The trend of mean BMI values of US adults, birth cohorts 1882-1986 indicates that the obesity epidemic began earlier than hitherto thought

Food environment and obesity: a systematic review and meta-analysis

Background

Obesity is influenced by a complex, multifaceted system of determinants, including the food environment. Governments need evidence to act on improving the food environment. The aim of this study was to review the evidence from spatial environmental analyses and to conduct the first series of meta-analyses to assess the impact of the retail food environment on obesity.

Methods

We performed a systematic review and random-effects meta-analyses, focusing on geographical-statistical methods to assess the associations between food outlet availability and obesity. We searched OvidSP-Medline, Scielo, Scopus and Google Scholar databases up to January 2022. The search terms included spatial analysis, obesity and the retail food environment. Effect sizes were pooled by random-effects meta-analyses separately according to food outlet type and geographical and statistical measures.

Findings

Of the 4118 retrieved papers, we included 103 studies. Density (n=52, 50%) and linear and logistic regressions (n=68, 66%) were the main measures used to assess the association of the food environment with obesity. Multilevel or autocorrelation analyses were used in 35 (34%) studies. Fast-food outlet proximity was positively and significantly associated with obesity (OR: 1.15, 95% CI: 1.02 to 1.30, p=0.02). Fresh fruit and vegetable outlet density and supermarket proximity were inversely associated with obesity (OR: 0.93, 95% CI: 0.90 to 0.96, p<0.001; OR: 0.90, 95% CI: 0.82 to 0.98, p=0.02). No significant associations were found for restaurants, convenience stores or any of the body mass index measures.

Conclusions

Food outlets which sell mostly unhealthy and ultra-processed foods were associated with higher levels of obesity, while fruit and vegetable availability and supermarket accessibility, which enable healthier food access, were related to lower levels of obesity. The regulation of food outlets through zoning laws may not be enough to tackle the burden of obesity. Regulations that focus on increasing the availability of healthy food within stores and ensure overall healthy food environments require further attention.

PROSPERO registration number

CRD42018111652.

Trends in Obesity-Related Mortality and Racial Disparities

BACKGROUND

Across the globe, obesity stands as a prominent public health concern, linked to a heightened susceptibility to a range of metabolic and cardiovascular disorders. This study reveals a disproportionate impact of obesity on African American (AA) communities, irrespective of socioeconomic status. Structural racism plays a critical role in perpetuating healthcare disparities between AA and other racial/ethnic groups in the United States. These disparities are reflected in limited access to nutritious food, safe exercise spaces, health insurance, and medical care, all of which significantly influence healthcare outcomes and obesity prevalence. Additionally, both conscious and unconscious interpersonal racism adversely affect obesity care, outcomes, and patient-healthcare provider interactions among Blacks.

STUDY OBJECTIVE

This study aims to analyze and compare obesity-related mortality rates among AAs, Whites, and other racial groups.

METHODOLOGY

We queried the CDC WONDER dataset, incorporating all US death certificates. During data extraction, various ICD 10 codes were used to denote different obesity categories: E66.1 (drug-induced obesity), E66.2 (severe obesity with alveolar hypoventilation), E66.3 (overweight), E66.8 (other forms of obesity), E66.9 (unspecified obesity), E66.0 (obesity due to excess calorie intake), E66.01 (severe obesity due to excess calories), and E66.09 (other forms of obesity caused by excess calorie intake). Our study encompassed decedents aged ≥15 years, with obesity-related diseases as the underlying cause of death from 2018 to 2021. Sex- and race-specific obesity-related mortality rates were examined for AAs, Whites, and other races. Resultant mortality trends were computed and presented as ratios comparing AA and White populations.

RESULTS

This study reveals lower obesity-related mortality rates in AAs compared to Whites. Furthermore, women exhibited higher rates than men. In the 15 to 24 age bracket, males comprised 60.11% of the 361 deaths, whereas females made up 39.89%. In this demographic, 35.46% of deaths were among Blacks, with 64.54% among Whites. Within the 25 to 34 age group, females constituted 37.26% of the 1943 deaths, and males 62.74%. Whites made up 62.94% of the fatalities, Blacks 33.40%, with other racial groups accounting for the remainder. These trends extended through the 35-44, 45-54, 55-64, 65-74, and 75+ age categories, with variations in death proportions among genders and races. Whites consistently accounted for the highest death percentages across all age groups, followed by Blacks. Our data indicate that obesity-related mortality tends to occur earlier in life.

CONCLUSION

Our results corroborate previous studies linking elevated mortality risk to obesity and overweight conditions. The uniformity of our findings across age groups, as well as genders, supports the proposal for applying a single range of body weight throughout life. Given the ongoing rise in obesity and overweight conditions across the United States, excess mortality rates are projected to accelerate, potentially leading to decreased life expectancy. This highlights the urgency for developing and implementing effective strategies to control and prevent obesity nationwide.

Obesity and labour market outcomes in Italy: a dynamic panel data evidence with correlated random effects

This paper investigates the effects of obesity, socio-economic variables, and individual-specific factors on work productivity across Italian regions. A dynamic panel data with correlated random effects is used to jointly deal with incidental parameters, endogeneity issues, and functional forms of misspecification. Methodologically, a hierarchical semiparametric Bayesian approach is involved in shrinking high dimensional model classes, and then obtaining a subset of potential predictors affecting outcomes. Monte Carlo designs are addressed to construct exact posterior distributions and then perform accurate forecasts. Cross-sectional Heterogeneity is modelled nonparametrically allowing for correlation between heterogeneous parameters and initial conditions as well as individual-specific regressors. Prevention policies and strategies to handle health and labour market prospects are also discussed.

