Showing papers in "International Journal of Obesity in 2005"

Long-term weight loss after diet and exercise: a systematic review

Abstract: To assess the effectiveness of dietary interventions and exercise in long-term weight loss in overweight and obese people. A systematic review with meta-analysis. Overweight and obese adults—18 years old or older with body mass index (calculated as weight divided by the square of height in meters)>25. Medline, Cochrane Library and Lilacs databases up to March 2003. Also, published reviews and all relevant studies and their reference lists were reviewed in search for other pertinent publications. No language restrictions were imposed. Randomised clinical trials comparing diet and exercise interventions vs diet alone. All trials included a follow-up of 1 y after intervention. Two reviewers independently abstracted data and evaluated the studies’ quality with criteria adapted from the Jadad Scale and the Delphi list. The estimate of the intervention's effect size was based on the differences between the comparison groups, and then the overall effect was calculated. A chi-squared test was used to assess statistical heterogeneity. A total of 33 trials evaluating diet, exercise or diet and exercise were found. Only 6 studies directly comparing diet and exercise vs diet alone were included (3 additional studies reporting repeated observations were excluded). The active intervention period ranged between 10 and 52 weeks across studies. Diet associated with exercise produced a 20% greater initial weight loss. (13 kg vs 9.9 kg; z=1.86—p=0.063, 95%CI). The combined intervention also resulted in a 20% greater sustained weight loss after 1 y (6.7 kg vs 4.5 kg; z=1.89—p=0.058, 95%CI) than diet alone. In both groups, almost half of the initial weight loss was regained after 1 y. Diet associated with exercise results in significant and clinically meaningful initial weight loss. This is partially sustained after 1 y.

Physical activity and sedentary behavior: a review of longitudinal studies of weight and adiposity in youth.

Abstract: To review the published prospective observational studies of the relationship of physical activity and sedentary behavior with the development of overweight and adiposity, with an emphasis on methodologic issues. Sample size, population studied, length of follow-up, assessment of exposure (physical activity, inactivity, or sedentary behavior), assessment of outcome (relative weight, overweight, % body fatness, adiposity), statistical approach, and main findings were extracted, summarized, and key methodological issues highlighted. In total, 17 studies of physical activity and 15 studies of inactivity/sedentary behavior were identified; as these were not mutually exclusive, 20 unique studies were reviewed. Results were mixed, with most studies showing an inverse association of physical activity with weight or fatness outcomes and/or a direct association of inactivity/sedentary behavior with weight or fatness outcomes. The effects identified were generally of small magnitude. Imprecise measurement of activity exposures likely weakens the observed relationships. Most studies used a pre–post design and had limited duration of follow-up (≤2 y). Studies with longer and more frequent follow-up did not always use the most advantageous statistical approach. On balance, the available evidence from prospective observational studies suggests that increased physical activity and decreased sedentary behavior are protective against relative weight and fatness gains over childhood and adolescence. In addition to improved measurement methods, longer and more frequent follow-up as well as truly longitudinal analysis methods would help establish these important prevention and intervention targets, and identify subgroups or development periods where interventions would likely be effective.

Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice

Abstract: Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice

Health consequences of obesity in the elderly: a review of four unresolved questions

Abstract: Obesity prevalence is growing progressively even among older age groups. Controversy exists about the potential harms of obesity in the elderly. Debate persists about the relation between obesity in old age and total or disease-specific mortality, the definition of obesity in the elderly, its clinical relevance, and about the need for its treatment. Knowledge of age-related body composition and fat distribution changes will help us to better understand the relationships between obesity, morbidity and mortality in the elderly. Review of the literature supports that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages. Weight gain or fat redistribution in older age may still confer adverse health risks (for earlier mortality, comorbidities conferring independent adverse health risks, or for functional decline). Evaluation of comorbidity and weight history should be performed in the elderly in order to generate a comprehensive assessment of the potential adverse health effects of overweight or obesity. The risks of obesity in the elderly have been underestimated by a number of confounders such as survival effect, competing mortalities, relatively shortened life expectancy in older persons, smoking, weight change and unintentional weight loss. Identification of elderly subjects with sarcopenic obesity is probably clinically relevant, but the definition of sarcopenic obesity, the benefits of its clinical identification, as well as its relation to clinical consequences require further study. Studies on the effect of voluntary weight loss in the elderly are scarce, but they suggest that even small amounts of weight loss (between 5-10% of initial body weight) may be beneficial. In older as well as in younger adults, voluntary weight loss may help to prevent the adverse health consequences of obesity.

