmoking pregnant women at risk for giving birth to high-birth-weight children, paying particular attention to rapid weight gain in the first months of life.
TL;DR: An inverse association was observed between sleep duration and the risk to develop childhood overweight/obesity, and Parental obesity, low parental educational level, low total family income, long hours of TV watching, playing videogames or computer utilization, absence of breastfeeding and physical inactivity were significantly associated with childhood obesity.
Abstract: To assess the relationship between short sleep duration and obesity-related variables in children involved in the ‘Quebec en Forme’ Project Cross-sectional study A total of 422 children (211 boys and 211 girls) aged between 5 and 10 years from primary schools in the City of Trois-Rivieres (Quebec) were selected to participate in this study Body weight, height and waist circumference were measured The children were classified as normal, underweight, overweight or obese, according to body mass index (BMI) per age An exhaustive questionnaire was administered by telephone to the parents of children The percentage of overweight/obesity was 200% in boys and 240% in girls When compared to children reporting 12–13 h of sleep per day, the adjusted odds ratio for childhood overweight/obesity was 142 (95% confidence interval 109–198) for those with 105–115 h of sleep and 345 (261–467) for those with 8–10 h of sleep after adjustment for age, sex, and other risk factors Parental obesity, low parental educational level, low total family income, long hours of TV watching, playing videogames or computer utilization, absence of breastfeeding and physical inactivity were also significantly associated with childhood overweight/obesity In addition, we observed a significant negative association adjusted for age between sleep duration and body weight (−033, P<001), BMI (−012, P<001) and waist circumference (−024, P<001) in boys An inverse association was observed between sleep duration and the risk to develop childhood overweight/obesity Longitudinal research will be required to confirm a potential link of causality between these variables
TL;DR: Investigation of the factors that contribute to lower rates of gynecological cancer screening as related to women's body size found strategies must be designed to reduce the weight barriers to these tests and improve the quality of the health care experience.
Abstract: Obese women are reported to be at higher risk from gynecological cancers than nonobese women, yet these women are less likely to get cancer-screening tests. The specific factors that contribute to obese women not obtaining timely cancer screening have not been identified. To investigate the factors that contribute to lower rates of gynecological cancer screening as related to women's body size. A purposeful sample of 498 White and African-American women with body mass index (BMI) from 25 to 122 kg/m2, including 60 women with BMI>55 kg/m2, was surveyed concerning access to gynecological cancer screening and potential barriers that could cause delay. Health care providers (N=129) were surveyed concerning their education, practices, and attitudes about providing care and gynecological cancer-screening tests for obese women. Obese women reported that they delay cancer-screening tests and perceive that their weight is a barrier to obtaining appropriate health care. The percent of women reporting these statements increased significantly as the women's BMI increased. Women with BMI>55 kg/m2 had a significantly lower rate (68%) of Papanicolaou (Pap) tests compared to others (86%). The lower screening rate was not a result of lack of available health care since more than 90% of the women had health insurance. Women report that barriers related to their weight contribute to delay of health care. These barriers include disrespectful treatment, embarrassment at being weighed, negative attitudes of providers, unsolicited advice to lose weight, and medical equipment that was too small to be functional. The percentage of women who reported these barriers increased as the women's BMI increased. Women who delay were significantly less likely to have timely pelvic examinations, Pap tests, and mammograms than the comparison group, even though they reported that they were ‘moderately’ or ‘very concerned’ about cancer symptoms. The women who delay care were also more likely to have been on weight-loss programs five or more times. Many health care providers reported that they had little specific education concerning care of obese women, found that examining and providing care for large patients was more difficult than for other patients, and were not satisfied with the resources and referrals available to provide care for them. Since the goal of preventive cancer screening is to improve health outcomes for all women and since obese women are at greater risk, strategies must be designed to reduce the weight barriers to these tests and improve the quality of the health care experience. Providers should receive specific training related to care of large women.
TL;DR: Several aspects of the FFE were associated with dietary outcomes likely to promote fatness in 5–6-year-old children, and parent's increased confidence in the adequacy of their child's diet was associated with increased consumption of sweet and savory snacks and decreased vegetable consumption.
