The "fit but fat" concept revisited: population-based estimates using NHANES

Independent and joint associations of cardiorespiratory fitness and BMI with dementia risk: the Cooper Center Longitudinal Study

OBJECTIVE

This study aimed to examine the association of midlife fitness and body mass index (BMI) with incident dementia later in life.

DESIGN AND PARTICIPANTS

A cohort study of 6428 individuals (mean age 50.9±7.6 years) from the Cooper Center Longitudinal Study.

MEASURES

Cardiorespiratory fitness and BMI were assessed twice (1970-1999) during visits to the Cooper Clinic, a preventive medicine clinic in Dallas, Texas. These measures were examined as continuous and categorical variables. As continuous variables, fitness and BMI were examined at baseline (averaged of two examinations) and as absolute change between exams (mean time 2.1±1.8 years). Variables were categorised: unfit versus fit and normal versus overweight/obese. Medicare claims data were used to obtain all-cause dementia incidence (1999-2009). Mean follow-up between midlife examinations and Medicare surveillance was 15.7 ((SD=6.2) years. Multivariable models were used to assess the associations between fitness, BMI and dementia.

RESULTS

During 40 773 person years of Medicare surveillance, 632 cases of dementia were identified. After controlling for BMI and covariates, each 1-metabolic equivalent increment in fitness was associated with 5% lower (HR 0.95; 95% CI 0.90 to 0.99) dementia risk. In comparison, after controlling for fitness and covariates, each 1 kg/m2 increment in BMI was associated with a 3.0% (HR 1.03; 95% CI 1.00 to 1.07) higher risk for dementia, yet without significance (p=0.051). Similar findings were observed when the exposures were categorised. Changes in fitness and BMI between examinations were not related to dementia. Jointly, participants who were unfit and overweight/obese had the highest (HR 2.28 95% CI 1.57 to 3.32) dementia risk compared with their fit and normal weight counterparts.

CONCLUSION

Lower midlife fitness is a risk marker for dementia irrespective of weight status. Being unfit coupled with overweight/obese status might increase one's risk for dementia even further.

"Anti-obesity medications" or "medications to treat obesity" instead of "weight loss drugs" - why language matters - an official statement of the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

Obesity is largely undertreated, in part because of the stigma surrounding the disease and its treatment. The use of the term "weight loss drugs" to refer to medications for the treatment of obesity may contribute to this stigma, leading to the idea that anyone who wants to lose weight could use them and that short-term use, only in the active weight loss phase would be enough. On the contrary, the use of terms such as "medications to treat obesity" or "anti-obesity medications" conveys the idea that the treatment is directed at the disease rather than the symptom. This joint statement by the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO) and the Brazilian Society of Endocrinology and Metabolism (SBEM) intends to alert the press, healthcare professionals and scientific community about the importance of the appropriate use of language, with the aim of improving obesity care.

Doubled-Up Households, Self-Management Behaviors, Diabetes Preventive Care Services, and Hospital Use in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) 2015-2020

OBJECTIVE

We investigated associations of living in a doubled-up household (i.e., adults living with adult children, other related adults, or other unrelated adults) with diabetes self-management behaviors, occurrence of diabetes preventive care services, and hospital use by Hispanic/Latino adults with diabetes.

RESEARCH DESIGN AND METHODS

We analyzed data from the second clinical visit (2014-2017) through subsequent annual follow-up interviews completed through January 2020 of all participants with diabetes in the Hispanic Community Health Study/Study of Latinos. Multivariable regression was used to test associations between doubled-up status with diabetes self-management behaviors (i.e., checking blood glucose level, checking feet for sores), diabetes preventive care services done by a doctor (i.e., dilated-eye examination, feet checked, hemoglobin A1c measured, urine analysis for kidney function), and hospital use (i.e., emergency department [ED] visits and hospitalizations).

RESULTS

Hispanic/Latino adults living doubled up were less likely to have their urine checked by a doctor for kidney disease compared with adults not in doubled-up households. Doubled-up status was not associated with diabetes self-management behaviors. Adults living doubled up in a household with other related adults had a 33% increased risk of ED visits compared with adults living doubled up in a household with adult children.

CONCLUSIONS

Health care settings where Hispanic/Latino adults with diabetes receive trusted care should add housing characteristics such as doubled-up status to social-needs screening to identify residents in need of connecting with housing or social services and more targeted diabetes management services.

Commentary—fat but fit…and cold? Potential evolutionary and environmental drivers of metabolically healthy obesity

As global obesity rates continue to rise, it is important to understand the origin, role and range of human variation of body mass index (BMI) in assessing health and healthcare. A growing body of evidence suggests that BMI is a poor indicator of health across populations, and that there may be a metabolically healthy obese phenotype. Here, we review the reasons why BMI is an inadequate tool for assessing cardiometabolic health. We then suggest that cold climate adaptations may also render BMI an uninformative metric. Underlying evolutionary and environmental drivers may allow for heat conserving larger body sizes without necessarily increasing metabolic health risks. However, there may also be a potential mismatch between modern obesogenic environments and adaptations to cold climates, highlighting the need to further investigate the potential for metabolically healthy obese phenotypes among circumpolar and other populations as well as the broader meaning for metabolic health.

