The obesity epidemic and changes in self‐report biases in BMI

Objective:

To assess time trends in measurement error of BMI and the sensitivity/specificity of classifying weight status in the United States by analyzing the difference in BMI between self‐reported and measured height and weight.

Design and Methods:

Data from 18,394 respondents aged 20‐89 years from the National Health and Nutrition Examination Survey (NHANES) from 1999 through 2008 were analyzed. Multiple linear regression and logistic regression models estimated trends in reporting bias and misclassification of weight status by BMI categories, sex, age, and racial/ethnic groups, adjusting for the sampling design.

Results:

We find no evidence that there are time trends in the accuracy of self‐report by BMI categories, sex, age, or racial/ethnic groups. The well‐known downward bias in self‐report has remained stable over the last decade; approximately one in six to seven obese individuals were misclassified as nonobese due to underestimation of BMI.

Conclusion:

Increases in obesity rates based on self‐reported height and weight are likely to reflect actual weight increases and are not inflated by changes in reporting accuracy.     

Disability prevalence among healthy weight,overweight, and obese adults

Objective:

Obesity is associated with adverse health outcomes in people with and without disabilities. However, little is known about disability prevalence among people who are obese. The purpose of this study is to determine the prevalence and type of disability among adults who are obese.

Design and Methods:

Pooled data from the 2003‐2009 National Health Interview Survey (NHIS) were analyzed to obtain national prevalence estimates of disability, disability type and obesity. The disability prevalence was stratified by body mass index (BMI): healthy weight (BMI 18.5‐<25.0), overweight (BMI 25.0‐<30.0), and obese (BMI ≥ 30.0).

Results:

In this pooled sample, among the 25.4% of US adults who were obese, 41.7% reported a disability. In contrast, 26.7% of those with a healthy weight and 28.5% of those who were overweight reported a disability. The most common disabilities among respondents with obesity were movement difficulty (32.5%) and work limitation (16.6%).

Conclusions:

This research contributes to the literature on obesity by including disability as a demographic in assessing the burden of obesity. Because of the high prevalence of disability among those who are obese, public health programs should consider the needs of those with disabilities when designing obesity prevention and treatment programs.     

Weight‐Related Terms Differentially Affect Self‐Efficacy and Perception of Obesity

Objective

Little work has explored the effect of weight‐related terms on treatment initiation; only one study has investigated weight‐related terms and the psychological constructs associated with treatment uptake. The present study examines the effects of four common weight‐related terms on treatment initiation and the moderating effect of weight bias internalization.

Methods

Adult participants with overweight and obesity (n = 436) were recruited online and asked to read three vignettes describing clinical encounters; the weight‐related term (i.e., “weight,” “BMI,” “obesity,” or “fat”) was varied randomly. Participants then reported self‐efficacy, cognitive and emotional illness beliefs about obesity (i.e., illness perception), and interest in a weight loss program.

Results

The term “obesity” resulted in the greatest self‐efficacy and perceived control over obesity. “Fat” resulted in the least illness coherence (i.e., understanding of obesity). Weight bias internalization did not moderate the effect of term on self‐efficacy, nor did it moderate illness perception. No differences in weight loss program enrollment were observed.

Conclusions

Use of the term “obesity” may promote patients’ perceived control and self‐efficacy. Use of “fat” should be avoided. Results suggest that, despite patient and clinician preference for euphemistic weight terms, use of clinical language such as “obesity” may perform better in provider intervention.

     

A risk adjusted cost‐effectiveness analysis of alternative models of nurse involvement in obesity management in primary care

Objective:

Controlled evaluations are subject to uncertainty regarding their replication in the real world, particularly around systems of service provision. Using routinely collected data, we undertook a risk adjusted cost‐effectiveness (RAC‐E) analysis of alternative applied models of primary health care for the management of obese adult patients. Models were based on the reported level of involvement of practice nurses (registered or enrolled nurses working in general practice) in the provision of clinical‐based activities.

Design and Methods:

Linked, routinely collected clinical data describing clinical outcomes (weight, BMI, and obesity‐related complications) and resource use (primary care, pharmaceutical, and hospital resource use) were collected. Potential confounders were controlled for using propensity weighted regression analyses.

