The development of scientific evidence for health policies for obesity: why and how?

Potential obesity-related policy approaches have recently been receiving more attention. Although some have been implemented and others only proposed, few have been formally evaluated. We discuss the relevance, and in some cases irrelevance, of some of the types of evidence that are often brought to bear in considering obesity-related policy decisions. We discuss major methods used to generate such evidence, emphasizing study design and the varying quality of the evidence obtained. Third, we consider what the standards of evidence should be in various contexts, who ought to set those standards, as well as the inherent subjectivity involved in making policy decisions. Finally, we suggest greater transparency from both academics and policymakers in the acknowledgment of subjectivities so they can distinguish and communicate the roles of empirical evidence and subjective values in the formulation of policy.

Hope thinking and past trauma mediate the relationships of body mass index with perceived mental health treatment need and mental health treatment use.

UNLABELLED: Greater body mass is associated with a greater risk of mental health conditions and more frequent mental health treatment use. However, factors that might influence perceived mental health treatment need and mental health treatment use among those of greater weight, including hope thinking, trauma history and perceived mental health treatment stigma, are not well understood. OBJECTIVE: The objective of this study was to determine if hope thinking, trauma history and/or perceived mental health treatment stigma mediate the relationships of body mass index [BMI] with perceived mental health treatment need and mental health treatment use. METHOD: Primary care clinic patients in the Midwest United States (N = 196; BMI range = 18.5 to 47.0, mean = 29.26 ± 6.61, median = 27.90) were recruited to complete a battery of self-report measures that assessed perceived mental health treatment need, mental health treatment use, hope thinking (Trait Hope Scale), trauma history (a single-item traumatic event history screen from the posttraumatic stress disorder module of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), and perceived mental health treatment stigma (Stigma Scale for Receiving Psychological Help). RESULTS: Reduced hope thinking and a greater incidence of past trauma accounted for greater perceived mental health treatment need and greater mental health treatment use among those of greater BMI. BMI was not related to perceived unmet mental health treatment need. CONCLUSION: Increased perceived mental health treatment need and mental health treatment use among those of greater BMI may be explained by lower hope thinking and a greater incidence of trauma in this population. Heavier patients may benefit from interventions designed to augment hope and address traumatic histories.

Randomized controlled trial examining expectancy effects on the accuracy of weight measurement.

BACKGROUND: Researchers and participants' expectations can influence treatment response. Less is known about the effects of researchers' expectations on the accuracy of data collection in the context of a weight loss trial. METHODS: Student raters (N = 58; age = 20.1 ± 2.3 years) were recruited to weigh individuals who they thought were completing a 12-month weight loss trial, although these 'participants' were actually standardized patients (SPs) playing these roles. Prior to data collection, student raters were provided information suggesting that the tested treatment had been effective. Each student rater received a list of 9-10 'participants' to weigh. While the list identified each person as 'treatment' or 'control', this assignment was at random, which allowed us to examine the effects of non-blinding and expectancy manipulation on weight measurement accuracy. We hypothesized that raters would record the weights of 'treatment participants' as lower than those of 'control participants'. RESULTS: Contrary to our hypothesis, raters recorded weights that were 0.293 kg heavier when weighing 'treatment' vs. 'control' SPs, although this difference was not significant (P = 0.175). CONCLUSIONS: This pilot study found no evidence that manipulating expectancies about treatment efficacy or not blinding raters biased measurements. Future work should examine other biases which may be created by not blinding research staff who implement weight loss trials as well as the participants in those trials.

Obesity and mortality: are the risks declining? Evidence from multiple prospective studies in the United States.