The dual burden household and the nutrition transition paradox

Abstract: OBJECTIVE: The purpose of this study is to document the prevalence of households with underweight and overweight persons (henceforth referred to as dual burden households) and their association with income and urban residence. The explorations by urban residence and income will test whether dual burden households differ from 'underweight only' and 'overweight only' households, respectively. These comparisons are relevant to differentiating or adapting nutrition-related interventions wherever obesity and undernutrition cluster at the household level. POPULATION: Data analysis is based on national surveys conducted in Brazil, China, Indonesia, the Kyrgyz Republic, Russia, Vietnam and the United States. METHODS: All persons were first classified into categories for underweight and overweight, using body mass index (BMI) cutoffs, and then all households were categorized into four types: dual burden, overweight, underweight and normal. Income and urban residence were explored as key risk factors for being a dual burden household, with the effects modeled separately for each country. Multiple logistic regression was used to explore income and urban risk factors, controlling for household size, region of residence and either urban residence or income, as appropriate. RESULTS: In six of the countries studied, 22-66% of households with an underweight person also had an overweight person. Countries with the highest prevalence of dual burden households were those in the middle range of gross national product (GNP). The dual burden household is easily distinguished from the 'underweight only' households in Brazil, China, Indonesia, the United States and Vietnam. In these five countries dual burden households were more likely to be urban and more likely to be among the highest income tertile. There were no significant differences between dual burden and 'underweight only' households in Russia and the Kyrgyz Republic. In contrast, dual burden households were not easily distinguished from the 'overweight only' households in China, Indonesia, the Kyrgyz Republic, the United States and Vietnam. In Brazil and Russia dual burden households were more likely to be lower income and urban than 'overweight only' households. CONCLUSION: The prevalence of dual burden households presents a significant public health concern, particularly for those countries in the middle range of GNP. In some countries (China, Indonesia, the Kyrgyz Republic, the United States and Vietnam), dual burden households share sociodemographic profiles with overweight households, raising concerns for underweight individuals who may inadvertently become the focus of obesity prevention initiatives. For this reason, obesity prevention efforts should focus on messages that are beneficial to the good health of all, such as increasing fruit and vegetable intake, improving overall diet quality and increasing physical activity.

Relation of BMI to fat and fat-free mass among children and adolescents

Abstract: Although the body mass index (BMI, kg/m2) is widely used as a surrogate measure of adiposity, it is a measure of excess weight, rather than excess body fat, relative to height. We examined the relation of BMI to levels of fat mass and fat-free mass among healthy 5- to 18-y-olds. Dual-energy X-ray absorptiometry was used to measure fat and fat-free mass among 1196 subjects. These measures were standardized for height by calculating the fat mass index (FMI, fat mass/ht2) and the fat-free mass index (FFMI, fat-free mass/ht2). The variability in FFMI was about 50% of that in FMI, and the accuracy of BMI as a measure of adiposity varied greatly according to the degree of fatness. Among children with a BMI-for-age ≥85th P, BMI levels were strongly associated with FMI (r=0.85–0.96 across sex–age categories). In contrast, among children with a BMI-for-age <50th P, levels of BMI were more strongly associated with FFMI (r=0.56–0.83) than with FMI (r=0.22–0.65). The relation of BMI to fat mass was markedly nonlinear, and substantial differences in fat mass were seen only at BMI levels ≥85th P. BMI levels among children should be interpreted with caution. Although a high BMI-for-age is a good indicator of excess fat mass, BMI differences among thinner children can be largely due to fat-free mass.

BMI from 3–6 y of age is predicted by TV viewing and physical activity, not diet

Abstract: To investigate whether, diet, physical activity, sedentary behavior or television (TV) viewing predicted body mass index (BMI) among 3–7-y-old children. A triethnic cohort of 3–4-y-old children was followed for 3 y from 1986 to 1989. BMI was assessed at the beginning and end of each measurement year. Heart rate monitoring and observation were used to assess physical activity. Diet (calories, % calories from fat and carbohydrate), sedentary behavior and TV viewing were assessed by direct observation in each year. A repeated measures regression analysis with year as a factor and BMI at the end of each year as dependent variables was run. Nonsignificant variables were removed in a stepwise backward deletion process and significant interactions graphed. The interactions between minutes of TV viewing per hour and study year and minutes of physical activity per hour and study year were significant (P<0.05). There were also significant main effects for TV viewing, physical activity and BMI from the beginning of the study. The model accounted for 65% of the variance in BMI across the three study years. Plotting the significant interactions demonstrated that physical activity was positively associated with BMI in year 1, and negatively associated in years 2 and 3 with a stronger negative relationship in year 3 than 2. TV viewing became positively associated with BMI during the third study year. Physical activity and TV viewing were the only significant predictors (other than baseline BMI) of BMI among a triethnic cohort of 3–4-y-old children followed for 3 y with both physical activity (negatively associated) and TV viewing (positively associated) becoming stronger predictors as the children aged. It appears that 6 or 7 y is a critical age when TV viewing and physical activity may affect BMI. Therefore, focusing on reducing time spent watching television and increasing time spent in physical activity may be successful means of preventing obesity among this age group.

Monocyte chemoattractant protein-1 is produced in isolated adipocytes, associated with adiposity and reduced after weight loss in morbid obese subjects.

Abstract: Obesity is associated with insulin resistance and premature atherosclerosis. The human adipose tissue produce several adipokines including monocyte chemoattractant protein (MCP)-1, associated with cardiovascular disease and found to be involved in the pathogenesis of atherosclerosis in vitro. (1) To compare mRNA levels of MCP-1, leptin and a macrophage-specific marker (CD68) in isolated adipocytes vs stromal–vascular (SV) cells, (2) to compare mRNA levels of MCP-1 in human adipose tissue to circulating MCP-1 and adiposity (eg BMI: kg/m2) and (3) investigate the effect of weight loss in obese subjects on circulating MCP-1 and leptin. (1) MCP-1 and CD68 mRNA levels in isolated adipocytes vs SV cells were 17% (P<0.01) and ∼2% (P<0.001), respectively. Leptin mRNA levels in SV cells were ∼1% of that in isolated adipocytes (P<0.01). (2) MCP-1 mRNA levels correlated with circulating MCP-1 (P<0.05) and BMI (P<0.05). (3) A 12% weight loss (P<0.001) was associated with a 25% decrease in insulin levels (P<0.01). Circulating MCP-1 and leptin decreased by 20% (P<0.001) and by 24% (P<0.001), respectively. The findings demonstrate that MCP-1 is produced in isolated human adipocytes. In addition, the findings suggest that MCP-1 may be involved in obesity-related health complications and support the hypothesis that weight loss is beneficial by improving the low-grade inflammation observed in obesity.