Abstract: Background: The family food environment (FFE) is likely to exert important influences on young children's eating. Examination of multiple aspects of the FFE may provide useful insights regarding which of these might most effectively be targeted to prevent childhood obesity. Objective: To assess the associations between the FFE and a range of obesity-promoting dietary behaviors in 5-6-year-old children. Design: Cross-sectional study. Subjects: Five hundred and sixty families sampled from three socio-economically distinct areas. Measurements: Predictors included parental perceptions of their child's diet, food availability, child feeding practices, parental modeling of eating and food preparation and television (TV) exposure. Dietary outcomes included energy intake, vegetable, sweet snack, savory snack and high-energy (non-dairy) fluid consumption. Results: Multiple linear regression analyses, adjusted for all other predictor variables and maternal education, showed that several aspects of the FFE were associated with dietary outcomes likely to promote fatness in 5-6-year-old children. For example, increased TV viewing time was associated with increased index of energy intake, increased sweet snack and high-energy drink consumption, and deceased vegetable intake. In addition, parent's increased confidence in the adequacy of their child's diet was associated with increased consumption of sweet and savory snacks and decreased vegetable consumption. Conclusion: This study substantially extends previous research in the area, providing important insights with which to guide family-based obesity prevention strategies.
TL;DR: Data supports the role of oxyntomodulin as a potential anti-obesity therapy and increases energy expenditure while reducing energy intake resulting in negative energy balance.
Abstract: Oxyntomodulin increases energy expenditure in addition to decreasing energy intake in overweight and obese humans: a randomised controlled trial
TL;DR: Change in overweight status during the first 4 years in school is a significant risk factor for adverse school outcomes among girls but not boys and girls who become overweight during the early school years and those who start school being overweight and remain that way may need to be monitored carefully.
Abstract: To examine the link between childhood overweight status and elementary school outcomes. Prospective study design: multivariate regression models examining the association between changes in overweight status and school outcomes between kindergarten entry and end of third grade, after controlling for various child, family and school characteristics. Nationally representative sample of US children who entered kindergarten in 1998, with longitudinal data on body mass index (BMI) and school outcomes at kindergarten entry and end of third grade. Wide range of elementary school outcomes collected in each wave including academic achievement (math and reading standardized test scores); teacher reported internalizing and externalizing behavior problems (BP), social skills (self-control, interpersonal skills) and approaches to learning; school absences; and grade repetition. Measurements of height and weight in each wave were used to compute BMI and indicators of overweight status based on CDC growth charts. A rich set of control variables capturing child, family, and school characteristics. Moving from not-overweight to overweight between kindergarten entry and end of third grade was significantly associated (P<0.05) with reductions in test scores, and teacher ratings of social-behavioral outcomes and approaches to learning among girls. However, this link was mostly absent among boys, with two exceptions – boys who became overweight had significantly fewer externalizing BPs (P<0.05), but more absences from school compared to boys who remained normal weight. Being always-overweight was associated with more internalizing BP among girls but fewer externalizing BPs among boys. Change in overweight status during the first 4 years in school is a significant risk factor for adverse school outcomes among girls but not boys. Girls who become overweight during the early school years and those who start school being overweight and remain that way may need to be monitored carefully.
TL;DR: Obesity in adolescence may be associated with later depression in young adulthood, abdominal obesity among male subjects may be closely related to concomitant depression, and being overweight/obese both in adolescence and adulthood may be a risk for depression among female subjects.
Abstract: To examine the association between body size and depression in a longitudinal setting and to explore the connection between obesity and depression in young adults at the age of 31 years. This study forms part of the longitudinal Northern Finland 1966 Birth Cohort Study (N=12 058). The follow-up studies were performed at 14 and 31 years. Data were collected by postal inquiry at 14 years and by postal inquiry and clinical examination at 31 years. A total of 8451 subjects (4029 men and 4422 women) who gave a written informed consent and information on depression by three depression indicators at 31 years. Body size at 14 (body mass index (BMI) and 31 (BMI and waist-to-hip ratio (WHR)) years and depression at 31 years by three different ways: depressive symptoms by the HSCL-25-depression questionnaire (HSCL-25), the use of antidepressants and self-reported physician-diagnosed depression. Obesity at 14 years associated with depressive symptoms at 31 years; among male subjects using the cutoff point 2.01 in the HSCL-25 (adjusted odds ratio (OR) 1.97, 95% CI 1.06–3.68), among female subjects using the cutoff point 1.75 (adjusted OR 1.64, 95% CI 1.16–2.32). Female subjects who were obese both at baseline and follow-up had depressive symptoms relatively commonly (adjusted OR 1.40, 95% CI 1.06–1.85 at cutoff point 1.75); a similar association was not found among male subjects. The proportion of those who used antidepressants was 2.17-fold higher among female subjects who had gained weight compared to female subjects who had stayed normal-weighted (adjusted OR 2.17, 95% CI 1.28–3.68). In the cross-sectional analyses male subjects with abdominal obesity (WHR ⩾85th percentile) had a 1.76-fold risk of depressive symptoms using the cutoff 2.01 in the HSCL-25 (adjusted OR 1.76, 95% CI 1.08–2.88). Abdominally obese male subjects had a 2.07-fold risk for physician-diagnosed depression (adjusted OR 2.07, 95% CI 1.23–3.47) and the proportion of those who used antidepressants was 2.63-fold higher among obese male subjects than among male subjects without abdominal obesity (adjusted OR 2.63, 95% CI 1.33–5.21). Abdominal obesity did not associate with depression in female subjects. Obesity in adolescence may be associated with later depression in young adulthood, abdominal obesity among male subjects may be closely related to concomitant depression, and being overweight/obese both in adolescence and adulthood may be a risk for depression among female subjects.
