Prevalence of Overweight and Obesity and Weight Loss Practice among Beijing Adults, 2011

Objective

This study aims to determine the up-to-date prevalence of overweight and obesity, the distributions of body weight perception and weight loss practice in Beijing adults.

Methods

A cross-sectional study was conducted in 2011. A total of 2563 men and 4088 women aged 18–79 years from the general population were included. Data were obtained from questionnaire and physical examination.

Results

The prevalence of overweight (BMI 24–27.9 kg/m²) and obesity (BMI≥28 kg/m²) was 42.1% and 20.3% in men and 35.6% and 17.1% in women, respectively. Age was inversely associated with overweight in both sexes, and obesity in women. Education level was negatively associated with overweight and obesity in women but not in men. Only 49.1% men and 58.3% women had a correct perception of their body weight. Underestimation of body weight was more common than overestimation, especially in men, the older people, and those with low education level. The percentage of taking action to lose weight was inversely associated with men and old age, and positively associated with higher education level, higher BMI, and self-perception as “fat” (OR = 3.78 in men, OR = 2.91 in women). Only 26.1% of overweight/obese individuals took action to lose weight. The top two weight loss practices were to reduce the amount of food intake and exercise.

Conclusion

Overweight and obesity were highly prevalent with high incorrect body weight perceptions in the general adult population in Beijing. Weight loss practice was poor in overweight and obese individuals. Actions at multiple levels are needed to slow or control this overweight and obesity epidemic.     

Hormones and Obesity: Changes in Insulin and Growth Hormone Secretion Following Surgically Induced Weight Loss

Ten obese patients were subjected to insulin tolerance tests (0.2 unit per kg. regular insulin intravenously) and/or treadmill exercise tolerance testing (2.6 m.p.h. at 11° angulation) before and after surgically induced weight reduction. Immunoreactive growth hormone (IRGH) responses returned to normal with weight reduction in all but one—a grossly obese woman studied relatively early in the postoperative period when still far from the ideal body weight. Five of these patients and two additional subjects had intravenous glucose tolerance tests (0.5 g. per kg.) before and after weight reduction. In all, there was a significant diminution in immunoreactive insulin (IRI) values, accompained by little or no change in the glucose disappearance rate (K_G) and a significant improvement in insulin effectiveness as indicated by the calculated “insulinogenic index”. It was concluded that the abnormalities in IRGH and IRI secretion, as well as the insulin resistance in obesity, are probably secondary and not of primary importance in the etiology of this disorder.     

Overweight,Obesity and Weight Control

Evidence is cited showing that overweight is a health hazard, but that this is primarily true only when the excess weight is due to an excess accumulation of adipose tissue. Diagnosis of frank obesity should be established by a careful interpretation of height-weight tables and of all other pertinent data. Although many factors play an etiologic role, obesity can occur only when caloric intake exceeds caloric output, and can be obviated only when this imbalance is reversed. Therefore prevention of weight gain, which should receive increasing attention, and also satisfactory weight loss, both require that caloric output be increased through added physical activity and that caloric intake be decreased through diminished consumption. Success depends on recognizing the fallacy of all misleading misinformation, and on establishing permanent habits of regular exercise and of moderation in eating and drinking. Suggestions are made that can be effective guidelines to a commonsense program of weight control.     

Prevalence of Overweight and Obesity in Elderly People in Spain

Objective: To estimate the prevalence of obesity and overweight in the older adult population in Spain by sex, age, and educational level. Research Methods and Procedures: A cross‐sectional study was carried out in 2001 in a sample of 4009 persons representative of the noninstitutionalized population ≥60 years of age. Anthropometric measurements (BMI and waist circumference) were obtained using standardized techniques and equipment. Overweight was considered at a BMI of 25 to 29.9 kg/m² and obesity at a BMI of ≥30 kg/m². Central obesity was considered at a waist circumference of >102 cm in men and >88 cm in women. Results: The mean BMI was 28.2 kg/m² in men and 29.3 kg/m² in women. The prevalence of overweight and obesity in men was 49% and 31.5%, respectively. The corresponding percentages in women were 39.8% and 40.8%. The prevalence of obesity was higher in persons with no education than in those with third level education (i.e., university studies), especially among women (41.8% vs. 17.5%). The prevalence of central obesity was 48.4% in men and 78.4% in women. Differences by educational level were seen in only women, in whom the prevalence of central obesity was 80.9% in those with no education and 59% in those with third‐level education. Discussion: The prevalence of overweight and obesity in the Spanish adult elderly population is very high. Some other populations show similar prevalences, especially in Mediterranean countries. Socioeconomic conditions in Spain during the years these cohorts were born may partly explain the high‐frequency of obesity.     