Epigallocatechin gallate attenuates diet-induced obesity in mice by decreasing energy absorption and increasing fat oxidation

Abstract: To examine the antiobesity effect of epigallocatechin gallate (EGCG), a green tea bioactive polyphenol in a mouse model of diet-induced obesity. Obesity was induced in male New Zealand black mice by feeding of a high-fat diet. EGCG purified from green tea (TEAVIGO™) was supplemented in the diet (0.5 and 1%). Body composition (quantitative magnetic resonance), food intake, and food digestibility were recorded over a 4-week period. Animals were killed and mRNA levels of uncoupling proteins (UCP1–3), leptin, malic enzyme (ME), stearoyl-CoA desaturase-1 (SCD1), glucokinase (GK), and pyruvate kinase (PK) were analysed in different tissues. Also investigated were acute effects of orally administered EGCG (500 mg/kg) on body temperature, activity (transponders), and energy expenditure (indirect calorimetry). Dietary supplementation of EGCG resulted in a dose-dependent attenuation of body fat accumulation. Food intake was not affected but faeces energy content was slightly increased by EGCG, indicating a reduced food digestibility and thus reduced long-term energy absorption. Leptin and SCD1 gene expression in white fat was reduced but SCD1 and UCP1 expression in brown fat was not changed. In liver, gene expression of SCD1, ME, and GK was reduced and that of UCP2 increased. Acute oral administration of EGCG over 3 days had no effect on body temperature, activity, and energy expenditure, whereas respiratory quotient during night (activity phase) was decreased, supportive of a decreased lipogenesis and increased fat oxidation. Dietary EGCG attenuated diet-induced body fat accretion in mice. EGCG apparently promoted fat oxidation, but its fat-reducing effect could be entirely explained by its effect in reducing diet digestibility.

Dairy augmentation of total and central fat loss in obese subjects.

Abstract: BACKGROUND AND OBJECTIVE: We have previously demonstrated an antiobesity effect of dietary Ca; this is largely mediated by Ca suppression of calcitriol levels, resulting in reduced adipocyte intracellular Ca2+ and, consequently, a coordinated increase in lipid utilization and decrease in lipogenesis. Notably, dairy Ca is markedly more effective than other Ca sources. DESIGN: Obese subjects were placed on balanced deficit (−500 kcal/day) diets and randomized to control (400–500 mg Ca/day; n=16) or yogurt (1100 mg Ca/day; n=18) treatments for 12 weeks. Dietary macronutrients and fiber were held constant at the US average. MEASUREMENTS: Body weight, body fat and fat distribution (by dual-energy X-ray absorptiometry), blood pressure and circulating lipids were measured at baseline and after 12 weeks of intervention. RESULTS: Fat loss was markedly increased on the yogurt diet (−4.43±0.47 vs −2.75±0.73 kg in yogurt and control groups; P<0.005) while lean tissue loss was reduced by 31% on the yogurt diet. Trunk fat loss was augmented by 81% on the yogurt vs control diet (P<0.001), and this was reflected in a markedly greater reduction in waist circumference (−3.99±0.48 vs −0.58±1.04 cm, P<0.001). Further, the fraction of fat lost from the trunk was higher on the yogurt diet vs control (P<0.005). CONCLUSION: Isocaloric substitution of yogurt for other foods significantly augments fat loss and reduces central adiposity during energy restriction.

Regulation of PPARγ activity during adipogenesis

Abstract: Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor regulating an array of diverse functions in a variety of cell types including regulation of genes associated with growth and differentiation Its most notable function is to regulate development of adipose tissue, which involves coordinating expression of many hundreds of genes responsible for establishment of the mature adipocyte phenotype Our recent studies have demonstrated a role for MEK/ERK signaling and CCAAT/enhancer binding proteins (C/EBP)β in regulating expression of PPARγ during adipogenesis Furthermore, we have shown that cAMP-dependent signaling along with C/EBPβ leads to the stimulation of PPARγ activity by mechanisms that probably involve production of PPARγ ligands Additionally, we have recently demonstrated that phosphorylation of C/EBPβ at a consensus ERK/GSK3 site is required for the PPARγ-associated expression of adiponectin during the terminal stages of adipogenesis GSK3β also influences PPARγ activity by regulating the turnover and subcellular localization of β-catenin, a potent transcriptional activator of Wnt signaling In fact, we have recently shown a crosstalk between PPARγ and β-catenin signaling Specifically, activation of PPARγ induces the degradation of β-catenin during preadipocyte differentiation by mechanisms that require GSK3β and the proteasome In contrast, expression of a GSK3β-phosphorylation-defective β-catenin renders β-catenin resistant to the degradatory action of PPARγ Interestingly, expression of the mutant β-catenin blocks expression of adiponectin and C/EBPα in response to the activation of PPARγ

Disc degeneration of the lumbar spine in relation to overweight.