TL;DR: In the leanest quintile at baseline, high job strain and low job control were associated with weight loss by follow-up, whereas among those in the highest BMI quintile, these stress indicators wereassociated with subsequent weight gain.
Abstract: Objective: Previous research has focused on overall associations between work stress and body mass index (BMI) ignoring the possibility that stress may cause some people to eat less and lose weight and others to eat more. Using longitudinal data, we studied whether work stress induced weight loss in lean individuals and weight gain in overweight individuals.
Design: Prospective cohort study.
Subjects: A total of 7965 British civil servants (5547 men and 2418 women) aged 35–55 at study entry (The Whitehall II study).
Measurements: Work stress, indicated by the job strain model and measured as job control, job demands and job strain, was assessed at baseline and BMI at baseline and at 5-year follow-up.
Results: In men, the effect of job strain on weight gain and weight loss was dependent on baseline BMI (Pless than or equal to0.03). In the leanest quintile (BMI 27 kg/m2), these stress indicators were associated with subsequent weight gain. No corresponding interaction was seen among women.
Conclusion: Inconsistent findings reported by previous studies of stress and BMI have generally been interpreted to indicate the absence of an association. In light of our results, the possibility of differential effects of work stress should also be taken into account.
TL;DR: Investigating whether the association between depressive mood and obesity differs as function of sex, age, and race in US adults after controlling for socio-economic variables found that young obese women, Hispanics in particular, are much more prone to depressive mood than nonobese women.
Abstract: Sustained depressive mood is a gateway symptom for a major depressive disorder. This paper investigated whether the association between depressive mood and obesity differs as function of sex, age, and race in US adults after controlling for socio-economic variables of martial status, employment status, income level and education level. A total of 44 800 nationally representative respondents from the 2001 Behavioral Risk Factor Surveillance Survey were studied. Respondents were classified as having experienced a depressive mood if they felt sad, blue, or depressed at least for 1 week in the previous month. The depressive mood was operationalized in terms of duration and sustenance, both defined based on number of days with depressive mood: 7+ and 14+ days. Age groups were classified as young (18–64 years) and old (65+ years). Obesity status was classified as: not overweight/obese (BMI<25); overweight (25⩽BMI<30); obese (BMI⩾30). Prevalence of prior-month depressive mood was 14.3 and 7.8% for 7+ and 14+ days, respectively. Controlling for race and socio-economic variables, both young overweight and obese women were significantly more likely to have experienced depressive mood than nonoverweight/nonobese women. Young overweight, but not obese, men were significantly more likely to have experienced depressive mood than nonoverweight/nonobese men. Young obese women were also significantly more likely to have a sustained depressive mood than nonoverweight/nonobese women. For old respondents, depressive mood and its sustenance were not associated with obesity in either sex. The relationship between the depressive mood and obesity is dependent upon gender, age, and race. Young obese women, Hispanics in particular, are much more prone to depressive mood than nonobese women. Future studies testing associations between depression and obesity should be sensitive to the influence of these demographic and socio-economic variables.
TL;DR: At the population level, measurement of body FM has no advantage over BMI and WC in the prediction of obesity-related metabolic risk, and measures of central adiposity (WC, WC/ht) tended to show closer associations with risk factors than measures of general adiposity, suggesting an equivalent value of methods.