Results:

Relative to low level involvement of practice nurses in the provision of clinical‐based activities to obese patients, high level involvement was associated with lower costs and better outcomes (more patients losing weight, and larger mean reductions in BMI). Excluding hospital costs, high level practice nurse involvement was associated with slightly higher costs. Incrementally, the high level model gets one additional obese patient to lose weight at an additional cost of $6,741, and reduces mean BMI by an additional one point at an additional cost of $563 (upper 95% confidence interval $1,547).

Conclusion:

Converted to quality adjusted life year (QALY) gains, the results provide a strong indication that increased involvement of practice nurses in clinical activities is associated with additional health benefits that are achieved at reasonable additional cost. Dissemination activities and incentives are required to encourage general practices to better integrate practice nurses in the active provision of clinical services.     

Parental obesity moderates the relationship between childhood appetitive traits and weight

Objective:

In this study, the independent and combined associations between childhood appetitive traits and parental obesity on weight gain from 0 to 24 months and body mass index (BMI) z‐score at 24 months in a diverse community‐based sample of dual parent families (n = 213) were examined.

Design and Methods:

Participants were mothers who had recently completed a randomized trial of weight loss for overweight/obese postpartum women. As measures of childhood appetitive traits, mothers completed subscales of the Children's Eating Behavior Questionnaire, including Desire to Drink (DD), Enjoyment of Food (EF), and Satiety Responsiveness (SR), and a 24‐h dietary recall for their child. Heights and weights were measured for all children and mothers and self‐reported for mothers' partners. The relationship between children's appetitive traits and parental obesity on toddler weight gain and BMI z‐score were evaluated using multivariate linear regression models, controlling for a number of potential confounders.

Results:

Having two obese parents was related to greater weight gain from birth to 24 months independent of childhood appetitive traits, and although significant associations were found between appetitive traits (DD and SR) and child BMI z‐score at 24 months, these associations were observed only among children who had two obese parents. When both parents were obese, increasing DD and decreasing SR were associated with a higher BMI z‐score.

Conclusions:

The results highlight the importance of considering familial risk factors when examining the relationship between childhood appetitive traits on childhood obesity.     

Prediction of measured weight from self‐reported weight was not improved after stratification by body mass index

Objective:

Self‐reported weight may underestimate measured weight. Researchers have tried to reduce the error using statistical models to predict weight from self‐reported weight. We investigate whether deriving equations within separate BMI categories improves the prediction of weight compared with an equation derived regardless of an individual's BMI.

Design and Methods:

The analysis included self‐reported and measured data from 20,536 individuals participating in the EPIC‐Norfolk study. In a derivation set (n = 15,381) two approaches were used to predict weight from self‐reported weight: (1) using a linear regression model with measured weight as outcome and self‐reported weight and age as predictors, and (2) using the same model fit separately within 3 strata defined by BMI (< 25, 25‐30, ≥30 kg m^?2). The performance of these approaches was assessed in a validation set (n = 5,155). Measured weight was compared to self‐reported weight and predicted weight.

Results:

Self‐reported weight underestimated measured weight (P < 0.0001): mean difference ?1.2 ± 3.1 kg (men), ?1.3 ± 2.5 kg (women). Underestimation was greater in obese participants (P < 0.0001). Predicted weight using approach 1 was not significantly different from measured weight (P < 0.05). However, in individuals with BMI < 25 kg m^?2, weight was overestimated in men (0.90 ± 3.87 kg) and women (0.57 ± 2.06 kg), but underestimated in overweight (?0.29 ± 3.58, ?0.20 ± 2.62 kg) and obese (?1.46 ± 5.05 kg, ?0.73 ± 3.54 kg) men and women.

Conclusions:

Using separate prediction equations in strata of BMI did not further improve prediction of weight. In conclusion, predicted weight was closer to measured weight compared with self‐reported weight, but using equations derived in strata of BMI did not further improve the prediction and are not recommended for prediction of weight.