Abstract: To study the association between overweight and lumbar disc degeneration. Population-based 4-y follow-up magnetic resonance imaging (MRI) study. The subjects were 129 working middle-aged men selected to the baseline magnetic resonance imaging (MRI) study from a cohort of 1832 men representing three occupations: machine drivers, construction carpenters, and office workers. The selection was based on the paticipants’age (40–45 y) and place of residence. MR images of the lumbar spines were obtained at baseline and at 4-y follow-up. Signal intensity of the nucleus pulposus of the discs L2/L3–L4/L5 was visually assessed by two readers using the adjacent cerebrospinal fluid as an intensity reference. The weight (at age 25 and 40–45 y) and height of the subjects, history of car driving, smoking, and back injuries were assessed by questionnaire. Multiple regression analyses allowing for occupation, history of car driving, smoking, and back injuries showed that persistent overweight (body mass index (BMI) ≥25 kg/m2 at both ages) associated strongly with an increased risk of the number of lumbar discs with decreased signal intensity of nucleus pulposus at follow-up, adjusted odds ratio (OR) being 4.3 (95% confidence intervals (95% CIs) 1.3–14.3). Overweight at young age (risk ratio (RR) 3.8; 95% CI 1.4–10.4) was a stronger predictor of an increase in the number of degenerated discs during follow-up than overweight in middle age (RR 1.3; 95% CI 0.7–2.7). The study provides evidence that the BMI above 25 kg/m2 increases the risk of lumbar disc degeneration. Overweight at young age seems to be particularly detrimental.

Snacking frequency in relation to energy intake and food choices in obese men and women compared to a reference population.

Abstract: To investigate snacking frequency in relation to energy intake and food choices, taking physical activity into account, in obese vs reference men and women. Cross-sectional, descriptive study. In total, 4259 obese, middle-aged subjects (1891 men and 2368 women) from the baseline examination of the XENDOS study and 1092 subjects (505 men and 587 women) from the SOS reference study were included. A meal pattern questionnaire describing habitual intake occasions (main meals, light meals/breakfast, snacks, drink-only), a dietary questionnaire describing habitual energy and macronutrient intake and a questionnaire assessing physical activity at work and during leisure time were used. The obese group consumed snacks more frequently compared to the reference group (P<0.001) and women more frequently than men (P<0.001). Energy intake increased with increasing snacking frequency, irrespective of physical activity. Statistically significant differences in trends were found for cakes/cookies, candies/chocolate and desserts for the relation between energy intake and snacking frequency, where energy intake increased more by snacking frequency in obese subjects than in reference subjects. Obese subjects were more frequent snackers than reference subjects and women were more frequent snackers than men. Snacks were positively related to energy intake, irrespective of physical activity. Sweet, fatty food groups were associated with snacking and contributed considerably to energy intake. Snacking needs to be considered in obesity treatment, prevention and general dietary recommendations.

Ghrelin increases food intake in obese as well as lean subjects

Abstract: To investigate whether effects on food intake are seen in obese subjects receiving exogenous administration of ghrelin. Randomised, double-blind, placebo-controlled study of intravenous ghrelin at doses 1 pmol/kg/min and 5 pmol/kg/min. In all, 12 healthy lean subjects (mean body mass index (BMI) 20.5±0.17 kg/m2) and 12 healthy overweight and obese subjects (mean BMI 31.9±1.02 kg/m2). Food intake, appetite and palatability of food, ghrelin and other obesity-related hormones, growth hormone. Low-dose infusion of ghrelin increased ad libitum energy intake at a buffet meal in the obese group only (mean increase 36.6±9.4%, P<0.01.) High-dose ghrelin infusion increased energy intake in both groups (mean increase 20.1±10.6% in the lean and 70.1±15.5% in the obese, P<0.01 in both cases.) Ghrelin infusion increased palatability of food in the obese group. Ghrelin increases food intake in obese as well as lean subjects. Obese people are sensitive to the appetite-stimulating effects of ghrelin and inhibition of circulating ghrelin may be a useful therapeutic target in the treatment of obesity.

Angiogenic factors are elevated in overweight and obese individuals.

Abstract: Adipose tissue produces both vascular growth factors and inhibitors. Since obesity is associated with expansion of the capillary bed in regional adipose depots the balance between these factors may favor angiogenesis. To investigate the relationship between body mass index and serum concentrations of vascular growth factors in human subjects. Vascular endothelial growth factor (VEGF), VEGF-C, VEGF-D, soluble VEGF receptor-2 (sVEGFr2), hepatocyte growth factor (HGF), angiopoietin-2, angiogenin and endostatin concentrations were measured in serum collected from 58 lean (24 males, 34 female, mean BMI, 22.2±0.3) and 42 overweight and obese (16 males and 26 females, mean BMI, 33.5±1.2) subjects after an overnight fast. Sexual dimorphism was apparent in the serum concentrations of VEGF-C, VEFG-D and angiopoietin-2 with significantly higher levels in female compared to male subject. VEGF, VEGF-C, VEGF-D, soluble VEGF receptor-2, angiopoietin-2, angiogenin and endostatin but not HGF were significantly elevated in overweight and obese subjects. Positive correlations between BMI and the serum concentrations of VEGF-C, VEGF-D, sVEGF-R2, angiopoietin-2, angiogenin and endostatin were observed even after adjustment for gender and age. Increased levels of vascular growth factors as well as the angiogenesis inhibitor endostatin are present in overweight and obese subjects and may contribute to previously documented increased risk of metastatic disease in obese subjects with cancer.