Abstract: To compare the value of body fat mass (%FM) to indirect measures of general (body mass index (BMI)) and central adiposity (waist circumference (WC); waist-to-height ratio (WC/ht)) for the prediction of overweight- and obesity-related metabolic risk in a study population with a high prevalence of metabolic syndrome (MSX). BMI, WC, WC/ht, body composition (by air-displacement plethysmography) and metabolic risk factors: triglycerides, cholesterol, HDL-cholesterol (HDL-C), uric acid, systolic blood pressure (BPsys), insulin resistance by homeostasis model assessment (HOMA-IR) and C-reactive protein (CRP) were measured in 335 adults (191 women, 144 men; mean age 53 ±13.9 years, prevalence of MSX 30%). When compared with BMI and WC, %FM showed weaker associations with metabolic risk factors, except for CRP and BPsys in men. In women, HDL-C and HOMA-IR showed the closest correlations with BMI. For all other risk factors, WC or WC/ht were the best predictors in both sexes. Differences in the strength of correlations between an obesity index and different risk factors exceeded the differences observed between all obesity indices within one risk factor. In stepwise multiple regression analyses, WC/ht was the main predictor of metabolic risk in both sexes combined. However, analysis of the area under receiver operating characteristic curves for prediction of the prevalence of ⩾2 component traits of the MSX revealed a similar accuracy of all obesity indices. At the population level, measurement of body FM has no advantage over BMI and WC in the prediction of obesity-related metabolic risk. Although measures of central adiposity (WC, WC/ht) tended to show closer associations with risk factors than measures of general adiposity, the differences were small and depended on the type of risk factor and sex, suggesting an equivalent value of methods.
TL;DR: Evidence shows that it is possible to prevent obesity in children and adolescents through limited, school-based programs that combine the promotion of healthy dietary habits and physical activity.
Abstract: Preventive measures to contain the epidemic of obesity have become a major focus of attention. This report reviews the scientific evidence for medical interventions aimed at preventing obesity during childhood and adolescence. A systematic literature review involving selection of primary research and other systematic reviews. Articles published until 2004 were added to an earlier (2002) review by the Swedish Council on Technology Assessment in Health Care. Inclusion criteria required controlled studies with follow-up of at least 12 months and results measured as body mass index, skinfold thickness or the percentage of overweight/obesity. Children could be recruited from normal or high-risk populations. Combining the new data with the previous review resulted in an evaluation of 24 studies involving 25 896 children. Of these, eight reported that prevention had a statistically significant positive effect on obesity, 16 reported neutral results and none reported a negative result (sign test; P=0.0078). Adding the studies included in five other systematic reviews yielded, in total, 15 studies with positive, 24 with neutral and none with negative results. Thus, 41% of the studies, including 40% of the 33 852 children studied, showed a positive effect from prevention. These results are unlikely to be a random chance phenomenon (P=0.000061). Evidence shows that it is possible to prevent obesity in children and adolescents through limited, school-based programs that combine the promotion of healthy dietary habits and physical activity.
TL;DR: To test the validity of internationally accepted waist circumference action levels for adult Asian Indians, analysis of data from multisite cross-sectional epidemiological studies in north India identified high odds ratio for cardiovascular risk factor(s) and BMI level of ⩾25 kg/m2.
Abstract: To test the validity of internationally accepted waist circumference (WC) action levels for adult Asian Indians. Analysis of data from multisite cross-sectional epidemiological studies in north India. In all, 2050 adult subjects >18 years of age (883 male and 1167 female subjects). Body mass index (BMI), WC, waist-to-hip circumference ratio, blood pressure, and fasting samples for blood glucose, total cholesterol, serum triglycerides, and high-density lipoprotein cholesterol. In male subjects, a WC cutoff point of 78 cm (sensitivity 74.3%, specificity 68.0%), and in female subjects, a cutoff point of 72 cm (sensitivity 68.7%, specificity 71.8%) were appropriate in identifying those with at least one cardiovascular risk factor and for identifying those with a BMI >21 kg/m2. WC levels of ⩾90 and ⩾80 cm for men and women, respectively, identified high odds ratio for cardiovascular risk factor(s) and BMI level of ⩾25 kg/m2. The current internationally accepted WC cutoff points (102 cm in men and 88 cm in women) showed lower sensitivity and lower correct classification as compared to the WC cutoff points generated in the present study. We propose the following WC action levels for adult Asian Indians: action level 1: men, ⩾78 cm, women, ⩾72 cm; and action level 2: men, ⩾90 cm, women, ⩾80 cm.