     

A randomized,phase 3 trial of naltrexone SR/bupropion SR on weight and obesity‐related risk factors (COR‐II)

Objective:

To examine the effects of naltrexone/bupropion (NB) combination therapy on weight and weight‐related risk factors in overweight and obese participants.

Design and Methods:

CONTRAVE Obesity Research‐II (COR‐II) was a double‐blind, placebo‐controlled study of 1,496 obese (BMI 30‐45 kg/m²) or overweight (27‐45 kg/m² with dyslipidemia and/or hypertension) participants randomized 2:1 to combined naltrexone sustained‐release (SR) (32 mg/day) plus bupropion SR (360 mg/day) (NB32) or placebo for up to 56 weeks. The co‐primary endpoints were percent weight change and proportion achieving ≥5% weight loss at week 28.

Results:

Significantly (P < 0.001) greater weight loss was observed with NB32 versus placebo at week 28 (?6.5% vs. ?1.9%) and week 56 (?6.4% vs. ?1.2%). More NB32‐treated participants (P < 0.001) experienced ≥5% weight loss versus placebo at week 28 (55.6% vs. 17.5%) and week 56 (50.5% vs. 17.1%). NB32 produced greater improvements in various cardiometabolic risk markers, participant‐reported weight‐related quality of life, and control of eating. The most common adverse event with NB was nausea, which was generally mild to moderate and transient. NB was not associated with increased events of depression or suicidality versus placebo.

Conclusion:

NB represents a novel pharmacological approach to the treatment of obesity, and may become a valuable new therapeutic option.

     

Psychosocial predictors of 4‐year BMI change in overweight and obese children in primary care

Objective:

This study aimed to determine whether (( 1 ) ) initial and/or (( 2 ) ) changes in psychosocial functioning predict body mass index (BMI) z‐score change over 4 years in overweight/mildly obese 5‐ to 9‐year old children presenting to primary care.

Design and Methods:

Eligible participants (n = 258) were overweight/mildly obese children (IOTF criteria) recruited into the LEAP2 trial (ISRCTN52511065) from 3,958 children visiting general practitioners in Melbourne, Australia from May 2005 to July 2006. Predictors were change scores calculated from repeated measures of parent‐ and child‐reported child health‐related quality of life (PedsQL) and self‐esteem; child‐reported desire to be thinner; and parent‐reported child weight concern. Outcome was measured BMI z‐score change from baseline to 4 years.

Results:

The 189 respondents (61% female; 73% retention) showed little mean change in BMI z‐score (?0.08) but wide variation (standard deviation 0.50, range ?1.32 to 1.20). Only one baseline measure (better parent‐reported PedsQL School Functioning) predicted improving BMI z‐score. However, parents and children consistently reported that changes in psychosocial functioning (i.e., PedsQL Social and Global Self‐esteem) were inversely related to BMI z‐score change scores. The strongest predictors of decreases in BMI z‐scores were changes in child‐reported body‐image variables, i.e., improvements in Physical Appearance Self‐esteem (β =0.40, 95% CI ?0.98 to ?0.15, P < 0.01) and declines in Desire to be Thinner (β = 0.33, 95% CI 0.04 to 0.23, P < 0.01).

Conclusions:

At presentation to primary care, it seems unlikely that targeting the psychosocial factors measured in this study would influence BMI z‐score change in overweight/mildly obese children. Subsequent change in psychosocial well‐being covaries with BMI z‐score change and may have important adolescent ramifications; the causal directions for these associations require further research.

     

Preferring thin people does not imply derogating fat people. A rasch analysis of the implicit weight attitude

Objective:

The meaning of the implicit weight attitude in individuals of different weight by distinguishing the contribution of positive and negative associations to the overall measure was investigated.

Design and Methods:

The implicit weight attitude was assessed using the Implicit Association Test. A Rasch model was used to identify which stimuli most affected the implicit measure. Explicit attitudes were assessed with a thin‐fat preference scale, and thermometer scales for both thin and fat people. The sample consists of 510 individuals categorized according to their BMI.