Obesity treatment: Weight loss versus increasing fitness and physical activity for reducing health risks

We propose a weight-neutral strategy for obesity treatment on the following grounds: (1) the mortality risk associated with obesity is largely attenuated or eliminated by moderate-to-high levels of cardiorespiratory fitness (CRF) or physical activity (PA), (2) most cardiometabolic risk markers associated with obesity can be improved with exercise training independent of weight loss and by a magnitude similar to that observed with weight-loss programs, (3) weight loss, even if intentional, is not consistently associated with lower mortality risk, (4) increases in CRF or PA are consistently associated with greater reductions in mortality risk than is intentional weight loss, and (5) weight cycling is associated with numerous adverse health outcomes including increased mortality. Adherence to PA may improve if health care professionals consider PA and CRF as essential vital signs and consistently emphasize to their patients the myriad benefits of PA and CRF in the absence of weight loss.

Plasma Interleukin-10 and Cholesterol Levels May Inform about Interdependences between Fitness and Fatness in Healthy Individuals

Relationships between demographic, anthropometric, inflammatory, lipid and glucose tolerance markers in connection with the fat but fit paradigm were investigated by supervised and unsupervised learning. Data from 81 apparently healthy participants (87% females) were used to generate four classes of fatness and fitness. Principal Component Analysis (PCA) revealed that the principal component was preponderantly composed of glucose tolerance parameters. IL-10 and high-density lipoprotein, low-density lipoprotein (LDL), and total cholesterol, along with body mass index (BMI), were the most important features according to Random Forest based recursive feature elimination. Decision Tree classification showed that these play a key role into assigning each individual in one of the four classes, with 70% accuracy, and acceptable classification agreement, κ = 0.54. However, the best classifier with 88% accuracy and κ = 0.79 was the Naïve Bayes. LDL and BMI partially mediated the relationship between fitness and fatness. Although unsupervised learning showed that the glucose tolerance cluster explains the highest quote of the variance, supervised learning revealed that the importance of IL-10, cholesterol levels and BMI was greater than the glucose tolerance PCA cluster. These results suggest that fitness and fatness may be interconnected by anti-inflammatory responses and cholesterol levels. Randomized controlled trials are needed to confirm these preliminary outcomes.

The transcontinental variability of nonalcoholic fatty liver disease

AIM

To compare the phenotype of lean versus overweight (OW) and obese (OB) subjects with non-alcoholic fatty liver disease (NAFLD) across multiple continents.

METHODS

A retrospective study of histologically defined subjects from a single center each in France (Fr), Brazil (Br), India (In) and United States (US) was performed.

RESULTS

A total of 70 lean [body mass index (BMI) < 25 kg/m²] subjects (Fr:Br:In:US: 16:19:22:13) with NAFLD were compared to 136 OW (BMI > 25 kg/m², BMI < 29 kg/m²) (n = 28:33:52:23) and 224 OB subjects (BMI > 29 kg/m²) (n = 81:11:22:103). Lean French subjects had the lowest incidence of type 2 diabetes while those from Brazil (P < 0.01) had the highest. Lean subjects had similar low-density lipoprotein-cholesterol, but higher high-density lipoprotein-cholesterol compared to obese subjects in all regions. In both lean and obese subjects, there were both insulin-sensitive and insulin-resistant subjects. Lean French subjects were most insulin-sensitive while those from Brazil were mostly insulin-resistant. For each weight category, subjects from India were more insulin-sensitive than those from other regions. Disease activity increased from lean to overweight to obese in France but was similar across weight categories in other regions.

CONCLUSION

The phenotype of NAFLD in lean subjects varies by region. Some obese subjects with NAFLD are insulin-sensitive. We hypothesize that genetics and region-specific disease modifiers account for these differences.

Weight Loss Intervention Impact on the Physical Fitness Test Scores of Air Force Service Members

INTRODUCTION

Overweight and obesity are a major public health concern in the United States, including among active duty military personnel. Approximately 51% of active duty personnel are classified as overweight and 15% are classified as obese. This may impact military readiness. The current study aimed to determine if a weight loss intervention impacted fitness test scores among Air Force personnel.

MATERIALS AND METHODS

From 2014 to 2016, 204 Air Force members with overweight/obesity were randomized into either a Self-paced or counselor-initiated arm in a weight loss program. Study procedures were approved by the Institutional Review Board of the 59th Medical Wing in San Antonio and were acknowledged by the Institutional Review Board at the University of Tennessee Health Science Center. Fitness test scores from before, during, and after the intervention were used to determine if the intervention resulted in improvements in overall fitness test ratings and scores on individual components of the test.

RESULTS

Participants who lost at least 5% of their weight had better fitness ratings during the intervention compared to individuals who did not lose 5%. However, in the overall sample, fitness ratings worsened from preintervention to during the intervention, and from during to postintervention. Participants with overweight had better aerobic scores pre- and postintervention as well as better abdominal circumference scores and better fitness test ratings preintervention, during the intervention and postintervention compared to participants with obesity.

CONCLUSIONS

Behavioral weight management interventions that achieve 5% weight loss may help improve military fitness test ratings.

Physical Fitness, Body Composition, and Adherence to the Mediterranean Diet in Young Football Players: Influence of the 20 mSRT Score and Maturational Stage

This study aimed to analyze the differences in physical fitness variables, body composition, and adherence to the Mediterranean diet according to the cardiorespiratory fitness and the maturational stage in young football players. A total of 194 male football players (aged 8–16) from three football sport schools participated in this study. Data on cardiorespiratory fitness (the 20-m shuttle run test), anthropometric measurements, handgrip strength, respiratory capacity (forced spirometry), and adherence to the Mediterranean diet (KIDMED questionnaire) were collected. Players were divided into two groups depending on their maturational stage (prepubertal n = 127 and pubertal n = 67). The results show a direct relationship between low levels of cardiorespiratory fitness and body mass index, as well as body fat and leg fat. Similarly, players with lower cardiorespiratory fitness presented higher values of handgrip strength in the prepubertal state. On the other hand, improvements in respiratory values were observed in the pubertal state with the rest of the parameters when the cardiorespiratory fitness was increased. Therefore, the promotion of recreational football that encourage and develop cardiorespiratory fitness is a key factor and can be used as an effective sport activity to promote physical fitness and healthy habits in children and adolescents as well as within the population that is already physically active.