We evaluated whether the obesity-associated years of life lost (YLL) have decreased over calendar time. We implemented a meta-analysis including only studies with two or more serial body mass index (BMI) assessments at different calendar years. For each BMI category (normal weight: BMI 18.5 to <25 [reference]; overweight: BMI 25 to <30; grade 1 obesity: BMI 30 to <35; and grade 2-3 obesity: BMI ≥ 35), we estimated the YLL change between 1970 and 1990. Because of low sample sizes for African-American, results are reported on Caucasian. Among men aged ≤60 years YLL for grade 1 obesity increased by 0.72 years (P < 0.001) and by 1.02 years (P = 0.01) for grade 2-3 obesity. For men aged >60, YLL for grade 1 obesity decreased by 1.02 years (P < 0.001) and increased by 0.63 years for grade 2-3 obesity (P = 0.63). Among women aged ≤60, YLL for grade 1 obesity decreased by 4.21 years (P < 0.001) and by 4.97 years (P < 0.001) for grade 2-3 obesity. In women aged >60, YLL for grade 1 obesity decreased by 3.98 years (P < 0.001) and by 2.64 years (P = 0.001) for grade 2-3 obesity. Grade 1 obesity's association with decreased longevity has reduced for older Caucasian men. For Caucasian women, there is evidence of a decline in the obesity YLL association across all ages.

Body mass index and mortality rate among Hispanic adults: a pooled analysis of multiple epidemiologic data sets.

OBJECTIVE: To evaluate the association between body mass index (BMI, kg m⁻²) and mortality rate among Hispanic adults. METHODS AND PROCEDURES: Analysis of five data sets (total N=16,798) identified after searching for publicly available, prospective cohort data sets containing relevant information for at least 500 Hispanic respondents (≥18 years at baseline), at least 5 years of mortality follow-up, and measured height and weight. Data sets included the third National Health and Nutrition Examination Survey, the Puerto Rico Heart Health Program (PRHHP), the Hispanic Established Population for Epidemiologic Studies of the Elderly (HEPESE), the San Antonio Heart Study (SAHS) and the Sacramento Area Latino Study on Aging. RESULTS: Cox proportional hazards regression models, adjusting for sex and smoking, were fit within three attained-age strata (18 to younger than 60 years, 60 to younger than 70 years, and 70 years and older). We found that underweight was associated with elevated mortality rate for all age groups in the PRHHP (hazard ratios [HRs]=1.38-1.60) and the SAHS (HRs=1.88-2.51). Overweight (HRs=0.38 and 0.84) and obesity grade 2-3 (HRs=0.75 and 0.60) associated with reduced mortality rate in the HEPESE dataset for those in the 60 to younger than 70 years, and 70 years and older attained-age strata. Weighted estimates combining the HRs across the data sets revealed a similar pattern. CONCLUSION: Among Hispanic adults, there was no clear evidence that overweight and obesity associate with elevated mortality rate.

Is funding source related to study reporting quality in obesity or nutrition randomized control trials in top-tier medical journals?

BACKGROUND: Faithful and complete reporting of trial results is essential to the validity of the scientific literature. An earlier systematic study of randomized controlled trials (RCTs) found that industry-funded RCTs appeared to be reported with greater quality than non-industry-funded RCTs. The aim of this study was to examine the association between systematic differences in reporting quality and funding status (that is, industry funding vs non-industry funding) among recent obesity and nutrition RCTs published in top-tier medical journals. METHODS: Thirty-eight obesity or nutrition intervention RCT articles were selected from high-profile, general medical journals (The Lancet, Annals of Internal Medicine, JAMA and the British Medical Journal) published between 2000 and 2007. Paired papers were selected from the same journal published in the same year, one with and the other without industry funding. The following identifying information was redacted: journal, title, authors, funding source and institution(s). Then three raters independently and blindly rated each paper according to the Chalmers method, and total reporting quality scores were calculated. FINDINGS: The inter-rater reliability (Cronbach's alpha) was 0.82 (95% confidence interval = 0.80-0.84). The total mean (M) and s.d. of Chalmers Index quality score (out of a possible 100) for industry-funded studies were M = 84.5, s.d. = 7.04 and for non-industry-funded studies they were M = 79.4, s.d. = 13.00. A Wilcoxon matched-pairs signed-ranks test indicates no significant rank difference in the distributions of total quality scores between funding sources, Z = -0.966, P = 0.334 (two tailed). INTERPRETATION: Recently published RCTs on nutrition and obesity that appear in top-tier journals seem to be equivalent in quality of reporting, regardless of funding source. This may be a result of recent reporting of quality statements and efforts of journal editors to raise all papers to a common standard.