Effects of the cannabinoid CB1 receptor antagonist SR141716 on oxygen consumption and soleus muscle glucose uptake in Lep(ob)/Lep(ob) mice.

Abstract: To investigate the effect of SR141716, a selective CB1 receptor antagonist, on energy expenditure and on glucose uptake in isolated soleus muscle of Lepob/Lepob mice. Female Lepob/Lepob mice (8–10 weeks old) were treated with SR141716 (10 mg/kg, i.p. once daily) or vehicle for 7 days. Oxygen consumption, daily food and water intake, body weight and glucose uptake in isolated soleus muscle. SR141716 (10 mg/kg, i.p. once daily) resulted in a significant reduction of daily food intake (P<0.01) and body weight (P<0.05) 5 days after daily treatment. Body weight continued to be lower for the rest of the treatment period (P<0.05). There was no significant difference in body weight between the pair-fed and vehicle-treated animals. A 7-day treatment with SR141716 (10 mg/kg, i.p. once daily) caused 37% increase in basal oxygen consumption compared to that of vehicle-treated (90 min mean; P<0.01), and a significant 68% increase in glucose uptake in isolated soleus muscle preparations. It is concluded that SR141716 has a direct effect on energy expenditure suggesting that the antiobesity effect of SR141716 is due to activation of thermogenesis in addition to the initial hypophagia. The increase in soleus muscle glucose uptake with SR141716 treatment may contribute to the improved glycaemia seen in the previous studies.

The effects of physical activity and body mass index on cardiovascular, cancer and all-cause mortality among 47 212 middle-aged Finnish men and women

Abstract: To examine the association of physical activity and body mass index (BMI), and their combined effect, with the risk of total, cardiovascular disease (CVD) and cancer mortality. Prospective follow-up study. In all, 22 528 men and 24 684 women aged 25–64 y at baseline having 7394 deaths during a mean follow-up of 17.7 y. A self-administered questionnaire data on smoking, socioeconomic factors, physical activity and medical history, together with measured height, weight, blood pressure and serum cholesterol using standardized protocol. Physically active subjects had significantly lower age-adjusted mortality from cardiovascular, cancer and all causes compared with sedentary ones. Further adjustment for smoking, systolic blood pressure, cholesterol, BMI, diabetes and education affected the results only slightly. Obese subjects (BMI≥30 kg/m2) had significantly higher cardiovascular and total mortality than the normal weight (18.5≤BMI<25 kg/m2) subjects. Part of increased mortality among obese subjects was mediated through obesity-related cardiovascular risk factors. BMI had an inverse association with cancer mortality among men and almost significant direct association among women. Total mortality was also increased among the lean (BMI<18.5 kg/m2) subjects. However, less than 0.3% of deaths were attributed to low body weight, whereas in men 5.5% and in women 17.7% of deaths were attributed to obesity. Regular physical activity and normal weight are both important indicators for a decreased risk of mortality from all causes, CVD and cancer. Physical activity had a strong independent effect on mortality, whereas the effect of BMI was partly mediated through other obesity-related risk factors.

Social class, parental education, and obesity prevalence in a study of six-year-old children in Germany.

Abstract: To assess the association between socioeconomic status (SES) and childhood obesity, and which factor in particular stands out in relation to obesity. When 2020 children attended their obligatory health exam prior to school entry in the City of Aachen, Germany, 1979 parents (97.9%) filled out a questionnaire on their child's weight development and on indicators of their family's SES in a cross-sectional survey. In addition, standardized measures of weight and height were taken. More detailed information on several different SES variables, such as parental education, occupation, income, family constellation, single parenthood, and the location and size of the family residence was obtained by personal interviews in a subsample of all native German speaking children with a BMI≥85th percentile, defined as cases (n=146), and with a BMI between the 40th and 60th percentile, defined as controls (n=221). The indicators of parental education were most strongly associated with children's obesity. There was a strong dose–response relationship between a composed index of social class and obesity. Children of the lowest social status had a more than three-fold risk to be obese than children of the highest social status in the screening population (OR: 3.29, CI: 1.92–5.63). The findings established a strong relationship between parental years of education and childhood obesity. Prevention and treatment programs should endeavor to better target undereducated parents and their young children at high risk.

Parental perceptions of overweight in 3-5 y olds.

Abstract: To assess the accuracy of parents' perceptions of their 3 to 5 y old children's weight status in a large UK sample. Parental perception and concern about child weight, demographic variables, and children's height and weight were obtained for 564 parent–child dyads. Only 1.9% of parents of overweight children and 17.1% of parents of obese children described their child as overweight. The odds of parents perceiving the child as overweight were increased for overweight (2.7; 95% CI 0.4, 16.5) and obese (28.5; 7.1, 115.4) compared with normal weight children, but were not associated with parental weight or with any demographic factors. Although few parents perceived their overweight children as overweight, more (66.2%) expressed concern about their overweight child becoming overweight in the future. Odds of concern were progressively higher for overweight (2.5; 1.6, 3.9) and obese children (4.6; 2.2, 9.7), and were also higher for parents who were themselves overweight (1.9; 1.2, 2.9) or obese (2.5; 1.3, 4.8). These findings suggest that parents of 3–5 y olds show poor awareness of their child's current weight status. Reframing discussions in terms of preventing future overweight may be an effective way to engage parents.