Weight gain is associated with shorter lifespan: a longitudinal study of New Zealand soldiers serving in both world wars

Obesity is an increasing public health concern with important mortality consequences. Weight gain or maximum adult BMI, not BMI at one point in time, has been shown to be an important risk factor in cohorts studied recently during an era of rapid increase in population levels of overweight and obesity. However, there is limited evidence on individual weight trajectories from cohorts born before the mid-twentieth century. Archival world war military personnel files from New Zealand are freely available online, and identify service in both wars. A pilot study of 316 soldiers confirmed the files contain sufficient information to examine health trajectories and lifespan. Because this cohort are now entirely deceased, nearly the entire sample can be found in death records to estimate the impact of weight increases on lifespan. Weight change over 20-30 years and its relationship with lifespan is examined using ordinary least squares regression. The study demonstrates that military records are a feasible source for collecting data on adult weight and health trajectories in the first half of the twentieth century. Although this sample is likely to be composed of men fitter than average, there is a clear pattern of increasing weight from early to mid-adulthood. Weight gain from early adulthood to middle-age was found to be more strongly associated with mortality than weight in early adulthood. A one unit increase in BMI over the inter-war period was found to be associated with an 8 month decline in lifespan. These results confirm that weight gain in adulthood has an important impact on mortality in an earlier birth cohort than previously studied, and that data exist to measure any changes more precisely over time.

Obesity among African American people in the United States: A review

Obesity is a growing public health crisis in the United States and is associated with a substantial disease burden due to an increased risk for multiple complications, including cardiovascular and metabolic diseases. As highlighted in this review, obesity disproportionately affects the African American population, women in particular, regardless of socioeconomic status. Structural racism remains a major contributor to health disparities between African American people and the general population, and it limits access to healthy foods, safe spaces to exercise, adequate health insurance, and medication, all of which impact obesity prevalence and outcomes. Conscious and unconscious interpersonal racism also impacts obesity care and outcomes in African American people and may adversely affect interactions between health care practitioners and patients. To reduce health disparities, structural racism and racial bias must be addressed. Culturally relevant interventions for obesity management have been successfully implemented that have shown benefits in weight management and risk-factor reduction. Strategies to improve health care practitioner-patient engagement should also be implemented to improve health outcomes in African American people with obesity. When managing obesity in African American people, it is critical to take a holistic approach and to consider an individual's social and cultural context in order to implement a successful treatment strategy.

The mortality risk of being overweight in the twentieth century: Evidence from two cohorts of New Zealand men

How have health and social mortality risks changed over time? Evidence from pre-1945 cohorts is sparse, mostly from the United States, and evidence is mixed on long-term changes in the risk of being overweight. We develop a dataset of men entering the NZ army in the two world wars, with objectively measured height and weight, and socioeconomic status in early adulthood. Our sample includes significant numbers of indigenous Māori, providing estimates of weight and mortality risk in an indigenous population. We follow men from war's end until death, with data on more than 12,000 men from each war. Overweight and obesity were important risk factors for mortality, and associated with shorter life expectancy. However, the reduction in life expectancy associated with being overweight declined from 5 to 3 years between the two cohorts, consistent with the hypothesis that being overweight became less risky during the twentieth century.

Moral foundations tracked over 200 years of lexicographic data, and their predictors

The prediction that reduction of negative selection decreases group-level competitiveness, as reflected in increased individual-focused and diminished group-focused moral foundations, is tested. To measure this hypothesized shift in moral foundations, we conduct a culturomic analysis of the utilization frequencies of items sourced from the moral foundations item pool, tracked among Britannic populations from 1800 to 1999 using Google Ngram Viewer. The resultant higher-order factor, which tracks increasing individualizing values and decreasing binding values, is termed Asabiyyah (capturing social cohesion and collective purpose). Two predictors of this factor are examined: change in the strength of intergroup competition and change in levels of indicators of developmental instability. Both the strength of intergroup competition and levels of developmental instability associate with Asabiyyah. Rising developmental instability mediates the impact of inter-group competition, indicating that reduced between-group competition might have relaxed negative selection against mutations, which might reduce Asabiyyah via their effects on inter-genomic transactions. These results must be interpreted carefully, given the clear real-world evidence that explicit commitment to group-oriented values often features in harmful and maladaptive social and political ideologies of an extreme character.

Risk of diabetes in haemophilia patients compared to clinic and non-clinic control cohorts

INTRODUCTION

Ageing patients with haemophilia (PWH) develop cardiovascular risk factors impacting care. Little is known about the prevalence of diabetes in PWH and its relation to other comorbidities.

AIM

To examine the risk of diabetes for adult PWH compared to men from the general United States population (National Health and Nutrition Examination Surveys [NHANES]) and outpatients attending a Veterans Affairs Medical Center (VAMC) clinic.

METHODS

Retrospective cross-sectional design. PWH from four haemophilia centres (n = 690) were matched with random samples from NHANES and VAMC. Diabetes (yes/no) was the outcome, while age, body mass index (BMI), race and Hepatitis C (HCV; by serology) and human immunodeficiency virus (HIV) positivity were covariates. We fitted semiparametric generalized additive models (GAMs) in order to compare diabetes risk between cohorts.

RESULTS

Younger PWH were at lower risk of diabetes than NHANES or VAMC subjects irrespective of BMI. However, the risk of diabetes rose in older PWH and was closely associated with HCV. For HCV-negative subjects, the risk of diabetes was considerably lower for PWH than NHANES and VAMC subjects. The difference persisted after controlling for BMI and age, indicating that the low risk of diabetes in PWH cannot be explained by lean body mass alone.

CONCLUSION

Since many ageing PWH are HCV positive and therefore at heightened risk for diabetes, it is important to incorporate diabetes screening into care algorithms in Haemophilia Treatment Centers, especially since PWH are not always followed in primary care clinics.

The future of human malnutrition: rebalancing agency for better nutritional health

The major threat to human societies posed by undernutrition has been recognised for millennia. Despite substantial economic development and scientific innovation, however, progress in addressing this global challenge has been inadequate. Paradoxically, the last half-century also saw the rapid emergence of obesity, first in high-income countries but now also in low- and middle-income countries. Traditionally, these problems were approached separately, but there is increasing recognition that they have common drivers and need integrated responses. The new nutrition reality comprises a global ‘double burden’ of malnutrition, where the challenges of food insecurity, nutritional deficiencies and undernutrition coexist and interact with obesity, sedentary behaviour, unhealthy diets and environments that foster unhealthy behaviour. Beyond immediate efforts to prevent and treat malnutrition, what must change in order to reduce the future burden? Here, we present a conceptual framework that focuses on the deeper structural drivers of malnutrition embedded in society, and their interaction with biological mechanisms of appetite regulation and physiological homeostasis. Building on a review of malnutrition in past societies, our framework brings to the fore the power dynamics that characterise contemporary human food systems at many levels. We focus on the concept of agency, the ability of individuals or organisations to pursue their goals. In globalized food systems, the agency of individuals is directly confronted by the agency of several other types of actor, including corporations, governments and supranational institutions. The intakes of energy and nutrients by individuals are powerfully shaped by this ‘competition of agency’, and we therefore argue that the greatest opportunities to reduce malnutrition lie in rebalancing agency across the competing actors. The effect of the COVID-19 pandemic on food systems and individuals illustrates our conceptual framework. Efforts to improve agency must both drive and respond to complementary efforts to promote and maintain equitable societies and planetary health.