Use of self-reported height and weight biases the body mass index-mortality association.

BACKGROUND: Many large-scale epidemiological data sources used to evaluate the body mass index (BMI: kg/m(2)) mortality association have relied on BMI derived from self-reported height and weight. Although measured BMI (BMI(M)) and self-reported BMI (BMI(SR)) correlate highly, self-reports are systematically biased. OBJECTIVE: To rigorously examine how self-reporting bias influences the association between BMI and mortality rate. SUBJECTS: Samples representing the US non-institutionalized civilian population. DESIGN AND METHODS: National Health and Nutrition Examination Survey data (NHANES II: 1976-80; NHANES III: 1988-94) contain BMI(M) and BMI(SR). We applied Cox regression to estimate mortality hazard ratios (HRs) for BMI(M) and BMI(SR) categories, respectively, and compared results. We similarly analyzed subgroups of ostensibly healthy never-smokers. RESULTS: Misclassification by BMI(SR) among the underweight and obesity ranged from 30-40% despite high correlations between BMI(M) and BMI(SR) (r>0.9). The reporting bias was moderately correlated with BMI(M) (r>0.35), but not BMI(SR) (r<0.15). Analyses using BMI(SR) failed to detect six of eight significant mortality HRs detected by BMI(M). Significantly biased HRs were detected in the NHANES II full data set (χ(2)=12.49; P=0.01) and healthy subgroup (χ(2)=9.93; P=0.04), but not in the NHANES III full data set (χ(2)=5.63; P=0.23) or healthy subgroup (χ(2)=1.52; P=0.82). CONCLUSIONS: BMI(SR) should not be treated as interchangeable with BMI(M) in BMI mortality analyses. Bias and inconsistency introduced by using BMI(SR) in place of BMI(M) in BMI mortality estimation and hypothesis tests may account for important discrepancies in published findings.

Kinetics of moisturizing and firming effects of cosmetic formulations.

The assessment of cosmetic efficacy is rarely performed in studies comparing different concentrations of active compounds. The aim of the present study was to determine the skin hydrating and the skin firming dose-response effects of cosmetic formulations enriched in compounds derived from algae and fish collagen. A series of factors were studied including the type of formulation (cream or serum), the concentration in active ingredients, the effect of repetitive applications, as well as any residual effect of the formulations after stopping their applications. The serum enriched in marine compounds showed a better moisturizing effect in short term. The cream appeared more active later, particularly following repeat applications. A sustained tensor (firming) effect was observed during treatment with both the lotion and the cream. However, no remnant firming effect was perceived after stopping treatment.

Putative biases in estimating mortality attributable to obesity in the US population.

BACKGROUND: A recent analysis concluded that there were fewer excess deaths attributable to obesity in the US population than previously believed. This analysis may not have fully corrected for two putative biases, the regression-dilution and the reverse-causation biases. It is not presently known whether correcting for these biases would increase estimates of excess deaths attributable to obesity. METHODS: All-cause mortality hazard ratios (HRs) for different body mass index (BMI) categories were calculated and adjusted for confounding factors, using data from the prospective Atherosclerosis Risk in Communities Study. The analysis was based on 12 457 individuals aged 51-70 years and 606 all-cause deaths during a 5.3-year follow-up. The HRs were corrected for the regression-dilution and reverse-causation biases, and compared with data from a previously published study to evaluate the effects of correcting for these putative biases on estimates of excess deaths attributable to obesity in the US population. RESULTS: The uncorrected all-cause mortality HR for obesity (BMI>/=30) was 1.26 (95% confidence interval (95% CI)=1.01-1.58), using the 21-25 kg/m(2) as ideal-weight category. Correcting for regression dilution increased the HR to 1.46 (95% CI=1.17-1.83). Correcting for both putative biases increased it further to 2.70 (95% CI=1.31-5.57). Such increases in HRs are consonant with increases of several hundred percent in estimates of deaths attributable to obesity in the US. CONCLUSIONS: Correcting for putative biases yielded increases in all-cause mortality HRs for obesity that correspond to substantial increases in estimates of excess deaths attributable to obesity in the US population.