Results and Conclusion:

A significant implicit preference for thin relative to fat people was observed in all weight groups. In normal weight and obese individuals, the preference was mostly affected by positive stimuli (more easily associated with thin than with fat people). In underweight individuals, the preference was mostly guided by positive (more easily associated with thin than with fat people) and negative (more easily associated with fat than with thin people) stimuli. In overweight individuals, all stimuli contributed to the preference in a similar way. In all weight groups, the implicit weight attitude correlated with the explicit preference and/or the thin thermometer, whereas it never correlated with the fat thermometer. A pro‐thin bias was observed in normal weight and obese individuals, whereas both a pro‐thin and an anti‐fat bias were observed in underweight individuals. A clear preference for thin people relative to fat people was observed in overweight individuals. Therefore, uncritically interpreting the implicit preference for thin people as a sign of derogating fat people might be misleading.     

Insurer and employer views on pediatric obesity treatment: A qualitative study

Objective:

The effectiveness of group‐based comprehensive, multidisciplinary (stage 3) pediatric weight management programs is backed by a growing body of literature, yet insurance coverage of these programs is scarce to nonexistent, limiting their reach and long‐term survival. The objective of this study was to better understand the perspectives of insurers and large employers on the issue of group‐based treatment coverage.

Design and Methods:

The authors performed a qualitative study utilizing structured interviews with these stakeholders, following accepted techniques.

Results:

Six major themes emerged: cost, program effectiveness, corporate social responsibility, secondary parental (employee) benefits, coverage options and new benefit determination.

Conclusion:

Future efforts to secure payment for group‐based pediatric weight management programs should address these key themes.     

Sleep duration and weight change in midlife women: The SWAN sleep study

Objective:

Short sleep duration has been associated with higher current BMI and subsequent weight gain. However, most prior longitudinal studies are limited by reliance on self‐reported sleep duration, and none accounted for the potential confounding effect of sleep‐disordered breathing. The associations of sleep duration with current BMI and BMI change were examined among 310 midlife women in the Study of Women's Health Across the Nation (SWAN) Sleep Study (2003‐2005).

Methods:

Sleep duration was assessed for approximately one month with concurrent wrist actigraphy and sleep diaries. The presence and severity of sleep‐disordered breathing was quantified using the apnea‐hypopnea index (AHI) based on in‐home polysomnography. BMI was assessed annually through core SWAN visit 10 (2006 and 2008).

Results:

Mean BMI increased from 29.6 (SD = 7.8) kg/m² to 30.0 (SD = 8.0) kg/m² over an average of 4.6 years (SD = 1.0) of follow‐up. In cross‐sectional analyses controlling for AHI, demographic variables, and several potential confounding variables, actigraphy (estimate = ‐1.22, 95% confidence interval (CI): ‐2.03, ‐0.42) and diary (estimate = ‐0.86, 95% CI ‐1.62, ‐0.09) measures of sleep duration were inversely associated with BMI. Each hour of less sleep was associated with 1.22 kg/m² greater BMI for actigraphy sleep duration, and a 0.86 kg/m² greater BMI for diary sleep duration. Longitudinal associations between sleep duration and annual BMI change were nonsignificant in unadjusted and fully adjusted models.

Conclusion:

In this cohort of midlife women, cross‐sectional associations between sleep duration and current BMI were independent of sleep‐disordered breathing, but sleep duration was not prospectively associated with weight change.     

The use of routine thoracoabdominal CT scans in the polytrauma patient to estimate obesity

Objective:

To utilize data from routine CT scans to quantify obesity in polytrauma patients without the need to obtain a height and weight.

Design and Methods:

We utilized a comprehensive database including multidetector CT thoracoabdominal images of all polytrauma patients admitted to a Level 1 trauma center. One thousand one hundred seventy‐four patients were reviewed from 2006 to 2008 and of these, 162 had previous documentation of Body Mass Index (BMI) or height and weight measurements as an outpatient within 6 months of trauma activation and with a truncal girth smaller than the scanning area of the CT machine. Truncal Adiposity Volume (TAV) was calculated from three dimensional reconstructions (3DRs) of the CT scans of the thorax and abdomen obtained in the emergency department.