Human adenovirus-36 is associated with increased body weight and paradoxical reduction of serum lipids.

Abstract: Human adenovirus-36 (Ad-36) increases adiposity and paradoxically lowers serum cholesterol and triglycerides in chickens, mice, and non-human primates. The role of Ad-36 in human obesity is unknown. To determine the prevalence of Ad-36 antibodies in obese and nonobese humans. To evaluate the association of Ad-36 antibodies with body mass index (BMI) and serum lipids. Cohort study. Volunteers from obesity treatment programs, communities, and a research study. Obese and nonobese volunteers at the University of Wisconsin, Madison, WI, and the Bowen Center, Naples, Florida. Obese and thin volunteer research subjects and 89 twin pairs at Columbia University, New York. Study 1: 502 subjects; serum neutralization assay for antibodies to Ad-2, Ad-31, Ad-36, and Ad-37; serum cholesterol and triglycerides assays. Study 2: BMI and %body fat in 28 twin pairs discordant for Ad-36 antibodies. Presence of antibodies to adenoviruses, BMI, serum cholesterol and triglycerides levels. Significant (P<0.001) association of obesity and positive Ad-36 antibody status, independent of age, sex, and collection site. Ad-36 antibodies in 30% of obese, 11% of nonobese. Lower serum cholesterol and triglycerides (P<0.003) in Ad-36 antibody-positive vs -negative subjects. Twin pairs: antibody-positive twins had higher BMIs (24.5±5.2 vs 23.1±4.5 kg/m2, P<0.03) and %body fat (29.6±9.5% vs 27.5±9.9%, P<0.04). No association of Ad-2, Ad-31, or Ad-37 antibodies with BMI or serum lipids. Ad-36 is associated with increased body weight and lower serum lipids in humans. Prospective studies are indicated to determine if Ad-36 plays a role in the etiology of human obesity.

Tissue-specific regulation of metabolic pathways through the transcriptional coactivator PGC1-alpha.

Abstract: Metabolic pathways are controlled at different levels in response to environmental or hormonal stimuli. This control is achieved, at least in part, at the transcriptional level of gene expression. The regulation of gene expression is executed by specific transcription factors, but there is another level of regulation by a set of proteins that modulate these factors called transcriptional coactivators. In mammals, one of the most characterized examples of regulation of metabolic pathways by transcriptional coactivators is peroxisome proliferator-activated receptors gamma (PPARgamma) coactivator-1 alpha (PGC-1alpha). PGC-1alpha is activated by signals that control energy and nutrient homeostasis. Notably, PGC-1alpha induces and coordinates gene expression that stimulates mitochondrial biogenesis and a thermogenic program in brown fat, fiber-type switching in skeletal muscle, and metabolic pathways linked to the fasted response in the liver. PGC-1alpha activates gene expression through specific interaction with transcription factors that bind to the promoters of metabolic genes. These transcription factors can be ubiquitous such as the nuclear respiratory factors or tissue-enriched factors such as PPARgamma (brown fat), hepatocyte nuclear factor (HNF4alpha) (liver and pancreas) and muscle enhancer factor (MEF2s). The fact that PGC-1alpha controls important metabolic pathways in several tissues suggests that it can be a therapeutic target for antiobesity or diabetes drugs.

Effect of short-term high dietary calcium intake on 24-h energy expenditure, fat oxidation, and fecal fat excretion

Abstract: Observational studies have shown an inverse association between dietary calcium intake and body weight, and a causal relation is likely. However, the underlying mechanisms are not understood. We examined whether high and low calcium intakes from mainly low-fat dairy products, in diets high or normal in protein content, have effects on 24-h energy expenditure (EE) and substrate oxidation, fecal energy and fat excretion, and concentrations of substrates and hormones involved in energy metabolism and appetite. In all, 10 subjects participated in a randomized crossover study of three isocaloric 1-week diets with: low calcium and normal protein (LC/NP: 500 mg calcium, 15% of energy (E%) from protein), high calcium and normal protein (HC/NP: 1800 mg calcium, 15E% protein), and high calcium and high protein (HC/HP: 1800 mg calcium, 23E% protein). The calcium intake had no effect on 24-h EE or fat oxidation, but fecal fat excretion increased ∼2.5-fold during the HC/NP diet compared with the LC/NP and the HC/HP diets (14.2 vs 6.0 and 5.9 g/day; P<0.05). The HC/NP diet also increased fecal energy excretion as compared with the LC/NP and the HC/HP diets (1045 vs 684 and 668 kJ/day; P<0.05). There were no effects on blood cholesterol, free fatty acids, triacylglycerol, insulin, leptin, or thyroid hormones. A short-term increase in dietary calcium intake, together with a normal protein intake, increased fecal fat and energy excretion by ∼350 kJ/day. This observation may contribute to explain why a high-calcium diet produces weight loss, and it suggests that an interaction with dietary protein level may be important.