Comprehensive physical fitness and high blood pressure in children and adolescents: A national cross-sectional survey in China

OBJECTIVES

To assess the association between comprehensive physical fitness and high blood pressure (HBP) among Chinese children and adolescents.

DESIGN

National cross-sectional surveys.

METHODS

214,301 school students' data aged 7-18years was extracted in 2014. Six components of physical fitness (forced vital capacity, standing long jump, sit-and-reach, body muscle strength, 50m dash and endurance running) were measured, standardized and aggregated as a summary physical fitness indicator (PFI). HBP, systolic HBP (SHBP) and diastolic HBP (DHBP) were defined according to sex-, age- and height-specific references in China.

RESULTS

The prevalence of HBP, SHBP and DHBP was 8.6%, 4.7% and 5.7%, respectively, and PFI was -0.9 in Chinese children and adolescents. A significant negative association between the PFI and HBP was observed with adjusted prevalence of HBP (10.8% (95% CI: 10.4-11.2) to 7.6% (95% CI: 7.3-8.0), P_trend<0.001), SHBP (5.7% (95% CI: 5.4-6.1) to 4.4% (95% CI: 4.1-4.6), P_trend<0.001), and DHBP (7.6% (95% CI: 7.2-7.9) to 4.6% (95% CI: 4.3-4.9), P_trend<0.001) and their ORs (HBP: 0.87(95% CI: 0.82-0.93) to 0.68(95% CI: 0.64-0.73), P_trend<0.001; SHBP: 0.86(95% CI: 0.79-0.94) to 0.75(95% CI:0.69-0.82), P_trend<0.001; DHBP: 0.85(95% CI: 0.79-0.92) to 0.59(95% CI: 0.54-0.64), P_trend<0.001) declined with the increase in PFI. Stratified nutritional status exhibited a similar negative association between PFI and HBP, SHBP and DHBP in children with normal weight, overnutrition, and undernutrition. Stand long jump, body muscle strength, 50m dash, and endurance running, had a negative association with HBP, SHBP and DHBP, but forced vital capacity had a positive such association. Sit-and-reach and HBP are not significantly associated.

CONCLUSIONS

Physical fitness was negatively correlated to the increased HBP in children and adolescents. Comprehensive policies and measures to enhance children and adolescents' physical fitness are urgently needed through the promotion of physical activity, healthy dietary patterns, and strategies of educational guidelines to reduce schoolwork, which will in turn reduce the cardiovascular burdens in the future.

Análisis de la condición física según sexo, edad, índice de masa corporal y nivel de actividad física en estudiantes de primaria en España

Introducción. La evidencia científica sugiere que la calidad de vida de los escolares se relaciona de forma directa con el estado de su condición física (CF).Objetivo. Analizar la CF según edad, sexo, índice de masa corporal (IMC) y nivel de actividad física en estudiantes de primaria.Materiales y métodos. Se realizó un estudio descriptivo transversal con 103 escolares entre 8 y 12 años de España. La CF se midió mediante la batería ALPHA-Fitness y la actividad física, con el cuestionario Physician-based Assessment and Counseling for Exercise. Los participantes se categorizaron según su nivel de actividad física (no activos versus activos) y su IMC (normo-peso versus sobrepeso-obesidad). Para el análisis se aplicó estadística paramétrica.Resultados. Los varones tuvieron un mejor nivel de CF, pero en ambos sexos se observó un leve incremento de esta a medida que aumentaba la edad. Los escolares con normopeso o activos físicamente tuvieron una mejor capacidad aeróbica y una composición corporal más saludable.Conclusión. Mantener niveles óptimos de CF a lo largo de la vida requiere de la adopción de un estilo de vida saludable desde la infancia, por tanto, es necesario promover la práctica autónoma de actividad física en los escolares.

Mediterranean diet, weight status and physical activity in schoolchildren of the Region of Murcia

INTRODUCTION

Childhood and adolescence are key stages to promote a healthy lifestyle.

OBJECTIVE

To analyze the relationship between weight status, physical activity and the Mediterranean diet in schoolchildren in the Region of Murcia.

METHODS

Cross-sectional descriptive study with 520 schoolchildren aged 8-17 years. The weight status was calculated through the body mass index. The Mediterranean diet was found through the KIDMED questionnaire and physical activity was estimated using the IPAQ-C and IPAQ-A questionnaires.

RESULTS

The Mediterranean diet is not significantly associated with sex (P<.537) or weight status (P<.417) but it maintains a relationship of dependence with age (P<.010) and the level of physical activity (P<.000). Schoolchildren in normal weight and assets have a greater follow-up to the Mediterranean diet than their overweight and sedentary peers (P<.000).

CONCLUSION

The Fat but fit phenomenon applied to the Mediterranean diet is confirmed.

Does leisure-time physical activity attenuate or eliminate the positive association between obesity and high blood pressure?