Protein-Rich Diets for Weight Loss Maintenance

PURPOSE OF REVIEW

High-protein diets in the management of obesity have been around for many years and have been rigorously tested for their ability to induce weight loss. Comparably less is known about their effects on the maintenance of lost weight.

RECENT FINDINGS

Several small and a few large randomized trials have evaluated the efficacy of high-protein diets (20-35% of calories from protein; 1.2-1.9 g/kg∙day) compared with normal-protein diets (10-20% of calories from protein; 0.8-1.3 g/kg∙day), consumed mostly ad libitum during weight loss maintenance, i.e., after clinically significant weight loss. Most of these studies indicate that weight regain in the short term (3-12 months) is lower by 1-2 kg with high-protein diets than low-protein diets. This effect is attenuated with longer periods of observation, likely because of decreasing dietary compliance. In line with findings during the active weight loss phase, studies assessing the efficacy of protein-rich diets to improve weight loss maintenance report beneficial effects in the short term, which nevertheless dissipate over time.

Filling the weight gap: Estimating body weight and BMI using height, chest and upper arm circumference of Swiss conscripts in the first half of the 20th century

We estimate weight and BMI values based on height, chest circumference, and mid upper arm circumference measures of Swiss conscripts in the city of Zurich for each year between 1904 and 1932. Height, chest circumference, and mid upper arm circumference were measured each year from 1904 to 1951. Body weight is available from 1933 to 1951. We used prediction equations from the literature, and also developed our own equations, which we tested and validated on the dataset from 1933 to 1951. We used a representative sample of usually 19-year-old Swiss males (N = 88,792, coverage > 88 %). There was an increase in average height and chest circumference between 1904 and 1951. During both world wars, chest circumference, mid upper arm circumference, weight, and BMI decreased, while height stagnated. Overall mean weight and BMI increased from 1904 to 1951, but decreased during the Great Depression. After World War II, weight quickly returned to the pre-war and pre-Great Depression level, while BMI had not reached the 1933 level by 1951. Average weights of the lower and middle socioeconomic groups were catching up with average weight of the upper socioeconomic group from 1904 to 1951. The convergence in height is less pronounced. Finally, we show that it is possible to accurately predict mean weight and BMI from other anthropometric measurements. We suggest that our estimation approach could be replicated for other historical populations to obtain more information on how nutritional status changed over time.

How does body mass index affect economic growth? A comparative analysis of countries by levels of economic development

The WHO views obesity as a significant risk to population health. Evidence suggests that obesity reduces labor-market attachment, worker productivity, and earnings. This link at the micro level may translate into adverse effects on economic growth at the macro level. Few studies have evaluated how body mass index impacts economic growth across and within countries. This sparse evidence base reflects the lack of consistent data across a broad spectrum of countries and timespan, as well as the empirical difficulties in bypassing endogeneity bias relating to unobserved selection and potential reverse causality between bodyweight and GDP. We address both of these challenges by first assembling a comprehensive panel of data spanning 116 countries over 25 years (1984-2008), and then presenting, to the best of our knowledge, the first empirical study of economic growth and obesiy correcting for endogeneity. Our GMM estimates indicate that, in developed countries, a higher level of BMI has direct negative effects on economic growth in a fully saturated model that controls for levels of human capital. In particular, we predict that the increase in BMI over the time period of analysis may have reduced potential economic growth over this period by between 3.5-5.8 percentage points.

Peer effects of obesity on child body composition

This study investigates whether peer obesity is a driver of individual weight changes in public school children and whether the impact of peer effects changes as children age. Quantifying peer effects is important for understanding the social determinants of obesity and for planning effective school wellness policies. However, the extant empirical research on peer effects is limited due to difficulties in separating causal influences from confounding factors. This study overcomes some of these difficulties by using a within-school, across-cohort empirical design to separate confounding factors at the individual, school and school-grade level for over one million public school children. The results show that increases a one standard deviation increase in average classmate body mass index (BMI) leads to a modest but meaningful increase of 0.395 standard deviation increase in a child's own BMI. Peer-effects are highest (0.813) for children in Kindergarten and decline with age. These findings suggest that the critical time for school-grade level intervention may be in the earliest ages of childhood development.

Late 19th, early 20th century US, foreign-born body mass index values in the United States

Little work exists that compares the BMIs of 19^th century foreign-born and US-born natives. Russian, Italian, German, and French BMIs were 5.1, 3.9, 2.9, and 1.8 percent higher than that of North Americans; Asians were nearly 4.2 percent lower. African-Americans and multiracial/multiethnic individual BMIs were 4.9 and 3.8 percent greater than fairer complexioned whites, indicating there was no multiracial/multiethnic BMI advantage. Farm laborers and ranchers had BMIs that were 2.9 percent and 2.2 percent greater, respectively, than that of workers with no occupations.

Does stress influence sleep patterns, food intake, weight gain, abdominal obesity and weight loss interventions and vice versa?

Decades of research have reported only weak associations between the intakes of specific foods or drinks and weight gain and obesity. Randomized controlled dietary intervention trials have only shown very modest effects of changes in nutrient intake and diet composition on body weight in obese subjects. This review summarizes the scientific evidence on the role mental stress (either in or not in association with impaired sleep) may play in poor sleep, enhanced appetite, cravings and decreased motivation for physical activity. All these factors contribute to weight gain and obesity, possibly via decreasing the efficacy of weight loss interventions. We also review evidence for the role that lifestyle and stress management may play in achieving weight loss in stress-vulnerable individuals with overweight.