Impact of morbid obesity on medical expenditures in adults

Abstract: Morbid obesity (body mass index (BMI) ≥40 kg/m2) is associated with substantially increased morbidity and mortality from chronic health conditions and with poorer health-related quality of life; however, less is known about the impact of morbid obesity on healthcare expenditures. To examine the impact of morbid obesity on healthcare expenditures using a nationally representative sample of US adults. We performed a cross-sectional analysis of 16 262 adults from the 2000 Medical Expenditure Panel Survey, a nationally representative survey of the noninstitutionalized civilian population of the United States. Per capita healthcare expenditures were calculated for National Institutes of Health BMI categories, based on self-reported height and weight, using a two-part, multivariable model adjusted for age, gender, race, income, education level, type of health insurance, marital status, and smoking status. Odds of incurring any healthcare expenditure and per capita healthcare expenditures associated with morbid obesity in 2000. When compared with normal-weight adults, the odds of incurring any healthcare expenditure in 2000 were two-fold greater among adults with morbid obesity. Per capita healthcare expenditures for morbidly obese adults were 81% (95% confidence interval (CI): 48–121%) greater than normal-weight adults, 65% (95% CI: 37–110%) greater than overweight adults, and 47% (95% CI: 11–96%) greater than adults with class I obesity. Excess costs among morbidly obese adults resulted from greater expenditures for office-based visits, outpatient hospital care, in-patient care, and prescription drugs. Aggregate US healthcare expenditures associated with excess body weight among morbidly obese US adults exceeded $11 billion in 2000. The economic burden of morbid obesity among US adults is substantial. Further research is needed to identify interventions to reduce the incidence and prevalence of morbid obesity and improve the health and economic outcomes of morbidly obese adults.

Developmental coordination disorder and overweight and obesity in children aged 9-14 y.

Abstract: Developmental coordination disorder (DCD) is a significant problem that affects between 5 and 9% of all children. Since children with DCD are less likely than their non-DCD peers to participate in physical activities, they may be at greater risk for overweight and obesity. In this report, we examine the relationship between DCD and overweight and obesity in a sample of 578 children aged 9-14 y. We also examine whether the relationship between DCD and overweight/obesity is the same for boys and girls, taking into account sex and age-appropriate differences in percentage body fat and body mass index (BMI) criteria. Our results show that for boys, DCD may be a risk factor for overweight/obesity in childhood and early adolescence. For girls, there is no difference in the prevalence of overweight/obesity between children with and without the disorder.

Overweight and obesity associated with a missense polymorphism in fatty acid amide hydrolase (FAAH)

Abstract: The brain endogenous cannabinoid system modulates reward and craving pathways and consequently may affect body weight. A naturally occurring missense polymorphism in the gene encoding fatty acid amide hydrolase (FAAH), the primary enzyme for inactivation of endocannabinoids, is associated with problem drug use. To investigate the relationship between the FAAH cDNA 385 A/A (P129T) polymorphism and overweight disorders in subjects of multiple ethnic backgrounds attending a medical screening clinic. A total of 2667 subjects of white, black and Asian ancestry were genotyped and stratified by a standardized clinic-based assessment of body mass index (BMI, weight in kilograms/(height in meters)2 or kg/m2). Subjects were genotyped for the FAAH cDNA 385 C → A polymorphism using allele-specific oligonucleotide hybridization methods by investigators blinded to all clinical information. BMI was calculated based on exact clinical measurements and World Health Organization ranges were used to stratify subjects. Statistical methods included the Fisher exact test, Mann–Whitney U-test and multivariable logistic regression analysis. The homozygous FAAH 385 A/A genotype was significantly associated with overweight and obesity in white subjects (P=0.005) and in black subjects (P=0.05) but not in a small group of Asians. The median BMI for all subjects was significantly greater in the FAAH 385 A/A genotype group compared to heterozygote and wild-type groups (P=0.0001). In white subjects, there was an increasing frequency of the FAAH 385 A/A genotype with increasing BMI categories of overweight (P=0.02) and obese (P=0.006) with the same trend in black subjects. These results suggest a role for the FAAH 385 A/A missense polymorphism as an endocannabinoid risk factor in overweight/obesity and may provide indirect evidence to support cannabinoid antagonist treatment strategies in overweight disorders.

Association between markers of the metabolic syndrome and lower urinary tract symptoms in the Third National Health and Nutrition Examination Survey (NHANES III)

Abstract: Association between markers of the metabolic syndrome and lower urinary tract symptoms in the Third National Health and Nutrition Examination Survey (NHANES III)

Use of information and communication technology and prevalence of overweight and obesity among adolescents.

Abstract: The prevalence of overweight and obesity has increased among children and adolescents, as well as among adults, and television viewing has been suggested as one cause. Playing digital games (video, computer and console games), or using computer may be other sedentary behaviors related to the development of overweight and obesity. To study the relationships of times spent on viewing television, playing digital games and using computer to overweight among Finnish adolescents. Mailed cross-sectional survey. Nationally representative samples of 14-, 16-, and 18-y-old (N=6515, response rate 70%) in 2001. Overweight and obesity were assessed by body mass index (BMI). The respondents reported times spent daily on viewing television, playing digital games (video, computer and console games) and using computer (for e-mail, writing and surfing). Data on timing of biological maturation, intensity of weekly physical activity and family's socio economic status were taken into account in the statistical analyses. Increased times spent on viewing television and using computer were associated with increased prevalence of overweight (obesity inclusive) among girls: compared to girls viewing television <1 h daily, the adjusted odds ratio (OR) for being overweight was 1.4 when spending 1–3 h, and 2.0 when spending ≥4 h daily on viewing television. In girls using computer ≥1 h daily, the OR for being overweight was 1.5 compared to girls using computer <1 h daily. The results were similar in boys, although not statistically significant. Time spent on playing digital games was not associated with overweight. Overweight was associated with using information and communication technology (ICT), but only with certain forms of ICT. Increased use of ICT may be one factor explaining the increased prevalence of overweight and obesity at the population level, at least in girls. Playing digital games was not related to overweight, perhaps by virtue of game playing being less sedentary or related to a different lifestyle than viewing television and using computer.