We examine the joint association of weight status and leisure-time physical activity on high blood pressure in a nationally representative sample of adults and older adults in Brazil. This was a national cross-sectional survey conducted in Brazil in 2013 (Brazilian Health Survey). The sample consisted of 59 402 participants (56% women, aged 18 to 100 years). Outcome was objectively assessed blood pressure. Body mass index (BMI) was objectively measured, while self-reported information on leisure-time physical activity, TV viewing, chronological age, race, educational status, tobacco smoking, sodium consumption, and hypertension medication was obtained using questionnaires. Logistic regression analysis with adjusted odds ratio was conducted to test the joint association of BMI and leisure-time physical activity categories on high blood pressure. Overall, compared to normal weight (NW) and physically active group, the NW/inactive (OR = 1.28; 1.04 to 1.58), overweight/active (OR = 1.38; 1.08 to 1.78), overweight/inactive (OR = 1.89; 1.53 to 2.33), obese/active (OR = 2.19; 1.59 to 3.01) and obese/inactive (OR = 2.54; 2.05 to 3.15) groups were 28% to 254% more likely to have high blood pressure. The attenuation and high blood pressure was greater for women and adults than for men and older adults. Thus, leisure-time physical inactivity and being overweight and obesity were associated with high blood pressure in Brazilian population. Engaging in sufficient level of physical activity during leisure could attenuate, but not eliminate, the negative influence of obesity on high blood pressure in Brazilian adults and older adults.

An assessment of the relationship of physical activity, obesity, and chronic diseases/conditions between active/obese and sedentary/ normal weight American women in a national sample

OBJECTIVE

Obesity and physical inactivity are associated with increased rates of chronic diseases and conditions. However, the 'fit but fat' theory posits that cardiopulmonary fitness (or physical activity) can mitigate risks to health associated with obesity. The purpose of this study was to compare chronic diseases and conditions of highly active/obese women with inactive/normal weight women.

STUDY DESIGN

This was a cross-sectional study of the 2015 Behavioral Risk Factor Surveillance System data.

METHODS

Weighted descriptive statistics were performed to describe the demographic characteristics of the two groups. We calculated odds ratios and adjusted odds ratios for chronic diseases and conditions comparing highly active/obese women with inactive/normal weight women.

RESULTS

Highly active/obese women were more likely to report risk factors (hypertension, high cholesterol, and diabetes) for coronary heart disease (CHD) and cardiovascular disease (CVD) than inactive/normal weight women; however, they did not have increased rates of CVD, CHD, or heart attack and had decreased risk for stroke. Highly active/obese women had increased risk for asthma, arthritis, and depression, but not for cancer, kidney disease, or chronic obstructive pulmonary disease.

CONCLUSIONS

Highly active/obese women appear to be staving off the actual development of CHD and CVD; however, further research is needed to understand the long-term health benefits of physical activity among obese women.

From Sea to Shining Sea and the Great Plains to Patagonia: A Review on Current Knowledge of Diabetes Mellitus in Hispanics/Latinos in the US and Latin America

The past two decades have witnessed many advances in the prevention, treatment, and control of diabetes mellitus (DM) and its complications. Increased screening has led to a greater recognition of type 2 diabetes mellitus (type 2 DM) and prediabetes; however, Hispanics/Latinos, the largest minority group in the US, have not fully benefited from these advances. The Hispanic/Latino population is highly diverse in ancestries, birth places, cultures, languages, and socioeconomic backgrounds, and it populates most of the Western Hemisphere. In the US, the prevalence of DM varies among Hispanic/Latino heritage groups, being higher among Mexicans, Puerto Ricans, and Dominicans, and lower among South Americans. The risk and prevalence of diabetes among Hispanics/Latinos are significantly higher than in non-Hispanic Whites, and nearly 40% of Hispanics/Latinos with diabetes have not been formally diagnosed. Despite these striking facts, the representation of Hispanics/Latinos in pharmacological and non-pharmacological clinical trials has been suboptimal, while the prevalence of diabetes in these populations continues to rise. This review will focus on the epidemiology, etiology and prevention of type 2 DM in populations of Latin American origin. We will set the stage by defining the terms Hispanic, Latino, and Latin American, explaining the challenges identifying Hispanics/Latinos in the scientific literature and databases, describing the epidemiology of diabetes-including type 2 DM and gestational diabetes mellitus (GDM)-and cardiovascular risk factors in Hispanics/Latinos in the US and Latin America, and discussing trends, and commonalities and differences across studies and populations, including methodology to ascertain diabetes. We will discuss studies on mechanisms of disease, and research on prevention of type 2 DM in Hispanics/Latinos, including women with GDM, youth and adults; and finalize with a discussion on lessons learned and opportunities to enhance research, and, consequently, clinical care oriented toward preventing type 2 DM in Hispanics/Latinos in the US and Latin America.

A Content Analysis of Physical Activity in TV Shows Popular Among Adolescents

PURPOSE

Previous research has demonstrated that television has the potential to influence youth behaviors, but little evidence exists on how television depicts physical activity (PA), an important public health priority for youth. This mixed-methods study investigated depictions of television characters' participation in PA in the top 25 favorite shows ranked by a diverse sample of 2,793 adolescents.

METHOD

Randomly selected episodes from each show were content-analyzed for PA incidents, reasons, and context and in relation to the gender and weight status of participating characters.

RESULTS

A total of 374 incidents of PA were coded across 75 episodes, with an average of 5.0 incidents per episode. Although male and female characters were equally likely to engage in at least 1 incident of PA, male characters were involved in a statistically significantly larger proportion of PA incidents than were female characters, and they were more likely to engage in PA for competitive sport. There was no statistically significant difference in engagement in PA or the proportion of PA incidents for characters coded as overweight compared with nonoverweight characters.

CONCLUSIONS

Although female characters tended to be underrepresented in PA, this study reveals positive messages for how gender and weight are portrayed in relation to PA on TV.