The High Prevalence of Overweight and Obesity in Mexican Children

Objective: To establish the prevalence of overweight and obesity in Mexican children 10 to 17 years of age according to the percentiles from both the Centers of Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF). Research Methods and Procedures: Heights and weights were measured in children from nationally representative, randomly chosen households in the Mexican National Health Survey 2000. The study population consisted of 7862 boys and 8947 girls, 10 to 17 years of age. Measurements used were the percentage of children in the corresponding BMI categories for overweight and obesity specified by the CDC and the IOTF BMI percentiles. Results: The children were short, with mean Z scores for height by age varying from ? 0.62 ± 1.26 to ?1.12 ± 1.06 in boys and from ?0.45 ± 1.25 to ?1.19 ± 1.12 in girls. CDC‐based overweight prevalences varied by age from 10.8% to 16.1% in boys and 14.3% to 19.1% in girls, with obesity prevalences from 9.2% to 14.7% in boys and 6.8% to 10.6% in girls; these prevalences did not relate to stunting. IOTF‐based excess weight prevalences were similar, with higher overweight rates (boys, 15.4% to 18.8%; girls, 18.4% to 22.3%) but lower obesity rates (boys, 6.1% to 9%; girls, 5.9% to 8.2%). Discussion: Mexican children have one‐half the overweight/obesity prevalences of U.S. Mexican‐American children; however, there are higher rates in Northern Mexico, which is closer to the U.S. These escalating rates of excess weight demand new prevention, as well as management, policies.     

Pre-Pregnancy Body Mass Index in Relation to Infant Birth Weight and Offspring Overweight/Obesity: A Systematic Review and Meta-Analysis

Background

Overweight/obesity in women of childbearing age is a serious public-health problem. In China, the incidence of maternal overweight/obesity has been increasing. However, there is not a meta-analysis to determine if pre-pregnancy body mass index (BMI) is related to infant birth weight (BW) and offspring overweight/obesity.

Methods

Three electronic bibliographic databases (MEDLINE, EMBASE and CINAHL) were searched systematically from January 1970 to November 2012. The dichotomous data on pre-pregnancy overweight/obesity and BW or offspring overweight/obesity were extracted. Summary statistics (odds ratios, ORs) were used by Review Manager, version 5.1.7.

Results

After screening 665 citations from three electronic databases, we included 45 studies (most of high or medium quality). Compared with normal-weight mothers, pre-pregnancy underweight increased the risk of small for gestational age (SGA) (odds ratios [OR], 1.81; 95% confidence interval [CI], 1.76–1.87); low BW (OR, 1.47; 95% CI, 1.27–1.71). Pre-pregnancy overweight/obesity increased the risk of being large for gestational age (LGA) (OR, 1.53; 95% CI, 1.44–1.63; and OR, 2.08; 95% CI; 1.95–2.23), high BW (OR, 1.53; 95% CI, 1.44–1.63; and OR, 2.00; 95% CI; 1.84–2.18), macrosomia (OR, 1.67; 95% CI, 1.42–1.97; and OR, 3.23; 95% CI, 2.39–4.37), and subsequent offspring overweight/obesity (OR, 1.95; 95% CI, 1.77–2.13; and OR, 3.06; 95% CI, 2.68–3.49), respectively. Sensitivity analyses revealed that sample size, study method, quality grade of study, source of pre-pregnancy BMI or BW had a strong impact on the association between pre-pregnancy obesity and LGA. No significant evidence of publication bias was observed.