Putative contributors to the secular increase in obesity: exploring the roads less traveled.

OBJECTIVE: To investigate plausible contributors to the obesity epidemic beyond the two most commonly suggested factors, reduced physical activity and food marketing practices. DESIGN: A narrative review of data and published materials that provide evidence of the role of additional putative factors in contributing to the increasing prevalence of obesity. DATA: Information was drawn from ecological and epidemiological studies of humans, animal studies and studies addressing physiological mechanisms, when available. RESULTS: For at least 10 putative additional explanations for the increased prevalence of obesity over the recent decades, we found supportive (although not conclusive) evidence that in many cases is as compelling as the evidence for more commonly discussed putative explanations. CONCLUSION: Undue attention has been devoted to reduced physical activity and food marketing practices as postulated causes for increases in the prevalence of obesity, leading to neglect of other plausible mechanisms and well-intentioned, but potentially ill-founded proposals for reducing obesity rates.

Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update.

Obesity is a major health problem facing the developed and developing world. Efforts by individuals, health professionals, educators, and policy makers to combat the escalating trend of growing obesity prevalence have been multifaceted and mixed in outcome. Various dietary supplements have been marketed to reduce obesity. These products have been suggested to accomplish this by decreasing energy intake and energy absorption, and/or increasing metabolic rate. Ephedra, one such supplement, was banned from sale in the US market because of concerns about adverse events. Another substance, Citrus aurantium, which contains several compounds including synephrine alkaloids, has been suggested as a safe alternative. This review examines the evidence for safety and efficacy of C. aurantium and synephrine alkaloids as examined in animal studies, clinical weight loss trials, acute physiologic studies and case reports. Although at least three reviews of C. aurantium have been published, our review expands upon these by: (i) distinguishing and evaluating the efficacy of C. aurantium and related compounds; (ii) including results from previously unreviewed research; (iii) incorporating recent case reports that serve to highlight, in an anecdotal way, potential adverse events related to the use of C. aurantium and related compounds; and (iv) offering recommendations to guide the design of future trials to evaluate the safety and efficacy of C. aurantium. While some evidence is promising, we conclude that larger and more rigorous clinical trials are necessary to draw adequate conclusions regarding the safety and efficacy of C. aurantium and synephrine alkaloids for promoting weight loss.

Depressive mood and obesity in US adults: comparison and moderation by sex, age, and race.