Improving heart health among Black/African American women using civic engagement: a pilot study

BACKGROUND

Despite increased risk for cardiovascular disease (CVD) and related conditions, evaluations of health interventions indicate that Black/African American women are less likely to benefit than their white counterparts and are not as likely to engage in behaviors that reduce CVD risk. The purpose of this study was to test the feasibility and effectiveness of civic engagement as an intervention strategy to address heart health in Black/African American women.

METHODS

Using a quasi-experimental pre-post study design, civic engagement was tested by convening a convenience sample of self-identified Black/African American women, ages 30-70 years, English-speaking, and BMI ≥25.0 (n = 28) into "Change Clubs" in four churches. Feasibility was examined through adherence, satisfaction, retention, and ability of Change Clubs to meet at least 50% of self-identified action steps for community change. Effectiveness data included: dietary intake, measures of physical activity, cardiorespiratory fitness, blood pressure, and anthropometrics. Psychosocial factors hypothesized to serve as the mechanisms by which civic engagement enacts behavior change were also assessed.

RESULTS

At baseline, the study sample (n = 28) had a mean age of 50.5 y; 53.6% had an associate degree or higher; 60.7% had an income of $35,000 or higher; and 57.4% were employed full time. At the conclusion of the study, all participants were satisfied with the progress of their Change Club and with the overall experience and Change Clubs met their self-identified action steps for community change. The intervention had a significant effect on finish time on the cardiorespiratory fitness test (p < 0.001) and systolic blood pressure (p < 0.001).

CONCLUSIONS

Study results suggest feasibility and evidence of preliminary effectiveness of using a civic engagement approach to address behavior change in a way that is appealing and acceptable to Black/African American women.

TRIAL REGISTRATION

NCT02173366.

Is the calorie concept a real solution to the obesity epidemic?

BACKGROUND

The obesity epidemic has been growing steadily across the whole world, and so far not a single country has been able to reverse it. The cause of obesity is stated by the World Health Organization as an energy imbalance between calories consumed and calories expended. However, growing evidence suggests that the calorie imbalance concept may not be sufficient to manage and reverse the obesity epidemic.

OBJECTIVE

To discuss the use of the calorie imbalance concept and its elements as a tool for weight management as well as its possible negative consequences and implications for public health, with the aim to point toward the need of an updated concept for causes of obesity. This update should guide public health interventions more efficiently to limit obesity by preventing weight gain or promoting weight loss.

METHODS

This is a literature reviews based on a semi-structured approach to determine the material to be examined.

RESULTS

After revisiting general facts about fat generation and accumulation, we propose an updated concept for the causes of obesity including diet composition and hormonal regulation of fat metabolism.

CONCLUSIONS

We discuss how this updated concept could benefit the overall efficiency of strategies against obesity, and hypothesize how potential resistance to adopting this new view could be lowered.

Health Outcomes in Relation to Physical Activity Status, Overweight/Obesity, and History of Overweight/Obesity: A Review of the WATCH Paradigm

Previous research has shown that physical activity may mitigate the association between overweight/obesity and a number of negative health outcomes; however, less is known on how the duration of overweight/obesity alters this association. Therefore, the purpose of this leading article was to synthesize recent studies from our research group examining how physical activity, overweight/obesity classification, and importantly, overweight/obesity duration impact the association with a variety of different health outcomes. Five studies were analyzed, each of which used data from the National Health and Nutrition Examination Survey to analyze six mutually exclusive groups and their respective association with cardiovascular disease risk, all-cause mortality, multi-morbidity, health-related quality of life, and mild depressive symptoms. These studies detailed that physical inactivity, overweight/obesity classification, and overweight/obesity duration were each independently associated with cardiovascular disease risk and multi-morbidity. Additionally, physical activity reduced the risk of all-cause mortality across all weight classifications/durations, and also reduced the association with depressive symptoms and poor health-related quality of life among those overweight/obese for longer durations. These results illustrate that, while physical activity may reduce the association with negative health outcomes, overweight/obesity appears to increase this association independent of physical activity level, with this further exacerbated by the duration of overweight/obesity. Therefore, the emerging studies examining the importance of physical activity among overweight/obese individuals should also consider the duration of overweight/obesity as this will likely alter the associations present.

Epidemiology of Obesity and Diabetes and Their Cardiovascular Complications

Obesity and diabetes mellitus have reached epidemic proportions in the past few years. During 2011 to 2012, more than one-third of the US population was obese. Although recent trend data indicate that the epidemic has leveled off, prevalence of abdominal obesity continues to rise, especially among adults. As seen for obesity, the past few decades have seen a doubling of the diabetes mellitus incidence with an increasing number of type 2 diabetes mellitus cases being diagnosed in children. Significant racial and ethnic disparities exist in the prevalence and trends of obesity and diabetes mellitus. In general, in both adults and children, non-Hispanic blacks and Mexican Americans seem to be at a high risk than their non-Hispanic white counterparts. Secular changes in agricultural policies, diet, food environment, physical activity, and sleep have all contributed to the upward trends in the diabesity epidemic. Despite marginal improvements in physical activity and the US diet, the food environment has changed drastically to an obesogenic one with increased portion sizes and limited access to healthy food choices especially for disadvantaged populations. Interventions that improve the food environment are critical as both obesity and diabetes mellitus raise the risk of cardiovascular disease by ≈2-fold. Among those with type 2 diabetes mellitus, significant sex differences occur in the risk of cardiovascular disease such that diabetes mellitus completely eliminates or attenuates the advantages of being female. Given the substantial burden of obesity and diabetes mellitus, future research efforts should adopt a translational approach to find sustainable and holistic solutions in preventing these costly diseases.