Conclusions

Pre-pregnancy underweight increases the risk of SGA and LBW; pre-pregnancy overweight/obesity increases the risk of LGA, HBW, macrosomia, and subsequent offspring overweight/obesity. A potential effect modification by maternal age, ethnicity, gestational weight gain, as well as the role of gestational diseases should be addressed in future studies.     

Leptin Levels Are Associated with Fat Oxidation and Dietary‐Induced Weight Loss in Obesity

Objective: To examine the relationship between fasting plasma leptin and 24‐hour energy expenditure (EE), substrate oxidation, and spontaneous physical activity (SPA) in obese subjects before and after a major weight reduction compared with normal weight controls. To test fasting plasma leptin, substrate oxidations, and SPA as predictive markers of success during a standardized weight loss intervention. Research Methods and Procedures: Twenty‐one nondiabetic obese (body mass index: 33.9 to 43.8 kg/m²) and 13 lean (body mass index: 20.4 to 24.7 kg/m²) men matched for age and height were included in the study. All obese subjects were reexamined after a mean weight loss of 19.2 kg (95% confidence interval: 15.1–23.4 kg) achieved by 16 weeks of dietary intervention followed by 8 weeks of weight stability. Twenty‐four‐hour EE and substrate oxidations were measured by whole‐body indirect calorimetry. SPA was assessed by microwave radar. Results: In lean subjects, leptin adjusted for fat mass (FM) was correlated to 24‐hour EE before (r = ?0.56, p < 0.05) but not after adjustment for fat free mass. In obese subjects, leptin correlated inversely with 24‐hour and resting nonprotein respiratory quotient (r = ?0.47, p < 0.05 and r = ?0.50, p < 0.05) both before and after adjustments for energy balance. Baseline plasma leptin concentration, adjusted for differences in FM, was inversely related to the size of weight loss after 8 weeks (r = ?0.41, p = 0.07), 16 weeks (r = ?0.51, p < 0.05), and 24 weeks (r = ?0.50, p < 0.05). Discussion: The present study suggests that leptin may have a stimulating effect on fat oxidation in obese subjects. A low leptin level for a given FM was associated with a greater weight loss, suggesting that obese subjects with greater leptin sensitivities are more successful in reducing weight.     

Interplay Between Weight Loss and Gut Microbiota Composition in Overweight Adolescents

The aim of this study was to determine the influence of an obesity treatment program on the gut microbiota and body weight of overweight adolescents. Thirty‐six adolescents (13–15 years), classified as overweight according to the International Obesity Task Force BMI criteria, were submitted to a calorie‐restricted diet (10–40%) and increased physical activity (15–23 kcal/kg body weight/week) program over 10 weeks. Gut bacterial groups were analyzed by quantitative real‐time PCR before and after the intervention. A group of subjects (n = 23) experienced >4.0 kg weight loss and showed significant BMI (P = 0.030) and BMI z‐score (P = 0.035) reductions after the intervention, while the other group (n = 13) showed <2.0 kg weight loss. No significant differences in dietary intake were found between both groups. In the whole adolescent population, the intervention led to increased Bacteroides fragilis group (P = 0.001) and Lactobacillus group (P = 0.030) counts, and to decreased Clostridium coccoides group (P = 0.028), Bifidobacterium longum (P = 0.031), and Bifidobacterium adolescentis (P = 0.044) counts. In the high weight–loss group, B. fragilis group and Lactobacillus group counts also increased (P = 0.001 and P = 0.007, respectively), whereas C. coccoides group and B. longum counts decreased (P = 0.001 and P = 0.044, respectively) after the intervention. Total bacteria, B. fragilis group and Clostridium leptum group, and Bifidobacterium catenulatum group counts were significantly higher (P < 0.001–0.036) while levels of C. coccoides group, Lactobacillus group, Bifidobacterium, Bifidobacterium breve, and Bifidobacterium bifidum were significantly lower (P < 0.001–0.008) in the high weight–loss group than in the low weight–loss group before and after the intervention. These findings indicate that calorie restriction and physical activity have an impact on gut microbiota composition related to body weight loss, which also seem to be influenced by the individual's microbiota.     