TL;DR: Moderately obese children had similar emotional and school HRQOL scores as normal weight children, whereas in the physical domain, a significant difference was documented even in moderate obesity.
Abstract: To assess the impact of obesity on health-related quality of life (HRQOL) of children, and to compare HRQOL scores of obese children in a hospital versus community setting. A cross-sectional study in two clinical samples. A total of 182 children and adolescents recruited from the community pediatric clinics and a hospital-based obesity clinic. Obesity was defined as body mass index (BMI) >95th percentile for age and gender. Subjects were divided into quartiles of BMI Z-scores each containing 45 or 46 children. The first two quartiles correspond to normal BMI, 3rd and 4th quartiles represent moderate and severe obesity, respectively. HRQOL was assessed by the Pediatric Quality of Life Inventory™ (PedsQL™) questionnaire submitted by both children and their parents. Obese children reported significantly lower HRQOL in physical, social and school domains compared with normal weight children (P<0.01). Analyzing results of HRQOL by BMI quartiles showed that the emotional and school domains scores of the moderately obese children were similar to the normal BMI quartiles. Only in the 4th quartile, that of children with severe obesity, were scores significantly lower. In contrast, in both physical and social domains scores decreased progressively with increased BMI Z-scores. In the obese group, parents' scores were lower than the children's in all domains. HRQOL scores of obese children assessed in the hospital clinic were similar to that of obese children assessed in the community. Moderately obese children had similar emotional and school HRQOL scores as normal weight children, whereas in the physical domain, a significant difference was documented even in moderate obesity. Parents of obese children perceived their child's HRQOL lower than the children themselves. We believe that intervention programs aimed at improving HRQOL should be directed to both parents and children. Understanding the resilience of moderately obese children in school and emotional domains may assist us in the management of childhood obesity.
TL;DR: Based on the small number of short-term randomized trials currently available, an aerobic exercise prescription of 155–180 min/weeks at moderate-to-high intensity is effective for reducing body fat in overweight children/adolescents, but effects on body weight and central obesity are inconclusive.
Abstract: Efficacy of exercise for treating overweight in children and adolescents: a systematic review
TL;DR: Time spent watching television is a significant predictor of BMI and overweight in childhood, although the effect size appears small, it is larger than the effect sizes commonly reported for nutritional intake and physical activity.
Abstract: To assess the impact of television viewing during childhood and adolescence on body mass index (BMI) in children up to the age of 15 years. Unselected birth cohort, assessed at birth and every 2 years from age 3 to 15 years. In all, 1037 individuals were assessed at age 3 years. At age 15 years, 976 (95% of living cohort) continued to participate. Parental estimates of weekday television viewing between age 5 and 11 years. Self-reports of television viewing at age 13 and 15 years. Weight and height were measured at each age to calculate BMI. BMI and prevalence of overweight at all ages were significantly associated with mean hours of television viewing reported in the assessments up to that age. These associations were stronger in girls than boys. The associations remained significant after adjusting for parental body mass indices and socio-economic status. Time spent watching television is a significant predictor of BMI and overweight in childhood. Although the effect size appears small, it is larger than the effect sizes commonly reported for nutritional intake and physical activity. Television viewing should be regarded as an important contributing factor to childhood obesity.
TL;DR: In nonsmokers there is a positive association between serum TSH within the normal range and BMI, and in nonsmoker in the longitudinal study, there was a significant and positive association with BMI in those with serum T SH within thenormal range both in 1994 and 2001.
Abstract: To investigate whether there is an association between serum thyroid-stimulating hormone (TSH) within the normal range and body mass index (BMI). The study was performed in 6164 subjects (2813 males) who attended the fifth Tromso study in 2001, and in 1867 subjects (873 males) that attended both the fourth Tromso study in 1994/1995 as well as the fifth Tromso study. Height, weight, and serum TSH were measured in all subjects, and smoking status was recorded. Smokers and nonsmokers were analyzed separately. In the fifth Tromso study, serum TSH was positively and significantly associated with BMI in the nonsmokers. Within the normal TSH range (defined as the 2.5–97.5 percentile), nonsmoking males in the highest TSH quartile had a mean BMI 0.4 kg/m2 higher compared to those in the lower quartile, whereas the difference for nonsmoking women was 1.4 kg/m2. Similarly, in nonsmokers in the longitudinal study, there was a significant and positive association between delta serum TSH (serum TSH in 2001 minus serum TSH in 1994) and delta BMI in those with serum TSH within the normal range both in 1994 and 2001. In these subjects, the quartile with the highest delta serum TSH had a mean increase in BMI from 1994 to 2001 that was 0.3 kg/m2 higher compared to those in the quartile with the lowest delta serum TSH. For the smokers, relations between serum TSH and BMI were not statistically significant. In nonsmokers there is a positive association between serum TSH within the normal range and BMI.