OBJECTIVE: Sustained depressive mood is a gateway symptom for a major depressive disorder. This paper investigated whether the association between depressive mood and obesity differs as function of sex, age, and race in US adults after controlling for socio-economic variables of martial status, employment status, income level and education level. METHODS: A total of 44,800 nationally representative respondents from the 2001 Behavioral Risk Factor Surveillance Survey were studied. Respondents were classified as having experienced a depressive mood if they felt sad, blue, or depressed at least for 1 week in the previous month. The depressive mood was operationalized in terms of duration and sustenance, both defined based on number of days with depressive mood: 7+ and 14+ days. Age groups were classified as young (18-64 years) and old (65+ years). Obesity status was classified as: not overweight/obese (BMI<25); overweight (25or=30). RESULTS: Prevalence of prior-month depressive mood was 14.3 and 7.8% for 7+ and 14+ days, respectively. Controlling for race and socio-economic variables, both young overweight and obese women were significantly more likely to have experienced depressive mood than nonoverweight/nonobese women. Young overweight, but not obese, men were significantly more likely to have experienced depressive mood than nonoverweight/nonobese men. Young obese women were also significantly more likely to have a sustained depressive mood than nonoverweight/nonobese women. For old respondents, depressive mood and its sustenance were not associated with obesity in either sex. DISCUSSION: The relationship between the depressive mood and obesity is dependent upon gender, age, and race. Young obese women, Hispanics in particular, are much more prone to depressive mood than nonobese women. Future studies testing associations between depression and obesity should be sensitive to the influence of these demographic and socio-economic variables.

A new mutation of the noggin gene in a French Fibrodysplasia ossificans progressiva (FOP) family.

A new mutation of the Noggin gene in a French Fybrodysplasia ossificans progressiva (FOP) family: Fibrodysplasia ossificans progressiva (FOP) is a very rare disease characterized by congenital malformation of the great toes and progressive heterotopic ossification of the muscles. We previously located a FOP gene in the 17q21-22 region and described several mutations of the noggin (NOG) gene (located in 17q22) in four FOP patients, including the G91C mutation which is transmitted dominantly in a Spanish FOP family. We describe in the present study a new mutation of the NOG gene in a French FOP family. This new mutation is a guanine to adenine change at nucleotide 283 (283G --> A) of the NOG gene, and is transmitted in the family (in the heterozygote form) by the affected mother to her two affected children. At the peptide level this mutation (A95T) substitutes an Alanine residue by a Threonine at position 95 of the Noggin protein. The Alanine mutated residue is located just adjacent to the myristoylation site of the protein, where all the mutations we described until now are located.

Haplotypes in the gene encoding protein kinase c-beta (PRKCB1) on chromosome 16 are associated with autism.

Autism is a developmental disorder characterized by impairments in social interaction and communication associated with repetitive patterns of interest or behavior. Autism is highly influenced by genetic factors. Genome-wide linkage and candidate gene association approaches have been used to try and identify autism genes. A few loci have repeatedly been reported linked to autism. Several groups reported evidence for linkage to a region on chromosome 16p. We have applied a direct physical identity-by-descent (IBD) mapping approach to perform a high-density (0.85 megabases) genome-wide linkage scan in 116 families from the AGRE collection. Our results confirm linkage to a region on chromosome 16p with autism. High-resolution single-nucleotide polymorphism (SNP) genotyping and analysis of this region show that haplotypes in the protein kinase c-beta gene are strongly associated with autism. An independent replication of the association in a second set of 167 trio families with autism confirmed our initial findings. Overall, our data provide evidence that the PRKCB1 gene on chromosome 16p may be involved in the etiology of autism.

Obesity and prostate cancer screening in the USA.

OBJECTIVE: To estimate the association between body mass index (BMI: kg/m2) and prostate-specific antigen (PSA) cancer screening in a nationally representative sample of US men aged 50 years and older using data from the 2001 Behavioral Risk Factor Surveillance Survey. RESPONDENTS: Men aged 50 years or older classified by BMI as healthy weight range (18.5-24.9), overweight (25-29.9), obese class I (30-34.9), obese class II (35-39.9), and obese class III (> or =40). OUTCOME MEASURES: Interval since most recent screening for PSA. RESULTS: Adjusting for age, race, smoking, education, employment, income and health insurance status, we found that, compared with men in the healthy weight range, men in the overweight [odds ratio (OR)=1.13; 95% confidence interval (95% CI)=1.04-1.35], obese class I (OR=1.26; 95% CI=1.06-1.36) and obese class II (OR=1.14, 95% CI=1.02-1.26) categories were significantly more likely to have obtained a PSA test within the previous year. A similar pattern was observed when we examined other screening intervals (e.g. within past 2 years, within past 3 years, etc.). CONCLUSIONS: Among men aged 50 years and older, overweight and obesity is associated with obtaining a PSA test.