Cohort-based income gradients in obesity among U.S. adults

OBJECTIVES

No studies have focused on socioeconomic disparities in obesity within and between cohorts. Our objectives were to examine income gradients in obesity between birth-cohorts (inter-cohort variations) and within each birth-cohort (intra-cohort variations) by gender and race/ethnicity.

METHODS

Our sample includes 56,820 white and black adults from pooled, cross-sectional National Health and Nutrition Examination Surveys (1971-2012). We fit a series of logistic hierarchical Age-Period-Cohort models to control for the effects of age and period, simultaneously. Predicted probabilities of obesity by poverty-to-income ratio were estimated and graphed for 5-year cohort groups from 1901-1990. We also stratified this relationship for four gender and racial/ethnic subgroups.

RESULTS

Obesity disparities due to income were weaker for post-World War I and II generations, specifically the mid-1920s and the mid-1940s to 1950s cohorts, than for other cohorts. In contrast, we found greater income gradients in obesity among cohorts from the 1930s to mid-1940s and mid-1960s to 1970s. Moreover, obesity disparities due to income across cohorts vary markedly by gender and race/ethnicity. White women with higher income consistently exhibited a lower likelihood of obesity than those with lower income since early 1900s cohorts; whereas, black men with higher income exhibited higher risks of obesity than those with lower income in most cohorts.

CONCLUSIONS

Our findings suggest that strategies that address race and/or gender inequalities in obesity should be cognizant of significant historical factors that may be unique to cohorts. Period-based approaches that ignore life-course experiences captured in significant cohort-based experiences may limit the utility of policies and interventions.

The BMI values of the lower classes likely declined during the Great Depression

The BMI values of inmates in the McNeil Island Penitentiary in Washington State declined between the 1860s and the 1910s birth cohorts by 1.44. Furthermore, those who were imprisoned in the 1930s had significantly lower BMI values (by between 0.72 and 1.01) than those who were incarcerated at the end of the 19th century. This corresponds to a decrease in weight of some 2.25kg (4.95lbs) for a man of average height of 173.86cm (68.5inches). The diminution in nutritional status among this lower-class sample is hardly surprising, given the high level of unemployment at the time but has not been verified until now. In marked contrast, the BMI values of Citadel cadets increased by 1.5 units in the 1930s. This divergence in BMI values is most likely due to the different social status, to the different regional origins of the two samples or to both.

BODY MASS INDEX VALUES IN THE GENTRY AND PEASANTRY IN NINETEENTH AND EARLY TWENTIETH CENTURY POLAND

The aim of this study was to assess the impact of social and occupational status on the BMI of the gentry and peasantry in the Kingdom of Poland at the turn of 19th and early 20th centuries. Use was made of data on the height and weight of 304 men, including 200 peasants and 104 gentlemen, and 275 women, including 200 from the peasantry and 75 from the gentry. Gentlemen were characterized by a greater body height than peasants (169.40 cm and 166.96 cm, respectively), a greater body weight (67.09 kg and 60.99 kg, respectively) and a higher BMI (23.33 kg/m2 and 21.83 kg/m2, respectively). Landowners and intelligentsia had a greater BMI than peasants (23.12 kg/m2 and 24.20 kg/m2 vs 21.83 kg/m2, respectively). In the case of women, there were no statistically significant differences in mean height, weight and BMI by their social position, and in BMI by occupational status. Underweight occurred less frequently in the gentry and more frequently in the peasantry (0.97% and 2.04%, respectively). Overweight was five times more common in gentlemen than in peasants (26.21% and 5.10%, respectively). Differences in the BMI of gentlefolk and peasants resulted from differences in diet and lifestyle related to socioeconomic status.

From Undernutrition to Overnutrition: The Evolution of Overweight and Obesity among Young Men in Switzerland since the 19th Century

OBJECTIVE

The global obesity epidemic continues, new approaches are needed to understand the causes. We analyzed data from an evolutionary perspective, stressing developmental plasticity.

METHODS

We present diachronical height, weight, and BMI data for 702,902 Swiss male conscripts aged 18-20 years, a representative, standardized and unchanged data source.

RESULTS

From 1875 to 1879, the height distribution was slightly left-skewed; 12.1% of the conscripts were underweight, overweight and obesity were rare. The BMI-to-height relationship was positive but not linear, and very short conscripts were particularly slim. Since the 1870s, Swiss conscripts became taller, a trend that markedly slowed in the 1990s. In contrast, weight increased in two distinct steps at the end of the 1980s and again after 2002. Since 2010, BMI did not increase but stabilized at a high level.

CONCLUSIONS

The body of young men adapted differently to varying living conditions over time: First, less investment in height and weight under conditions of undernutrition and food uncertainty; second, more investment in height under more stable nutritional conditions; third, development of obesity during conditions of plateaued height growth, overnutrition, and decreasing physical activity. This example contributes to the evaluation of hypotheses on human developmental plasticity.

Reducing Societal Obesity: Establishing a Separate Exercise Model through Studies of Group Behavior

The past 50 years has brought attention to high and increasing levels of human obesity in most of the industrialized world. The medical profession has noticed, has evaluated, and has developed models for studying, preventing, and reversing obesity. The current model prescribes activity in specific quantities such as days, minutes, heart rates, and footfalls. Although decreased levels of activity have come from changes revolving around built environments and social networks, the existing medical model to lower body weights by increasing activity remains individually prescriptive. It is not working. The study of societal obesity precludes the individual and must involve group behavioral studies. Such studies necessitate acquiring separate tools and, therefore, require a significant change in the evaluation and treatment of obesity. Finding groups with common activities and lower levels of obesity would allow the development of new models of land use and encourage active lifestyles through shared interests.

Overweight trends among Polish schoolchildren before and after the transition from communism to capitalism

This study aims to reveal the secular trends in body mass index (BMI) and the prevalence of overweight and obesity among Polish schoolchildren between the years 1966-2012, during which intense socio-political changes took place. Four surveys were conducted in several districts of Poland looking at 69,746 schoolchildren aged 7-18. Significant increase in mean BMI as well as in the prevalence of overweight and obesity was observed. During this time the highest increase in both mean BMI and excess weight was observed between 1988 and 2012, i.e. after the political transformation, resulting in the improvement of living conditions. However, with respect to girls in late adolescence, between these years, the mean BMI as well as the prevalence of overweight were leveling off, while the percentage of boys with excess body fat in the same developmental category significantly increased in 2012. In the years 1966-1978 and 1978-1988 the pattern of changes in the prevalence of overweight and obesity reflected the social and economic circumstances, i.e. temporary economic improvements, or deepening political crises and food shortage. In conclusion, the weight status of schoolchildren strongly reflects socio-political changes that took place in Poland, as well as in most of the Central European countries in the last half century.