Results:

Statistical analysis yielded a fairly good correlation between TAV and BMI (correlation coefficient = 0.77; p‐value < 0.0001). The intra‐observer and inter‐observer correlations in measuring TAV were high; 0.99 and 0.98 respectively. A linear regression equation of BMI on TAV was estimated and it had a form: 3DR BMI = 20.81+0.00064×TAV. In conclusion, TAV provides a reproducible means of evaluating obesity in trauma patients from routinely obtained CT scans.

Conclusions:

The TAV eliminates the often problematic task of obtaining a height and weight in a trauma patient and it correlates fairly well with the most commonly used clinical method of quantifying patient adiposity, BMI. This method may provide a more direct measurement of adiposity than does BMI, and holds promise for improving trauma care and research in the obese patient.     

Obesity and the occurrence of bronchitis in adolescents

Objective:

Previous studies have shown that an elevated BMI was associated with higher risks of bronchitis among children. The magnitude of how increase in BMI influencing the risk of incident bronchitis remained unexplored. The objective of this study is to assess the association between BMI and the incidence of bronchitis in the Taiwan Children Health Study.

Design:

A school‐based prospective cohort study.

Methods:

We conducted a population‐based prospective cohort study among seventh‐grade school children in 14 Taiwanese communities. A total of 3,634 adolescents completed follow‐up questionnaire in 2009. Associations between BMI and incident bronchitis were analyzed by multiple Poisson regression models, taking overdispersion into account.

Results:

Among eligible cohort participants without bronchitis at study entry, the proportion of overweight and obesity were 32.1% and 17.9%. Overweight was 40.7% and obesity was 27.7% among those with incident bronchitis. The BMI percentile categories showed significant increasing trends for bronchitis in total eligible children and in girls (P for trend <0.001). Overweight and obesity were both associated with increased risks of incident bronchitis. This association was significant in girls only while stratified by gender.

Conclusions:

Our data showed that the BMI percentile and weight status were associated with higher risks of incident bronchitis in adolescents, especially in girls.     

Placental weight mediates the effects of prenatal factors on fetal growth: the extent differs by preterm status

Objective:

Elevated pre‐pregnancy BMI, excessive gestational weight gain (GWG), and gestational diabetes mellitus (GDM) are known determinants of fetal growth. The role of placental weight is unclear. We aimed to examine the extent to which placental weight mediates the associations of pre‐pregnancy BMI, GWG, and GDM with birth weight‐for‐gestational age, and whether the relationships differ by preterm status.

Design and Methods:

We examined 1,035 mother‐infant pairs at birth from the Boston Birth Cohort. Data were collected by questionnaire and clinical measures. Placentas were weighed without membranes or umbilical cords. We performed sequential models excluding and including placental weight, stratified by preterm status.

Results:

We found that 21% of mothers were obese, 42% had excessive GWG, and 5% had GDM. Forty‐one percent were preterm. Among term births, after adjustment for sex, gestational age, maternal age, race, parity, education, smoking, and stress during pregnancy, birth weight‐for‐gestational age z‐score was 0.55 (0.30, 0.80) units higher for pre‐pregnancy obesity vs. normal weight. It was 0.34 (0.13, 0.55) higher for excessive vs. adequate GWG, 0.67 (0.24, 1.10) for GDM vs. no DM, with additional adjustment for pre‐pregnancy BMI. Adding placental weight to the models attenuated the estimates for pre‐pregnancy obesity by 20%, excessive GWG by 32%, and GDM by 21%. Among preterm infants, GDM was associated with 0.67 (0.34, 1.00) higher birth weight‐for‐gestational age z‐score, but pre‐pregnancy obesity and excessive GWG were not. Attenuation by placental weight was 36% for GDM.

Conclusions:

These results suggest that placental weight partially mediates the effects of pre‐pregnancy obesity, GDM, and excessive GWG on fetal growth among term infants.     

Differences in motivations and weight loss behaviors in young adults and older adults in the national weight control registry

Objective:

The goal of this study was to compare young adults (YA) and older adults (OA) in the National Weight Control Registry on motivations for weight loss and weight‐loss behaviors.

Design and Methods:

Participants (n = 2,964, 82% female, 94% White, BMI = 24.8 ± 4.4) were divided into two age groups (18‐35 vs. 36‐50) and compared on motivations, strategies for weight loss, diet, physical activity (PA), and the three‐factor eating questionnaire.