TL;DR: This review introduces the principles of indirect (primarily open-circuit) calorimetry and explains some common misunderstandings.
Abstract: Indirect calorimetry is increasingly used to investigate why compounds or genetic manipulations affect body weight or composition in small animals. This review introduces the principles of indirect (primarily open-circuit) calorimetry and explains some common misunderstandings. It is not widely understood that in open-circuit systems in which carbon dioxide (CO2) is not removed from the air leaving the respiratory chamber, measurement of airflow out of the chamber and its oxygen (O2) content paradoxically allows a more reliable estimate of energy expenditure (EE) than of O2 consumption. If the CO2 content of the exiting air is also measured, both O2 consumption and CO2 production, and hence respiratory quotient (RQ), can be calculated. Respiratory quotient coupled with nitrogen excretion allows the calculation of the relative combustion of the macronutrients only if measurements are over a period where interconversions of macronutrients that alter their pool sizes can be ignored. Changes in rates of O2 consumption and CO2 production are not instantly reflected in changes in the concentrations of O2 and CO2 in the air leaving the respiratory chamber. Consequently, unless air-flow is high and chamber size is small, or rates of change of O2 and CO2 concentrations are included in the calculations, maxima and minima are underestimated and will appear later than their real times. It is widely appreciated that bigger animals with more body tissue will expend more energy than smaller animals. A major issue is how to compare animals correcting for such differences in body size. Comparison of the EE or O2 consumption per gram body weight of lean and obese animals is misleading because tissues vary in their energy requirements or in how they influence EE in other ways. Moreover, the contribution of fat to EE is lower than that of lean tissue. Use of metabolic mass for normalisation, based on interspecific scaling exponents (0.75 or 0.66), is similarly flawed. It is best to use analysis of covariance to determine the relationship of EE to body mass or fat-free mass within each group, and then test whether this relationship differs between groups.
TL;DR: Weight-loss improved risk factors associated with CVD, with some additional benefits of LC n-3 PUFA on triglycerides and adiponectin.
Abstract: Obesity, inflammation, insulin resistance and cardiovascular disease (CVD) risk are inter-related. Both weight-loss and long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) are independently known to reduce metabolic risk, but the combined effects are unclear. This study examines whether addition of LC n-3 PUFA to a low fat/high carbohydrate weight-loss programme results in greater improvements in inflammation, insulin sensitivity and CVD risk, than weight-loss alone. One hundred and sixteen overweight insulin-resistant women entered a 24-week randomised intervention study. Thirty-nine women were randomised to a weight-loss programme, with LC n-3 PUFA (WLFO), 38 to a weight-loss programme with placebo oil (WLPO), and 39 to receive placebo oil, with no weight-loss programme (control). Ninety-three women completed the study (35 WLFO, 32 WLPO and 26 control), with significant weight-loss in WLFO (10.8±1.0%) and WLPO (12.4±1.0%) compared to the control group (P<0.0001). The WLFO, but not WLPO or control group, showed significant increases in adipose tissue LC n-3 PUFA (0.34±0.20 vs 0.17±0.10 and 0.16±0.10 %DHA, P<0.0001). Weight-loss showed significant improvements in insulin sensitivity (P<0.001), lipid profile (triglycerides P<0.05) and inflammation (sialic acid P<0.05). Time*group effects showed significant decreases in triglycerides (P<0.05) and increases in adiponectin (P<0.01) with LC n-3 PUFA, in the WLFO vs WLPO groups. Weight-loss improved risk factors associated with CVD, with some additional benefits of LC n-3 PUFA on triglycerides and adiponectin. Given the current low dietary intake of LC n-3 PUFA, greater attention should be given to increase these fatty acids in the treatment of obesity.