Obesity and Cardiovascular Disease

The prevalence of obesity has increased worldwide over the past few decades. In 2013, the prevalence of obesity exceeded the 50% of the adult population in some countries from Oceania, North Africa, and Middle East. Lower but still alarmingly high prevalence was observed in North America (≈30%) and in Western Europe (≈20%). These figures are of serious concern because of the strong link between obesity and disease. In the present review, we summarize the current evidence on the relationship of obesity with cardiovascular disease (CVD), discussing how both the degree and the duration of obesity affect CVD. Although in the general population, obesity and, especially, severe obesity are consistently and strongly related with higher risk of CVD incidence and mortality, the one-size-fits-all approach should not be used with obesity. There are relevant factors largely affecting the CVD prognosis of obese individuals. In this context, we thoroughly discuss important concepts such as the fat-but-fit paradigm, the metabolically healthy but obese (MHO) phenotype and the obesity paradox in patients with CVD. About the MHO phenotype and its CVD prognosis, available data have provided mixed findings, what could be partially because of the adjustment or not for key confounders such as cardiorespiratory fitness, and to the lack of consensus on the MHO definition. In the present review, we propose a scientifically based harmonized definition of MHO, which will hopefully contribute to more comparable data in the future and a better understanding on the MHO subgroup and its CVD prognosis.

Cardiometabolic and Fitness Improvements in Obese Girls Who Either Gained or Lost Weight during Treatment

OBJECTIVE

To evaluate the quality of weight change (change in fat mass vs fat-free mass [FFM]), changes in cardiorespiratory fitness (CRF), and frequencies of metabolic risk factors in adolescent females with obesity who either lost or gained weight following lifestyle treatment.

STUDY DESIGN

Fifty-eight girls (mean age = 13.0 ± 1.6 years; 77% black; mean body mass index = 36.5 ± 4.5 kg/m(2)) completed a 6-month lifestyle intervention combining dietary and behavioral counseling with aerobic and resistance exercise training. We examined baseline to 6-month differences in weight (kg), body composition, CRF, and frequencies of metabolic risk factors between weight loss and weight gain groups.

RESULTS

In the weight loss group, body weight (-4.50 ± 3.53 kg, P < .001), fat mass (-4.50 ± 2.20 kg, P < .001), and body fat percentage (-2.97% ± 1.45%, P < .001) decreased, and FFM was unchanged at 6 months. In the weight gain group, body weight (4.50 ± 2.20 kg, P < .001), fat mass (1.52 ± 3.16 kg, P < .024), and FFM (2.99 ± 2.45 kg, P < .001) increased, and body fat percentage was unchanged. Both groups improved CRF (P < .05). Frequencies of metabolic risk factors were reduced across all participants after the 6-month treatment.

CONCLUSIONS

Participation in a weight management program might elicit health improvements in obese adolescent females who increase weight and fat mass, provided that FFM gains are sufficient to negate increases in body fat percentage.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00167830.

Diet, exercise or diet with exercise: comparing the effectiveness of treatment options for weight-loss and changes in fitness for adults (18-65 years old) who are overfat, or obese; systematic review and meta-analysis

There are number of means of methods to alter body composition, and metabolic issues, available for the adult who is overfat. The following is a systematic review and meta-analysis focused on comparing changes from treatment program for adults who are overfat based on analysis of aggregated effect size (ES) of inducing changes. So as to determine the relative effectiveness of such protocols and intervention plans of choice. This tiered meta-analysis of 66-population based studies, and 162-studywise groups, a clear pattern of ES being established across and within treatments. First, hypocaloric balance is necessary for changing body composition, but the effectiveness for establishing imbalance does not equate with the effectiveness for body compositional changes, or any biomarkers associated with metabolic issues. With analysis showing that there is a necessity to include exercise in combination with diet effectively elicit changes in body composition and biomarkers of metabolic issues. More importantly, the combination, resistance training (RT) was more effective than endurance training (ET) or combination of RT and ET, particularly when progressive training volume of 2-to-3 sets for 6-to-10 reps at an intensity of ≥75% 1RM, utilizing whole body and free-weight exercises, at altering body compositional measures (ES of 0.47, 0.30, and 0.40 for loss of BM, FM, and retention of FFM respectively) and reducing total cholesterol (ES = 0.85), triglycerides (ES = 0.86) and low-density lipoproteins (ES = 0.60). Additionally RT was more effective at reducing fasting insulin levels (ES = 3.5) than ET or ET and RT. Even though generally lower ES than RT, the inclusion of ET was more effective when performed at high intensity (e.g. ≥70% VO2max or HRmax for 30-minutes 3-4x's/wk), or in an interval training style than when utilizing the relatively common prescribed method of low-to-moderate (e.g., 50-70% VO2max or HRmax for at least equal time) steady state method, ES of 0.35, 0.39, and 0.13 for BM, FM, and FFM respectively. Thus indicating that focus of treatment should be on producing a large metabolic stress (as induced by RT or high levels of ET) rather than an energetic imbalance for adults who are overfat.

Measures of cardiorespiratory fitness in relation to measures of body size and composition among children

BACKGROUND

In the exercise testing measures of cardiorespiratory fitness need to be scaled by body size or composition to enable comparison between individuals. Traditionally used weight-proportional measures are potentially confounded by body adiposity that hampers their interpretation and applicability in the clinical assessment of cardiorespiratory fitness.

OBJECTIVE

We aimed to find the most appropriate measure of body size or composition for scaling of measures of cardiorespiratory fitness among children.

METHODS

We assessed body weight and height, maximal workload (W MAX ) and maximal oxygen uptake (VO2 MAX ) using cycle ergometer exercise test with respiratory gas analysis and body lean mass (LM) and fat mass (FM) by dual-energy X-ray absorptiometry and by bioimpedance analysis among 38 children. The data were analysed using Pearson's coefficients for correlation and stepwise linear regression models.