Results:

YA were 28.6% of the sample (n = 848). YA and OA achieved similar weight losses (P = 0.38), but duration of maintenance was less in YA (43 vs. 58 months, P < 0.001). YA were more likely to cite appearance and social motivations for weight loss, were less motivated by health, and were less likely to report a medical trigger for weight loss (P's < 0.001). YA were more likely to use exercise classes and to lose weight on their own, and less likely to use a commercial program (P's < 0.001). YA reported engaging in more high‐intensity PA (P = 0.001). There were no group differences in total calories consumed (P = 0.47), or percent calories from fat (P = 0.97), alcohol (P = 0.52), or sugar‐sweetened beverages (P = 0.26).

Conclusions:

YA successful weight losers (SWL) are motivated more by appearance and social influences than OA, and physical activity appears to play an important role in their weight‐loss efforts. The differences reported by YA and OA SWL should be considered when developing weight‐loss programs for YA.     

Phase II Feasibility Study of a Weight Loss Intervention in Female Breast and Colorectal Cancer Survivors (SWOG S1008)

Objective

This study aimed to test the feasibility of a 12‐month weight loss intervention using telephone‐based counseling plus community‐situated physical activity (PA) in female breast cancer (BC) and colorectal cancer (CRC) survivors.

Methods

This multisite cooperative group study enrolled sedentary, female, postmenopausal BC and CRC survivors with BMI ≥ 25 kg/m² to receive 12‐month fitness center memberships and telephone counseling encouraging 150 min/wk of PA and a 500‐kcal/ddecrease in energy intake. Feasibility criteria included accrual, adherence, and retention. Target weight loss was ≥ 5%.

Results

Among 25 BC survivors, median baseline BMI was 37.2 (range: 27.7‐54.6), accrual occurred in 10 months, 60% and 28% met diet and exercise goals, 80% provided 12‐month measures, and average weight loss was 7.6% (95% CI: ?3.9%, 19.2%). Among 23 CRC survivors, median BMI was 31.8 (range: 26.4‐48.7), accrual occurred in 24 months, 61% and 17% met diet and exercise goals, 87% provided measures, and average weight loss was 2.5% (95% CI: ?8.2%, 13.3%).

Conclusions

It is feasible to recruit and retain BC survivors in a cooperative group diet and PA weight loss trial. BC survivors achieved clinically meaningful weight loss but did not meet a priori adherence goals. In CRC survivors, recruitment was more difficult, and the intervention was less effective.

     

Two‐Year Changes in Child Weight Status,Diet, and Activity by Neighborhood Nutrition and Physical Activity Environment

Objective

The aim of this study was to examine 2‐year changes in weight status and behaviors among children living in neighborhoods differing on nutrition and activity environments.

Methods

A prospective observational study, the Neighborhood Impact on Kids study, was conducted in King County, Washington, and San Diego County, California. Children 6 to 12 years old and a parent or caregiver completed Time 1 (n = 681) and Time 2 (n = 618) assessments. Children lived in neighborhoods characterized as “high/favorable” or “low/unfavorable” in nutrition and activity environments, respectively (four neighborhood types). Child BMI z score and overweight or obesity status were primary outcomes, with diet and activity behaviors as behavioral outcomes.

Results

After adjusting for sociodemographics and Time 1 values, children living in two of the three less environmentally supportive neighborhoods had significantly less favorable BMI z score changes (+0.11, 95% CI: 0.01‐0.21; + 0.12, 95% CI: 0.03‐0.21), and all three less supportive neighborhoods had higher overweight or obesity (relative risks, 1.41‐1.49; 95% CI: 1.13‐1.80) compared with children in the most environmentally supportive neighborhoods. Changes in daily energy intake and sedentary behavior by neighborhood type were consistent with observed weight status changes, with unexpected findings for physical activity.

Conclusions

More walkable and recreation‐supportive environments with better nutrition access were associated with better child weight outcomes and related behavior changes.     