A novel soy-based meal replacement formula for weight loss among obese individuals: a randomized controlled clinical trial.

OBJECTIVE: To assess the efficacy and safety of a low calorie soy-based meal replacement program for the treatment of obesity. DESIGN: A 12-week prospective randomized controlled clinical trial. SETTING: Outpatient weight control research unit. SUBJECTS: One hundred obese (28

Weight loss causes increased mortality: cons.

Short-term studies indicate that intentional weight loss (IWL) among obese persons significantly improves health variables that are often precursors or markers of chronic diseases (e.g. heart diseases, type-2 diabetes). Hence, it is logical to assume that IWL among obese persons would lead to increased longevity. On the whole, epidemiological studies, including recent ones that use conservative analytic approaches such as distinguishing between apparently IWL and unintentional weight loss (UWL), adjusting for potential confounders and excluding apparently unhealthy subjects, indicate that apparently IWL appears to neither increase nor decrease mortality rate. However, it is important to note that none of the existing studies were designed specifically to test the hypothesis that IWL reduces mortality rate, and given methodological problems, these studies do not provide a satisfactory way to address the body mass index (BMI)-mortality question. Several controlled clinical trials suggest that IWL may reduce mortality rate. However, even in these studies, it is important to acknowledge that subjects are randomized to conditions that produce more or less weight loss and not to distinct levels of weight loss per se. Nevertheless, while we await additional data from better designed studies, given our incomplete knowledge, we conclude that it seems more likely than not that IWL achieved by medically recommended methods does not increase and probably decreases mortality rate.

A meta-analytic investigation of linkage and association of common leptin receptor (LEPR) polymorphisms with body mass index and waist circumference.

METHODS: We analyzed data pooled from nine studies on the human leptin receptor (LEPR) gene for the association of three alleles (K109R, Q223R and K656N) of LEPR with body mass index (BMI; kg/m(2)) and waist circumference (WC). A total of 3263 related and unrelated subjects from diverse ethnic backgrounds including African-American, Caucasian, Danish, Finnish, French Canadian and Nigerian were studied. We tested effects of individual alleles, joint effects of alleles at multiple loci, epistatic effects among alleles at different loci, effect modification by age, sex, diabetes and ethnicity, and pleiotropic genotype effects on BMI and WC. RESULTS: We found that none of the effects were significant at the 0.05 level. Heterogeneity tests showed that the variations of the non-significant effects are within the range of sampling variation. CONCLUSIONS: We conclude that, although certain genotypic effects could be population-specific, there was no statistically compelling evidence that any of the three LEPR alleles is associated with BMI or WC in the overall population.

Identification of three novel mutations of the noggin gene in patients with fibrodysplasia ossificans progressiva.

We report noggin mutations in three Spanish families with fibrodysplasia ossificans progressiva (FOP). The three propositi have typical FOP findings; in the first and third families the parents are unaffected, while in the second family the father is partially affected. DNA of the three propositi and their parents was screened by sequencing for mutations in the noggin gene (NOG). Sequencing indicated a G to C mutation at nucleotide 274 of the NOG gene in the first propositus, encoding for the G92R substitution at the peptide level; this first mutation is de novo, the corresponding change not being observed in parents. In the second propositus, a G to T mutation at nucleotide 271 encodes for the G91C substitution, transmitted in the corresponding family by the partially affected father. In the third propositus, sequencing indicated a G to A mutation at nucleotide 275, encoding for the G92E substitution; this third mutation is de novo. All three mutations, as well as the Delta42 deletion already reported, resulted in the alteration of the portion of the NOG gene at positions 265-282, encoding for the potential N-myristoylation site at residues 89-GGGGGA-94.