Menthol cigarette smoking and obesity in young adult daily smokers in Hawaii

This study investigates 1) the relationship between menthol cigarette smoking and obesity and 2) the association of body mass index with the nicotine metabolite ratio among menthol and non-menthol daily smokers aged 18–35 (n = 175). A brief survey on smoking and measures of height and weight, carbon monoxide, and saliva samples were collected from participants from May to December 2013 in Honolulu, Hawaii. Multiple regression was used to estimate differences in body mass index among menthol and non-menthol smokers and the association of menthol smoking with obesity. We calculated the log of the nicotine metabolite ratio to examine differences in the nicotine metabolite ratio among normal, overweight, and obese smokers. Sixty-eight percent of smokers used menthol cigarettes. Results showed that 62% of normal, 54% of overweight, and 91% of obese smokers used menthol cigarettes (p = .000). The mean body mass index was significantly higher among menthol compared with non-menthol smokers (29.4 versus 24.5, p = .000). After controlling for gender, marital status, educational attainment, employment status, and race/ethnicity, menthol smokers were more than 3 times as likely as non-menthol smokers to be obese (p = .04). The nicotine metabolite ratio was significantly lower for overweight menthol smokers compared with non-menthol smokers (.16 versus .26, p = .02) in the unadjusted model, but was not significant after adjusting for the covariates. Consistent with prior studies, our data show that menthol smokers are more likely to be obese compared with non-menthol smokers. Future studies are needed to determine how flavored tobacco products influence obesity among smokers.

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Young adult menthol smokers had a higher body mass index than non-menthol smokers.

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Nearly 91% of young adult obese daily smokers used menthol cigarettes.

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Daily menthol smokers were 3 times as likely to be obese than non-menthol smokers.

A Weighty Issue: Diminished Net Nutrition Among the U.S. Working Class in the Nineteenth Century

Much has been written about the modern obesity epidemic, and historical BMIs are low compared with their modern counterparts. However, interpreting BMI variation is difficult because BMIs increase when weight increases or when stature decreases, and the two have different implications for human health. An alternative measure for net current nutritional conditions is body weight. After controlling for height, I find that African American and white weights decreased throughout the late nineteenth and early twentieth centuries. Farmers had greater average weights than workers in other occupations. Individuals from the South had taller statures, greater BMIs, and heavier weights than workers in other U.S. regions, indicating that even though the South had higher disease rates in the nineteenth century, it had better net nutritional conditions.

An economy of scales: A selective review of obesity's economic causes, consequences, and solutions

This paper reviews the economic research on obesity, covering topics such as the measurement of, and trends in, obesity, the economic causes of obesity (e.g. the monetary price and time cost of food, food assistance programs, income, education, macroeconomic conditions, and peer effects), and the economic consequences of obesity (e.g. lower wages, a lower probability of employment, and higher medical care costs). It also examines the extent to which obesity imposes negative externalities, and economic interventions that could potentially internalize such externalities, such as food taxes, subsidies for school-based physical activity programs, and financial rewards for weight loss. It discusses other economic rationales for government intervention with respect to obesity, such as imperfect information, time inconsistent preferences, and irrational behavior. It concludes by proposing a research agenda for the field. Overall, the evidence suggests that there is no single dominant economic cause of obesity; a wide variety of factors may contribute a modest amount to the risk. There is consistent evidence regarding the economic consequences of obesity, which are lower wages and higher medical care costs that impose negative externalities through health insurance. Studies of economic approaches to preventing obesity, such as menu labeling, taxes on energy-dense foods, and financial rewards for weight loss find only modest effects on weight and thus a range of policies may be necessary to have a substantial effect on the prevalence of obesity.

Research contributions on childhood obesity from a public-private partnership

BACKGROUND

Childhood obesity remains a significant global problem with immediate and long-term individual health and societal consequences. Targets for change should include the most potent and predictive factors for obesity at all levels of the personal, social and physical environments. The Michael & Susan Dell Center for Healthy Living ('the Center') is a public-private partnership that was developed to address child health issues through research, service, and education. This overview paper introduces a special issue of seven articles on childhood obesity from the Center, and the implications of this research for obesity prevention.

METHODS AND RESULTS

A review of the literature on public-private partnerships was undertaken and key components of the partnership between the Michael & Susan Dell Foundation and the Center were compared for compatibility. The conceptual framework for Center research, based on social cognitive theory and the social-ecological model, is explained. An overview of papers in this special issue, relative to the conceptual framework, and the implications of this research for childhood obesity prevention, are provided.

CONCLUSIONS

The public-private partnership that created the Michael & Susan Dell Center for Healthy Living has been instrumental in motivating the Center’s academic faculty to focus their research on improvements in child, family and community health through etiologic, epidemiologic, methodologic and intervention research. This special issue extends this work and places particular emphasis on socioeconomic inequalities in addressing the obesity problem in the U.S. and worldwide.

The Challenges and Opportunities Associated with Reimbursement for Obesity Pharmacotherapy in the USA

Obesity has become a serious public health problem that has stimulated primordial and primary prevention efforts, and a triad of management options (lifestyle, pharmacotherapy, and surgical interventions). A growing body of evidence supports the need for a multi-pronged, clinic-based approach that leverages the synergy between pharmaceutical and lifestyle modification. Recent US policy changes-namely, the passage of the Patient Protection and Affordable Care Act coupled with recognition of obesity as a disease by the American Medical Association-suggest that financial incentives and attitudes towards obesity management are changing. This paradigm shift has implications for current and future obesity pharmacotherapy. However, barriers to pharmacotherapy utilization include patient and physician perceptions of modest efficacy, historical safety issues, regulatory obstacles, and lack of reimbursement. The shifting attitudes and challenges associated not only with a multi-payer system, but also the lack of clearly defined cross-payer reimbursement strategies, prompted a survey to determine coverage for obesity treatment. Participants indicated that federal/state mandates and growth of quality-driven healthcare initiatives will eventually drive wider pharmacotherapy reimbursement within 1-5 years. There are signs that federal/state programs are already moving towards reimbursement by improving quality measures to track obesity outcomes and reduce costs. Future research on clinical and economic outcomes of combination weight-management programs coupled with innovative approaches (e.g., eHealth) in the real-world setting that demonstrate value to patients, healthcare providers, payers, and employers will help reshape obesity management by reducing barriers and broadening reimbursement coverage for anti-obesity pharmacotherapy.