How best to use partial meal replacement in managing overweight or obese patients with poorly controlled type 2 diabetes

Objective:

To compare patient compliance and benefits, over 12 months, of 1 versus 2 partial meal replacement (PMR) for the management of overweight/obese subjects with inadequately controlled type 2 diabetes.

Design and Methods:

Thirty‐six overweight patients with inadequately controlled type 2 diabetes (BMI > 27 kg/m² and HbA1c > 7.5% [58 mmol/mol]) were randomized to receive 1 or 2 PMR/day, while maintaining usual lifestyle. Subjects were seen monthly and adjustment of medications was made to prevent hypoglycemia. Compliance was assessed by counting unused sachets.

Results:

Patients on 2 PMR/day lost almost 4 kg compared with only 0.5 kg in the 1 PMR/day group. This difference was statistically significant (P < 0.05). Overall PMR was about 30% as effective as in our previous study on total meal replacement. Reductions in weight, waist, and HbA1c were better in the 2 PMR/day group while patient dropout and compliance were not worse over a 12‐month period.

Conclusion:

PMR provides a further management option for overweight/obese individuals with type 2 diabetes. The initial recommendation should be 2 PMR/day.     

Meta‐analysis of the association between body mass index and health‐related quality of life among adults,assessed by the SF‐36

Objective:

Obesity is associated with impaired overall health‐related quality of life but individual studies suggest the relationship may differ for mental and physical quality of life. A systematic review using Medline, Embase, PsycINFO and ISI Web of Knowledge, and random effects meta‐analysis was undertaken.

Design and Methods:

Studies were included in the meta‐analysis if they were conducted on adults (defined as age >16 years), reported an overall physical and mental component score of the SF‐36, and, or both. Heterogeneity was assessed using I² statistics and publication and small study biases using funnel plots and Egger's test. Between‐study heterogeneity was explored using meta‐regression.

Results:

Eight eligible studies provided 42 estimates of effect size, based on 43,086 study participants. Adults with higher than normal body mass index had significantly reduced physical quality of life with a clear dose‐response relationship across all categories. Among class III obese adults, the score was reduced by 9.72 points (95% Confidence Interval 7.24, 12.20, P < 0.001). Mental quality of life was also significantly reduced among class III obese (?1.75, 95% confidence interval ?3.33, ?0.16, P = 0.031), but was not significantly different among obese (class I and class II) individuals, and was significantly increased among overweight adults (0.42, 95% confidence interval 0.17, 0.67, P = 0.001), compared to normal weight individuals. Heterogeneity was high in some categories, but there was no significant publication or small study bias.

Conclusions:

Different patterns were observed for physical and mental HRQoL, but both were impaired in obese individuals. This meta‐analysis provides further evidence on the impact of obesity on both aspects of health‐related quality of life.

     

Concordance of BAI and BMI with DXA in the Newfoundland Population

Background:

Body adiposity index (BAI), indirect method proposed to predict adiposity, was developed using Mexican Americans and very little data are available regarding its validation in Caucasian populations to date.

Objective:

The study objectives were to validate the BAI with dual‐energy X‐ray absorptiometry (DXA) body fat percentage (%BF), taking into consideration the gender and adiposity status.

Design and Methods:

A total of 2,601 subjects (Male 662, Female 1939) from our Complex Diseases in the Newfoundland population: Environment and Genetics (CODING) study participated in this investigation. Pearson correlations, with the entire cohort along with men and women separately, were used to compare the correlation of both BAI and BMI with %BF. Additionally, the concordance between BAI and BMI with %BF were also performed among normal‐weight (NW), overweight (OW), and obese (OB) groups. Adiposity status was determined by the Bray Criteria according to DXA %BF.

Results:

BAI performs better than BMI in our Caucasian population by: (1) reflecting the gender difference in total %BF between women and men, (2) correlating better with DXA %BF than BMI when women and men are combined, and (3) performing better in NW and OW subjects for both the sexes. However, BAI performs less effectively than BMI in OB men and women.

Conclusion:

In summary, the BAI method is a better estimate of adiposity than BMI in non‐OB subjects in our Caucasian population. A measurement sensitive to the changes in adiposity for both men and women is suggested to be incorporated into the present BAI equation to increase accuracy.