Percent body fat measured by BIA and DEXA in obese, African-American adolescent girls.

Abstract: To compare the estimation of body fat between bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DEXA) in overweight, African-American female adolescents. In total, 54 African-American adolescent female subjects were recruited for Study 1. Each adolescent's body mass index was greater than the 85th percentile and their average body fat was 45% according to DEXA. A total of 26 African-American adolescent female subjects were available for Study 2, and had an average body fat of 26% according to DEXA. Percent body fat was measured by DEXA and BIA. Seven different BIA equations were tested. Both sets of data were analyzed using Bland–Altman regression analyses, utilizing percent body fat measured by DEXA as the criterion. The Kushner equation provided estimates that were unaffected by body fat in both studies. Estimates were unbiased when applied to the exclusively overweight sample and biased when utilized with the separate sample of normal weight and obese girls. The remaining equations were biased, provided inconsistent estimates across body weight, or were biased and provided inconsistent estimates. Ethnicity-specific and ethnicity-combined equations performed similarly in the obese sample, but became more disparate when applied to a sample encompassing a wider body weight range. The limits of agreement between all BIA equations and the DEXA estimates ranged from 6 to 9%. The study suggests that the Kushner BIA equation is appropriate for use with African-American female adolescents across the weight spectrum, while the majority of BIA equations underestimated percent body fat as body fat increased.

Comparison of body fatness measurements by BMI and skinfolds vs dual energy X-ray absorptiometry and their relation to cardiovascular risk factors in adolescents

Abstract: To compare estimates of adiposity by dual emission X-ray absorptiometry (DXA), skinfolds and body mass index (BMI); and to evaluate the relation of these measures to cardiovascular risk in adolescents. In a cohort of adolescents participating in a longitudinal study of insulin resistance, Slaughter formulas were used to estimate adiposity from skinfolds and DXA was used to estimate adiposity as % body fat (%BF) and fat mass (FBM). BMI, blood pressure, lipids and insulin resistance were measured. Male and female, 11–17 y old (n=130). To compare DXA with two office-based methods of assessing fatness and cardiovascular risk. Slaughter estimates were highly correlated with DXA (%BF r=0.92, P=0.0001; FBM r=0.96, P=0.0001). Correlations were similar in heavy and thin children. BMI was also highly correlated with DXA (%BF r=0.85, P=0.0001; FBM r=0.95, P=0.0001), and these relations were stronger in heavy than thin children. BMI and the Slaughter formulas were similar to DXA in their relations to cardiovascular risk factors. Adiposity by BMI and Slaughter formulas are highly correlated with DXA and similarly related to cardiovascular risk factors. BMI is easy to obtain and is an acceptable method for initial office estimation of body fatness. BMI and skinfolds compare well with DXA in predicting adverse cardiovascular risk profile.

Change in body mass index and its impact on blood pressure: a prospective population study

Abstract: Overweight and obesity increase the risk of elevated blood pressure, but the knowledge of the effect of weight change on blood pressure is sparse. To investigate the association between change in body mass index (BMI) and change in diastolic blood pressure (DBP), systolic blood pressure (SBP), and hypertension status. Two population-based cross-sectional studies, one in 1984–86 and the other in 1995–97. The Nord-Trondelag Health Study (HUNT). We included 15 971 women and 13 846 men who were 20 y or older at the first survey, without blood pressure medication at both surveys and without diabetes, cardiovascular disease or dysfunction in daily life at baseline. Weight, height and blood pressure were measured standardised. Change in BMI was categorised as stable (initial BMI±0.1 kg/m2 each follow-up year), increased or decreased, and BMI was categorised by using World Health Organisation's categorisation (underweight BMI: <18.5 kg/m2, normal weight BMI: 18.5–24.9 kg/m2, overweight BMI: 25.0–29.9 kg/m2, obesity BMI≥30 kg/m2). An increase in BMI and a decrease in BMI were significantly associated with increased and decreased SBP and DBP, respectively, compared to a stable BMI in both genders and all age groups, although the strongest effect was found among those who were 50 y and older. The adjusted odds ratio for having hypertension at HUNT 2 was 1.8 (95% confidence interval (CI): 1.5, 2.2) among women and 1.6 (95% CI: 1.4,1.8) among men aged 20–49 y who increased their BMI compared to those who had stable BMI. A similar, but weaker association was found among women and men aged 50 y or more. The mean change in both SBP and DBP was higher for those who changed BMI category from first to the second survey than for those who were in the same BMI class at both surveys. Our result supports an independent effect of change in BMI on change in SBP and DBP in both women and men, and that people who increase their BMI are at increased risk for hypertension.