Prevalence of Overweight,Obesity, and Abdominal Obesity in a Representative Sample of Portuguese Adults

This study determined the prevalence of overweight, obesity, and abdominal obesity in the Portuguese adults and examined the relationship between above mentioned prevalences and educational level. Body mass, stature, and waist circumference were measured in a representative sample of the Portuguese population aged 18–103 years (n = 9,447; 18–64 years: n = 6,908; ≥65 years: n = 2,539). Overweight and obesity corresponded to a body mass index ranging between 25–29.9 kg/m² and ≥30 kg/m², respectively. Abdominal obesity was assessed as >102 cm for males and >88 cm for females. After adjusting for educational level, the combined prevalences of overweight and obesity were 66.6% in males and 57.9% in females (18–64 years). Respective values in older adults (≥65 years) were 70.4% for males and 74.7% for females. About 19.3% of adult males and 37.9% of adult females presented abdominal obesity. Correspondent values in older adults were 32.1%, for males, and 69.7%, for females. In adults, low educational level was related to an increased risk for overweight (OR = 2.54; 95% CI: 2.08–3.09), obesity (OR = 2.76; 95% CI: 2.20–3.45), and abdominal obesity (OR = 5.48; 95% CI: 4.60–6.52). This reinforces the importance of adjusting public health strategies for educational level.     

Alterations of Plasma Lysophosphatidylcholine Species in Obesity and Weight Loss

Background

Obesity and related diseases of the metabolic syndrome contribute to the major health problems in industrialized countries. Alterations in the metabolism of lipid classes and lipid species may significantly be involved in these metabolic overload diseases. However, little is known about specific lipid species in this syndrome and existing data are contradictive.

Methods

In this study, we quantified plasma lipid species by electrospray ionization tandem mass spectrometry (ESI-MS/MS) in obese subjects before and after 3 month weight loss as well as in a control group.

Results

The comparison of obese subjects with control subjects before weight loss revealed significantly lower lysophosphatidylcholine (LPC) concentrations in obesity. LPC concentrations did not significantly increase during the observed period in the weight loss group. Analysis of LPC species revealed a decrease of most species in obesity and negative correlations with C-reactive protein (CRP) and body mass index (BMI). Correlating BMI ratio before and after weight loss with the ratio of total LPC and individual LPC species revealed significant negative relationships of LPC ratios with BMI ratio.

Conclusions

Our findings contribute to the contradictive discussion of the role of LPC in obesity and related chronic inflammation strongly supporting pre-existing data in the literature that show a decrease of LPC species in plasma of obese and a potentially anti-inflammatory role in these subjects.     

Maternal Prepregnancy Body Mass Index and Gestational Weight Gain on Offspring Overweight in Early Infancy

Objective

The aim of the present study was to evaluate the association of maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) with anthropometry in the offspring from birth to 12 months old in Tianjin, China.

Methods

Between 2009 and 2011, health care records of 38,539 pregnant women had been collected, and their children had been measured body weight and length at birth, 3, 6, 9 and 12 months of age. The independent and joint associations of pre-pregnancy BMI and GWG based on the Institute of Medicine (IOM) guidelines with anthropometry in the offspring were examined using General Linear Model and Logistic Regression.

Results

Prepregnancy BMI and maternal GWG were positively associated with Z-scores for birth weight-for-gestational age, birth length-for-gestational age, and birth weight-for-length. Infants born to mothers with excessive GWG had the greatest changes in Z-scores for weight-for-age from birth to Month 3, and from Month 6 to Month 12, and the greatest changes in Z-scores for length-for-age from birth to months 3 and 12 compared with infants born to mothers with adequate GWG. Excessive GWG was associated with an increased risk of offspring overweight or obesity at 12 months old in all BMI categories except underweight.

Conclusions

Maternal prepregnancy overweight/obesity and excessive GWG were associated with greater weight gain and length gain of offspring in early infancy. Excessive GWG was associated with increased infancy overweight and obesity risk.     