The decline in BMI among Japanese women after World War II

The body mass index (BMI) of the Japanese is significantly lower than is found in other high-income countries. Moreover, the average BMI of Japanese women is lower than that of Japanese men, and the age-specific BMI of Japanese women has decreased over time. The average BMI of Japanese women at age 25 decreased from 21.8 in 1948 to 20.4 in 2010 whereas that of men increased from 21.4 to 22.3 over the same period. We examine the long-term BMI trend in Japan by combining several historical data sources spanning eleven decades, from 1901 to 2012, to determine not only when but also how the BMI decline among women began: whether its inception was period-specific or cohort-specific. Our nonparametric regression analysis generated five findings. First, the BMI of Japanese women peaked with the 1930s birth cohort. This means that the trend is cohort-specific. Second, the BMI of men outpaced that of women in the next cohort. Third, the BMI of Japanese children, boys and girls alike, increased steadily throughout the 20th century. Fourth, the gender difference in the BMI trend is due to a gender difference in the weight trend, not the height trend. Fifth, these BMI trends are observed in urban and rural populations alike. We conclude that the BMI decline among Japanese women began with those who were in their late teens shortly after World War II.

Extending the history of child obesity in the United States: The Fels Longitudinal Study, birth years 1930-1993

OBJECTIVE

Little is known about the prevalence of child obesity in the US before the first national survey in 1963. There is disagreement about whether the obesity epidemic is entirely a recent phenomenon or a continuation of longstanding trends.

DESIGN AND METHODS

The BMIs of 1,116 children who participated in the Fels Longitudinal Study near Dayton, Ohio were analyzed. Children were born between 1930 and 1993 and measured between 3 and 18 years of age.

RESULTS

Between the birth cohorts of 1930 and 1993, the prevalence of obesity rose from 0 to 14% among boys and from 2 to 12% among girls. The prevalence of overweight rose from 10 to 28% among boys and from 9 to 21% among girls. The mean BMI Z score rose from +0.25 to +0.72 among boys and from -0.11 to +0.26 among girls. Among boys, all these increases began after birth year 1970. Among girls, obesity began to rise after birth year 1980, but overweight and BMI Z-scores were already rising as early as the 1930s and 1940s.

CONCLUSIONS

Most of the results suggest that the child obesity epidemic was recent and sudden. The recency of the epidemic offers some hope that it may be reversed.

Birth cohort effects on abdominal obesity in the United States: the Silent Generation, Baby Boomers and Generation X

BACKGROUND

Abdominal obesity predicts a wide range of adverse health outcomes. Over the past several decades, prevalence of abdominal obesity has increased markedly in industrialized countries like the United States No previous analyses, however, have evaluated whether there are birth cohort effects for abdominal obesity. Estimating cohort effects is necessary to forecast future health trends and understand the past population-level trends.

METHODS

This analysis evaluated whether there were birth cohort effects for abdominal obesity for the Silent Generation (born 1925-1945), children of the Great Depression; Baby Boomers (born 1946-1964); or Generation X (born 1965-1980). Cohort effects for prevalence of abdominal obesity were estimated using the median polish method with data collected from the National Health and Nutrition Examination Survey (NHANES) between 1988 and 2008. Respondents were aged 20-74 years.

RESULTS

After taking into account age effects and ubiquitous secular changes, the Silent Generation and Generation X had higher cohort-specific prevalence of abdominal obesity than the Baby Boomers. Effects were more pronounced in women than men.

CONCLUSIONS

This work presents a novel finding: evidence that the birth cohorts of the post-World War II Baby Boom appeared to have uniquely low cohort effects on abdominal obesity. The growing prosperity of the post-World War II US may have exposed the baby-boom generation to lower levels of psychosocial and socioeconomic stress than the previous or subsequent generations. By identifying factors associated with the Baby Boomers' low cohort-specific sensitivity to the obesogenic environment, the obesity prevention community can identify early-life factors that can protect future generations from excess weight gain.

Age, period and cohort effects on adult body mass index and overweight from 1991 to 2009 in China: the China Health and Nutrition Survey

BACKGROUND

Contributions of age-period-cohort effects to increases in BMI and overweight among Chinese adults must be resolved in order to design appropriate interventions. The objectives were to (i) describe the period effect on BMI and overweight among Chinese adults from 1991 to 2009 and assess modification of this effect by age (e.g. cohort effect) and gender, and (ii) quantify the influence of household income and community urbanicity on these effects.

METHODS

Data are from the China Health and Nutrition Survey, a prospective sample across nine provinces in China; 53,298 observations from 18,059 participants were collected over a 19-year period. A series of mixed effects models was used to explicitly assess differences in BMI within individuals over time (age effect) and population-wide differences in BMI over time (period effect), and implicitly assess differences in the experienced period effect across individuals of varying ages (cohort effect).

RESULTS

Stronger period effects on BMI and overweight were observed among males compared with females; and younger cohorts had higher BMIs compared with older cohorts. Simulations predicted that increases in income and urbanicity in the order of magnitude of that observed from 1991 to 2009 would correspond to shifts in the BMIs of average individuals of 0.07 and 0.23 kg/m(2), respectively.

CONCLUSIONS

Although period effects had a stronger influence on the BMI of males, interventions should not overlook younger female cohorts who are at increased risk compared with their older counterparts.

Birth cohort effects among US-born adults born in the 1980s: foreshadowing future trends in US obesity prevalence

BACKGROUND

Obesity prevalence stabilized in the US in the first decade of the 2000s. However, obesity prevalence may resume increasing if younger generations are more sensitive to the obesogenic environment than older generations.