RESULTS

Lean mass (r > 0.54) and height (r > 0.51) had stronger positive correlations with absolute W MAX and VO2 MAX than weight (r > 0.30) in girls and boys. None of the measures of body size or composition correlated with LM-proportional W MAX or VO2 MAX in girls or boys. Only LM correlated positively with height-proportional W MAX (r = 0.65) and VO2 MAX (r = 0.71) in boys. FM correlated negatively with weight-proportional W MAX (r < -0.58) and VO2 MAX (r < -0.64) in girls and boys. FM was even stronger determinant of weight-proportional W MAX (β = -0.68) and VO2 MAX (β = -0.61) than exercise performance in multivariate linear regression models.

CONCLUSIONS

While assessing cardiorespiratory fitness, LM is the most appropriate measure of body size or composition for scaling of W MAX and VO2 MAX, because scaling by body weight introduces confounding by body adiposity.

Independent and combined effect of diet and exercise in adults with prediabetes

Prediabetes is defined as impaired fasting glucose and/or impaired glucose tolerance. Impaired fasting glucose is usually defined as fasting blood glucose between 5.6 mmol/L and 6.9 mmol/L (100.8-124.2 mg/dL), and impaired glucose tolerance is the 2-hour oral glucose tolerance test of 7.8-11.0 mmol/L (140.4-198.0 mg/dL). Most individuals with prediabetes are overweight or obese and are at greater risk of type 2 diabetes (T2D). The first line of treatment for individuals with prediabetes is lifestyle modification, including diet and exercise. The aim of this review, through the revision of primarily randomized control trials, is to discuss the independent and combined effect of diet and exercise on the incidence of T2D, glycemic control, and weight loss in adults with prediabetes. Based on the available literature, lifestyle modification combining both diet and exercise is effective at reducing the incidence of T2D and improving glycemic control, even without a significant reduction in body weight. Thus, it is unclear whether weight loss, through lifestyle modification, is a cornerstone for improving glycemic control in individuals with prediabetes. The independent effect of diet or exercise alone on the improvement in glycemic control and/or reduction in body weight in individuals with prediabetes still requires more studies to draw a clear conclusion, considering the quality and quantity of available studies. As of now, the best diet and/or exercise program to improve glycemic control and body weight in adults with prediabetes is unknown.

Associations of cardiorespiratory fitness and fatness with metabolic syndrome in rural women with prehypertension

BACKGROUND

This study investigated the associations of fitness and fatness with metabolic syndrome in rural women, part of a recognized US health disparities group.

METHODS

Fitness, percentage body fat, BMI, and metabolic syndrome criteria were assessed at baseline in 289 rural women with prehypertension, ages 40-69, enrolled in a healthy eating and activity community-based clinical trial for reducing blood pressure.

RESULTS

Ninety (31%) women had metabolic syndrome, of which 70% were obese by BMI (≥30 kg/m²), 100% by percentage body fat (≥30%), and 100% by revised BMI standards (≥25 kg/m²) cited in current literature. Hierarchical logistic regression models, adjusted for age, income, and education, revealed that higher percentage body fat (P < 0.001) was associated with greater prevalence of metabolic syndrome. Alone, higher fitness lowered the odds of metabolic syndrome by 7% (P < 0.001), but it did not lower the odds significantly beyond the effects of body fat. When dichotomized into "fit" and "unfit" groups, women categorized as "fat" had lower odds of metabolic syndrome if they were "fit" by 75% and 59%, for percentage body fat and revised BMI, respectively.

CONCLUSION

Among rural women with prehypertension, obesity and fitness were associated with metabolic syndrome. Obesity defined as ≥25 kg/m² produced results more consistent with percentage body fat as compared to the ≥30 kg/m² definition.

Prevalence of elevated mean arterial pressure and how fitness moderates its association with BMI in youth

OBJECTIVE

Cardiorespiratory fitness is known to be cardioprotective and its association with the components of the metabolic syndrome in children is becoming clearer. The aim of the present study was to examine the extent to which cardiorespiratory fitness may offset the weight-related association with mean arterial pressure (MAP) in schoolchildren.

DESIGN

Cross-sectional study.

SETTINGS

Schoolchildren from the East of England, U.K.

SUBJECTS

A total of 5983 (48% females) schoolchildren, 10 to 16 years of age, had height, weight and blood pressure measured by standard procedures and cardiorespiratory fitness assessed by the 20 m shuttle-run test. Participants were classified as fit or unfit using internationally accepted fitness cut-off points; and as normal weight, overweight or obese based on BMI, again using international cut-off points. Age-adjusted ANCOVA was used to determine the main effects and interaction of fitness and BMI on MAP Z-score. Logistic regression models were used to estimate odds ratios of elevated MAP.

RESULTS

Prevalence of elevated MAP in schoolchildren was 14.8% overall and 35.7% in those who were obese-unfit. Approximately 21% of participants were overweight and 5% obese, while 23% were classified as unfit. MAP generally increased across BMI categories and was higher in the aerobically unfit participants. Obese-fit males had lower MAP compared with obese-unfit males (P < 0.001); this trend was similar in females (P = 0.05).

CONCLUSIONS

Increasing fitness level may have a positive impact on the weight-related elevations of MAP seen in obese and overweight schoolchildren.