Association of Pericardial Fat With Liver Fat and Insulin Sensitivity After Diet‐Induced Weight Loss in Overweight Women

Pericardial adipose tissue (PAT) is positively associated with fatty liver and obesity‐related insulin resistance. Because PAT is a well‐known marker of visceral adiposity, we investigated the impact of weight loss on PAT and its relationship with liver fat and insulin sensitivity independently of body fat distribution. Thirty overweight nondiabetic women (BMI 28.2–46.8 kg/m², 22–41 years) followed a 14.2 ± 4‐weeks low‐calorie diet. PAT, abdominal subcutaneous (SAT), and visceral fat volumes (VAT) were measured by magnetic resonance imaging (MRI), total fat mass, trunk, and leg fat by dual‐energy X‐ray absorptiometry and intrahepatocellular lipids (IHCL) by (¹)H‐magnetic resonance spectroscopy. Euglycemic hyperinsulinemic clamp (M) and homeostasis model assessment of insulin resistance (HOMA_IR) were used to assess insulin sensitivity or insulin resistance. At baseline, PAT correlated with VAT (r = 0.82; P < 0.001), IHCL (r = 0.46), HOMA_IR (r = 0.46), and M value (r = ?0.40; all P < 0.05). During intervention, body weight decreased by ?8.5%, accompanied by decreases of ?12% PAT, ?13% VAT, ?44% IHCL, ?10% HOMA2‐%B, and +24% as well as +15% increases in HOMA2‐%S and M, respectively. Decreases in PAT were only correlated with baseline PAT and the loss in VAT (r = ?0.56; P < 0.01; r = 0.42; P < 0.05) but no associations with liver fat or indexes of insulin sensitivity were observed. Improvements in HOMA_IR and HOMA2‐%B were only related to the decrease in IHCL (r = 0.62, P < 0.01; r = 0.65, P = 0.002) and decreases in IHCL only correlated with the decrease in VAT (r = 0.61, P = 0.004). In conclusion, cross‐sectionally PAT is correlated with VAT, liver fat, and insulin resistance. Longitudinally, the association between PAT and insulin resistance was lost suggesting no causal relationship between the two.     

Impact of Diet‐Induced Weight Loss on the Cardiac Autonomic Nervous System in Severe Obesity

Objective: To determine the impact of diet‐induced weight loss on cardiac autonomic nervous system modulation and arrhythmias in subjects with severe obesity and the influence of a high‐fat or a high‐carbohydrate diet regimen on heart rate variability in reduced‐obese individuals. Research Methods and Procedures: Eight severely obese subjects (BMI ≥ 40.0 kg/m²) underwent a 3‐month weight loss program followed by a 3‐month reduced‐weight maintenance regimen. Thereafter, each subject was admitted for an inpatient period of 17 days on two separate occasions. A high‐carbohydrate (60%) or high‐fat (55%) diet of appropriate energy content for weight maintenance was prescribed during each inpatient phase. Heart rate variability was derived from a 24‐hour Holter monitoring system in all subjects during their inpatient stay. Cardiac Holter monitoring was performed at three occasions (baseline, diet phase I, and diet phase II), including the second night of a two overnight calorimetry chamber stay. Results: After the diet regimen, there was a 10% decrease in weight. There were no significant changes in systolic and diastolic blood pressure, arrhythmias, glucose, insulin, total cholesterol, low‐density lipoprotein‐cholesterol, high‐density lipoprotein‐cholesterol, respiratory exchange ratio, and resting energy expenditure between experiments. Mean heart rate was lower after weight loss compared with baseline (p < 0.001). After weight loss, there was an increase in the parasympathetic indices of heart rate variability showing an increase in cardiac vagal modulation (all p < 0.05). Discussion: Weight loss is associated with significant improvement in autonomic cardiac modulation through enhancement of parasympathetic modulation, which clinically translates into a decrease in heart rate.     