METHODS

We estimated cohort effects for obesity prevalence among young adults born in the 1980s. Using data collected from the National Health and Nutrition Examination Survey between 1971 and 2008, we calculated obesity for respondents aged between 2 and 74 years. We used the median polish approach to estimate smoothed age and period trends; residual non-linear deviations from age and period trends were regressed on cohort indicator variables to estimate birth cohort effects.

RESULTS

After taking into account age effects and ubiquitous secular changes, cohorts born in the 1980s had increased propensity to obesity versus those born in the late 1960s. The cohort effects were 1.18 (95% CI: 1.01, 1.07) and 1.21 (95% CI: 1.02, 1.09) for the 1979-1983 and 1984-1988 birth cohorts, respectively. The effects were especially pronounced in Black males and females but appeared absent in White males.

CONCLUSIONS

Our results indicate a generational divergence of obesity prevalence. Even if age-specific obesity prevalence stabilizes in those born before the 1980s, age-specific prevalence may continue to rise in the 1980s cohorts, culminating in record-high obesity prevalence as this generation enters its ages of peak obesity prevalence.

Twelve year experience of laparoscopic gastric plication in morbid obesity: development of the technique and patient outcomes

BACKGROUND

Laparoscopic Gastric Plication (LGP) is a new restrictive bariatric surgery, previously introduced by the author. The aim of this study is to explain the modifications and to present the 12-year experience, regarding early and long term results, complications and cost.

METHODS

We used LGP for morbid obesity during the past 12 years. Anterior plication (10 cases), one-row bilateral plication while right gastroepiploic artery included (42 cases), and excluded from the plication (104 cases) and two-row plication (644 cases). The gastric greater curvature was plicated using 2/0 prolen from fundus at the level of diaphragm preserving the His angle to just proximal to the pylorus. The anatomic and functional volume of stomach was 50cc and 25cc respectively in two-row method. Ordered postop visits also included evaluation of weight loss, complications, change of diet and control of exercise.

RESULTS

LGP was performed in 800 cases (mean age: 27.5, range: 12 to 65 years, nine under 18). Female to male ratio was 81% to 19% and average BMI was 42.1 (35-59). The mean excess weight loss (EWL) was 70% (40% to 100%) after 24 months and 55% (28% to 100%) after 5 years following surgery. 134 cases (16.7%) did not completed long term follow-up. The average time of follow up was 5 years (1 month to 12 years). 5.5% and 31% of cases complained from weight regain respectively during 4 and 12 years after LGP. The mean time of operation was 72 (49-152) minutes and average hospitalization time was 72 hours (24 hours to 45 days). The cost of operation was 2000 $ less than gastric banding or sleeve and 2500 $ less than gastric bypass. Eight patients out of 800 cases (1%) required reoperation due to complications like: micro perforation, obstruction and vomiting following adhesion of His angle. Other complications included hepatitis pneumonia, self-limiting intra-abdominal bleeding and hypocalcaemia.

CONCLUSION

The percentage of EWL in this technique is comparable to other restrictive methods. The technique is safe with 1.6% complication (1% reoperated), and 31% regain during 12 years. The cost of operation is less than the other methods.

Bigger bodies: long-term trends and disparities in obesity and body-mass index among U.S. adults, 1960-2008

Increasing obesity rates and corresponding public health problems are well-known, and disparities across socioeconomic groups are frequently reported. However, the literature is less clear on whether the increasing trends are specific to certain socioeconomic groups and whether disparities in obesity are increasing or decreasing over time. This knowledge sheds light on the understanding of the driving forces to the ongoing worldwide increases in obesity and body-mass index and gives guidance to plausible interventions aiming at reverting weights back to healthy levels. The purpose of this study is to explore long-term time trends and socioeconomic disparities in body-mass index and obesity among U.S. adults. Individual level data from ten cycles of the National Health and Nutrition Examination Survey between 1960 and 2008 are used to estimate adjusted time trends in the probabilities of obesity and severe obesity and in measured body-mass index for three racial/ethnical groups, for three educational groups, and for four levels of income, stratified by gender. Time trends in the probabilities of obesity and severe obesity are estimated by linear probability models, and trends at the 15th, 50th and 85th percentiles of the adjusted body-mass index distribution are estimated by quantile regression. Divergent time trends for the different socioeconomic groups are estimated by interaction terms between socioeconomic status and year. The results show that, with some exceptions, increases in both obesity, severe obesity and body-mass index are similar across the different racial/ethnic, educational and income groups. We conclude that the increase in body-mass index and obesity in the United States is a true epidemic, whose signal hallmark is to have affected an entire society. Accordingly, a whole-society approach is likely to be required if the increasing trends are to be reversed.

Chronobiological Effects on Obesity

The development of obesity is the consequence of a multitude of complex interactions between both genetic and environmental factors. It has been suggested that the dramatic increase in the prevalence of obesity over the past 30 years has been the result of environmental changes that have enabled the full realization of genetic susceptibility present in the population. Among the many environmental alterations that have occurred in our recent history is the ever-increasing dyssynchrony between natural cycles of light/dark and altered patterns of sleep/wake and eating behavior associated with our "24-hour" lifestyle. An extensive research literature has established clear links between increased risk for obesity and both sleep deprivation and shift work, and our understanding of the consequences of such dyssynchrony at the molecular level is beginning to emerge. Studies linking alterations in cellular circadian clocks to metabolic dysfunction point to the increasing importance of chronobiology in obesity etiology.

Do economic constraints on food choice make people fat? A critical review of two hypotheses for the poverty-obesity paradox

In low income countries worldwide, rising standards of living have spurred an unprecedented rise in obesity. However, in numerous wealthy countries the trend frequently reverses with poorer and less educated women more likely to be overweight than their wealthier compatriots. One prominent explanation for this reverse gradient is that economic deprivation leads to food choices which paradoxically increase energy intake. If true, this would challenge current evolutionary accounts for the modern obesity epidemic and have serious implications for how policy makers tackle increasing obesity in the US and worldwide. In this article, we critically review the hypothesis that deprivation leads people to choose cheaper foods which in turn foster overconsumption of energy. Though the hypothesis is consistent with numerous cross-sectional studies, available longitudinal studies from high-, middle-, and low-income countries show the reverse-that when populations experience resource declines, they experience either declines in BMI or decelerations in BMI growth. Most notably, the recent recession in the US coincides with a clear deceleration in women's obesity across income groups. We conclude by briefly reviewing other plausible explanations for the reverse gradient among women in developing countries. Finally, we discuss how theoretical perspectives and comparative, historical approaches from human biology are useful tools for examining the current wealth of hypotheses about obesity in population health.