An overview of the contribution of fatness and fitness factors, and the role of exercise, in the formation of health status for individuals who are overweight

Over the last half century there has been an epidemic of diminished health status induced by what seems as a concurrent rise in a population of individuals that are overfat. During the past few decades, the use of exercise has become a staple in the prevention and treatment options for the retarding the development of health issues pertaining to individuals who are overweight, overfatness or experience obesity. However, there are few studies and reviews look at the global issues surrounding the metabolic and hormone consequences of overfatness and the interaction of exercise with adiposity in humans developing the health status for the individual. This review offers an insight into our current understanding of health issues pertaining to metabolic and hormonal disruption related to overfatness and the treatment effect that exercise, especially resistance exercise, can have on impacting the health status, and overall well-being, for individuals who are overfat, regardless of body compositional changes leading toward a lessening of diseased state, and eventually a return to a normal health status for the individual.

Walks4work: rationale and study design to investigate walking at lunchtime in the workplace setting

Background

Following recruitment of a private sector company, an 8 week lunchtime walking intervention was implemented to examine the effect of the intervention on modifiable cardiovascular disease risk factors, and further to see if walking environment had any further effect on the cardiovascular disease risk factors.

Methods

For phase 1 of the study participants were divided into three groups, two lunchtime walking intervention groups to walk around either an urban or natural environment twice a week during their lunch break over an 8 week period. The third group was a waiting-list control who would be invited to join the walking groups after phase 1. In phase 2 all participants were encouraged to walk during their lunch break on self-selecting routes. Health checks were completed at baseline, end of phase 1 and end of phase 2 in order to measure the impact of the intervention on cardiovascular disease risk. The primary outcome variables of heart rate and heart rate variability were measured to assess autonomic function associated with cardiovascular disease. Secondary outcome variables (Body mass index, blood pressure, fitness, autonomic response to a stressor) related to cardiovascular disease were also measured. The efficacy of the intervention in increasing physical activity was objectively monitored throughout the 8-weeks using an accelerometer device.

Discussion

The results of this study will help in developing interventions with low researcher input with high participant output that may be implemented in the workplace. If effective, this study will highlight the contribution that natural environments can make in the reduction of modifiable cardiovascular disease risk factors within the workplace.

Changes in fitness and fatness on the development of cardiovascular disease risk factors hypertension, metabolic syndrome, and hypercholesterolemia

OBJECTIVES

This study sought examine the independent and combined associations of changes in fitness and fatness with the subsequent incidence of the cardiovascular disease (CVD) risk factors of hypertension, metabolic syndrome, and hypercholesterolemia.

BACKGROUND

The relative and combined contributions of fitness and fatness to health are controversial, and few studies are available on the associations of changes in fitness and fatness with the development of CVD risk factors.

METHODS

We followed up 3,148 healthy adults who received at least 3 medical examinations. Fitness was determined by using a maximal treadmill test. Fatness was expressed by percent body fat and body mass index. Changes in fitness and fatness between the first and second examinations were categorized into loss, stable, or gain groups.

RESULTS

During the 6-year follow-up after the second examination, 752, 426, and 597 adults developed hypertension, metabolic syndrome, and hypercholesterolemia, respectively. Maintaining or improving fitness was associated with lower risk of developing each outcome, whereas increasing fatness was associated with higher risk of developing each outcome, after adjusting for possible confounders and fatness or fitness for each other (all p for trend <0.05). In the joint analyses, the increased risks associated with fat gain appeared to be attenuated, although not completely eliminated, when fitness was maintained or improved. In addition, the increased risks associated with fitness loss were also somewhat attenuated when fatness was reduced.

CONCLUSIONS

Both maintaining or improving fitness and preventing fat gain are important to reduce the risk of developing CVD risk factors in healthy adults.

Adiposity and age explain most of the association between physical activity and fitness in physically active men

BACKGROUND

To determine if there is an association between physical activity assessed by the short version of the International Physical Activity Questionnaire (IPAQ) and cardiorespiratory and muscular fitness.

METHODOLOGY/PRINCIPAL FINDINGS

One hundred and eighty-two young males (age range: 20-55 years) completed the short form of the IPAQ to assess physical activity. Body composition (dual-energy X-Ray absorptiometry), muscular fitness (static and dynamic muscle force and power, vertical jump height, running speed [30 m sprint], anaerobic capacity [300 m running test]) and cardiorespiratory fitness (estimated VO(2)max: 20 m shuttle run test) were also determined in all subjects. Activity-related energy expenditure of moderate and vigorous intensity (EEPA(moderate) and EEPA(vigorous), respectively) was inversely associated with indices of adiposity (r = -0.21 to -0.37, P<0.05). Cardiorespiratory fitness (VO(2)max) was positively associated with LogEEPA(moderate) (r = 0.26, P<0.05) and LogEEPA(vigorous) (r = 0.27). However, no association between VO(2)max with LogEEPA(moderate), LogEPPA(vigorous) and LogEEPA(total) was observed after adjusting for the percentage of body fat. Multiple stepwise regression analysis to predict VO(2)max from LogEEPA(walking), LogEEPA(moderate), LogEEPA(vigorous), LogEEPA(total), age and percentage of body fat (%fat) showed that the %fat alone explained 62% of the variance in VO(2)max and that the age added another 10%, while the other variables did not add predictive value to the model [VO(2)max  = 129.6-(25.1× Log %fat) - (34.0× Log age); SEE: 4.3 ml.kg(-1). min(-1); R(2) = 0.72 (P<0.05)]. No positive association between muscular fitness-related variables and physical activity was observed, even after adjusting for body fat or body fat and age.

CONCLUSIONS/SIGNIFICANCE

Adiposity and age are the strongest predictors of VO(2)max in healthy men. The energy expended in moderate and vigorous physical activities is inversely associated with adiposity. Muscular fitness does not appear to be associated with physical activity as assessed by the IPAQ.