Effects of Sibutramine on Resting Metabolic Rate and Weight Loss in Overweight Women

Sibutramine, a monoamine re-uptake inhibitor, has recently been approved by the Food and Drug Administration as a weight loss agent. Sibutramine lowers body-weight in rodents by reducing energy intake and increasing energy expenditure. Sibutramine facilitates weight loss in human subjects, but it is not clear whether it acts on energy intake, energy expenditure, or both. The present study was a randomized clinical trial designed to assess the effects of sibutramine (at 10 or 30 mg/day) on body weight and resting metabolic rate (RMR). Forty-four overweight women were randomized to 1) placebo (n=15); 2) sibutramine at 10 mg/day (n=15) or, 3) sibutramine at 30 mg/day (n=14). All subjects were instructed to consume a 1200 kcal/day diet for 8 weeks while receiving drug or placebo. RMR was assessed by indirect calorimetry at baseline, at 3 hours after the first dose of drug (or placebo), and at the end of the 8-week weight-loss period. Sibutramine reduced body weight-relative to placebo, but there was no difference between weight loss on the two sibutramine doses. No significant differences in RMR between sibutramine and placebo were seen, either 3-hour post dose or after the 8-week weight-loss period. After the weight loss period, all groups were taken off medication and kept weight stable for another 4 weeks. RMR was measured again and was not different among groups. That there was no change in RMR when sibutramine was stopped further suggests that the drug does not directly affect RMR. In summary, while sibutramine was shown to be an effective weightloss agent over 8 weeks, we found no evidence that it increased RMR.     

Maternal Nicotinamide Riboside Enhances Postpartum Weight Loss,Juvenile Offspring Development,and Neurogenesis of Adult Offspring

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Relationship of Co-Morbidities of Obesity to Weight Loss and Four-Year Weight Maintenance/Rebound

This study examined the effect of weight loss (separate from energy restriction) and weight maintenance/rebound over time on blood pressure, serum lipids, and body composition in 24 obese (mean 137% ideal body weight (IEW)) females with mild to moderate hypertension. Weight loss was induced under tightly controlled General Clinical Research Center conditions until each subject had lost at least 10 kg (mean 13 kg) and attained normal body weight (<120% IBW). After 4 years subjects returned for repeat evaluation. Weight changes were compared with 24 pair-matched normal weight controls who were also followed for 4 years. With weight loss, significant improvements were seen in standing mean arterial pressure (MAP), serum total cholesterol, low-density lipoprotein cholesterol, and triglycerides. Subjects regained 11 kg (87% of the weight lost) over the 4 year follow-up period while control subjects gained only 2 kg. Subjects who chose self-selected exercise gained less weight than nonexercisers (6 kg vs. 13 kg, P<0.05). With weight regain there were significant increases in standing and supine MAP, total cholesterol, and high-density lipoprotein (HDL) cholesterol. The amount of weight regained was significantly correlated with standing MAP (r=0.73), triglycerides (r=0.43), and HDL cholesterol (r=-0.47). The percentage fat of the weight regained was no greater than that of the weight previously lost. Weight loss, distinct from energy restriction, was associated with improvements in blood pressure and serum lipid levels. The ability to sustain these improvements in the co-morbidities of obesity was directly related to the persistence and magnitude of weight loss maintenance.     

Enriched Environment-induced Maternal Weight Loss Reprograms Metabolic Gene Expression in Mouse Offspring

The global prevalence of weight loss is increasing, especially in young women. However, the extent and mechanisms by which maternal weight loss affects the offspring is still poorly understood. Here, using an enriched environment (EE)-induced weight loss model, we show that maternal weight loss improves general health and reprograms metabolic gene expression in mouse offspring, and the epigenetic alterations can be inherited for at least two generations. EE in mothers induced weight loss and its associated physiological and metabolic changes such as decreased adiposity and improved glucose tolerance and insulin sensitivity. Relative to controls, their offspring exhibited improved general health such as reduced fat accumulation, decreased plasma and hepatic lipid levels, and improved glucose tolerance and insulin sensitivity. Maternal weight loss altered gene expression patterns in the liver of offspring with coherent down-regulation of genes involved in lipid and cholesterol biosynthesis. Epigenomic profiling of offspring livers revealed numerous changes in cytosine methylation depending on maternal weight loss, including reproducible changes in promoter methylation over several key lipid biosynthesis genes, correlated with their expression patterns. Embryo transfer studies indicated that oocyte alteration in response to maternal metabolic conditions is a strong factor in determining metabolic and epigenetic changes in offspring. Several important lipid metabolism-related genes have been identified to partially inherit methylated alleles from oocytes. Our study reveals a molecular and mechanistic basis of how maternal lifestyle modification affects metabolic changes in the offspring.