The medical care costs of obesity: an instrumental variables approach

This paper is the first to use the method of instrumental variables (IV) to estimate the impact of obesity on medical costs in order to address the endogeneity of weight and to reduce the bias from reporting error in weight. Models are estimated using restricted-use data from the Medical Expenditure Panel Survey for 2000-2005. The IV model, which exploits genetic variation in weight as a natural experiment, yields estimates of the impact of obesity on medical costs that are considerably higher than the estimates reported in the previous literature. For example, obesity is associated with $656 higher annual medical care costs, but the IV results indicate that obesity raises annual medical costs by $2741 (in 2005 dollars). These results imply that the previous literature has underestimated the medical costs of obesity, resulting in underestimates of the economic rationale for government intervention to reduce obesity-related externalities.

Trends in body mass index in adolescence and young adulthood in the United States: 1959-2002

PURPOSE

This study examined trends in body mass index (BMI) during the transition from adolescence to young adulthood by gender and race, using national data from the United States spanning for >40 years from 1959 and 2002. Although past research has investigated BMI trends separately in childhood/adolescence and adulthood, this study uniquely focused on the transition to adulthood (12-26 years) to identify the emergence of the obesity epidemic during this critical life-stage.

METHODS

Longitudinal and cross-sectional data were obtained from four nationally representative surveys: National Health and Nutrition Examination Survey, National Longitudinal Study of Adolescent Health, National Health Interview Survey, and National Longitudinal Surveys of Youth (NLSY79 and NLSY97). The analysis tracked age trends in BMI by time, which allowed for the examination of how BMI changed during the transition to adulthood and whether the patterns of change varied by period. Data best suited for trend analysis were identified. Age trends in BMI by gender and race were graphed and regression analysis was used to test for significant differences in the trends using the National Health and Nutrition Examination Survey and National Longitudinal Study of Adolescent Health.

RESULTS

BMI increased sharply in the adolescent ages, beginning in the 1990s and among young adults around 2000. This age pattern of BMI increase was more dramatic among females and blacks, particularly black females.

CONCLUSIONS

BMI increased during the transition to adulthood and these increases have grown larger over time. Obesity prevention efforts should focus on this high-risk transition period, particularly among minority populations.

Overweight and poor? On the relationship between income and the body mass index

Contrary to conventional wisdom, NHANES data indicate that the poor have never had a statistically significant higher prevalence of overweight status at any time in the last 35 years. Despite this empirical evidence, the view that the poor are less healthy in terms of excess accumulation of fat persists. This paper provides evidence that conventional wisdom is reflecting important differences in the relationship between income and the body mass index. The first finding is based on distribution-sensitive measures of overweight which indicates that the severity of overweight has been higher for the poor than the nonpoor throughout the last 35 years. The second finding is from a newly introduced estimator, unconditional quantile regression (UQR), which provides a measure of the income-gradient in BMI at different points on the unconditional BMI distribution. The UQR estimator indicates that the strongest relationship between income and BMI is observed at the tails of the distribution. There is a statistically significant negative income gradient in BMI at the obesity threshold and some evidence of a positive gradient at the underweight threshold. Both of these UQR estimates imply that for those at the tails of the BMI distribution, increases in income are correlated with healthier BMI values.

Progression of glycaemia and cardiovascular risk factors in patients of different age groups with new type 2 diabetes over 5 years of follow-up in a diabetes quality improvement initiative

AIMS

To examine progression of glycaemia and cardiovascular risk factors in type 2 diabetes cases participating in a quality improvement initiative.

METHODS

1108 new type 2 diabetes cases enrolled on the Otago Diabetes Register had clinical data recorded at baseline and 5 years. Means and standard deviations or percentages were calculated for variables of interest for <40, 40-59, 60-79 and 80-100 year age groups. p-Values for differences over time and among groups were calculated. Ordinal regression, with robust standard errors, was used to examine intensification of diabetes treatment.

RESULTS

For all age groups blood pressure and lipid levels approached recommended targets at 5 years (p<0.001). Glycated haemoglobin worsened, especially in the youngest age group (from 7.3±1.9% to 7.9±1.7%, p<0.001) who had the highest odds of more intense diabetes treatment at 5 years: 6.2 (95% CI 3.5-11.2) compared with 3.3 (95% CI 2.7-4.1) for 40-59-year olds, 2.8 (95% CI 2.3-3.3) for 60-79-year olds and 1.4 (95% CI 0.9-2.0) for ≥80-year olds.

CONCLUSIONS

Good management of type 2 diabetes patients, principally in primary care, can lead to improved blood pressure and lipid levels. Targets for glycaemic control and weight are less readily achieved especially among young age groups.

The trend of BMI values of US adults by deciles, birth cohorts 1882-1986 stratified by gender and ethnicity

We estimate trends in BMI values by deciles of the US adult population by birth cohorts 1882-1986 stratified by ethnicity and gender. The highest decile increased by some 18-22 BMI units in the course of the century while the lowest ones increased by merely 1-3 BMI units. For example, a typical African American woman in the 10th percentile and 64 in. (162.6 cm) tall increased in weight by just 12 pounds (5 kg) whereas in the 90th percentile her weight would have increased by 128 pounds (58 kg). Hence, the BMI distribution became increasingly right skewed as the distance between the deciles increased considerably. The rate of change of the BMI decile curves varied greatly over time and across gender and ethnicity. The BMI deciles of white men and women experienced upswings after the two world wars and downswings during the Great Depression and also decelerated after 1970. However, among African Americans the pattern is different during the first half of the century with men's rate of increase in BMI values decreasing substantially and that of females remaining constant at a relatively high level until the Second World War. After the war, though, the rate of change of BMI values of blacks came to resemble that of whites with an accelerating phase followed by a slowdown around the 1970s.