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Does the fat-but-fit paradigm hold true for all-cause mortality when considering the duration of overweight/obesity? Analyzing the WATCH (Weight, Activity and Time Contributes to Health) Paradigm
... This is plausible as longer durations of overweight/obesity have been associated with greater alterations in left-ventricular functioning [9], as well as more severe obesity (i.e., class 1, class 2) [10], abdominal adiposity [10], hypertension [10], insulin resistance [10][11][12], and elevated triglycerides [10] in comparison to those who have been overweight/obese for shorter durations, even when controlling for physical activity level. This gap in the literature has led to the creation of the WATCH (Weight, Activity and Time Contribute to Health) paradigm [13][14][15][16][17] to assess whether physical activity still mitigates the association with negative health outcomes among those who have being overweight/obese for longer durations. The majority of the work on this WATCH paradigm comes from our research group, and thus, herein we summarize and synthesize our previous work detailing the WATCH paradigm as it relates to various health outcomes (Table 1) spanning different physiological (e.g., cardiovascular disease risk and multi-morbidity) and psychological (i.e., depression and quality of life) parameters. ...
... As we have discussed elsewhere [13][14][15][16][17], all studies included in this overview use data from the National Health and Nutrition Examination Survey to place individuals (ages 36-85 years) into one of six groups as follows: group 1 = active, normal weight now but not 10 years ago; group 2 = inactive, normal weight now and 10 years ago; group 3 = active, overweight now but not 10 years ago; group 4 = active, overweight now and 10 years ago; group 5 = inactive, overweight now but not 10 years ago; group 6 = inactive, overweight now and 10 years ago. These same groups were used for all of the included analyses. ...
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.
... There is consistent evidence to show that, among older adults, high CRF either attenuates or entirely mitigates the harmful effects of BMI in what is described as the "fat-but-fit" paradigm (17,18). Evidence on whether the paradigm might extend to adolescents and young adults is sparse (19,20). ...
Objective:
We examined the association between cardiorespiratory fitness (CRF), body mass index (BMI), incidence of major acute cardiovascular events (MACE), and all-cause mortality (ACM).
Methods:
We conducted a retrospective cohort study involving 212,631 healthy young men aged 16 to 25 years who had undergone medical examination and fitness testing (2.4 km run) from 1995 to 2015. Information on the outcomes of major acute cardiovascular events (MACE) and all-cause mortality (ACM) were obtained from the national registry data.
Results:
During 2,043,278 person-years of follow-up, 371 first MACE and 243 ACM events were recorded. Compared against the first run-time quintile, adjusted hazard ratios (HR) for MACE in the second to fifth quintiles were 1.26 (95% CI 0.84-1.91), 1.60 (95% CI 1.09-2.35), 1.60 (95% CI 1.10-2.33), and 1.58 (95% CI 1.09-2.30). Compared against the "acceptable risk" BMI category, the adjusted HRs for MACE in the "underweight," "increased risk," and "high-risk" categories were 0.97 (95% CI 0.69-1.37), 1.71 (95% CI 1.33-2.21), and 3.51 (95% CI 2.61-4.72), respectively. The adjusted HRs for ACM were increased in participants from the fifth run-time quintile in the "underweight" and "high-risk" BMI categories. The combined associations of CRF and BMI with MACE showed elevated hazard in the "BMI≥23-fit" category, which was more pronounced in the "BMI≥23-unfit" category. The hazards for ACM were elevated across the "BMI<23-unfit," "BMI≥23-fit," and "BMI≥23-unfit" categories.
Conclusion:
Lower CRF and elevated BMI were associated with increased hazards of MACE and ACM. A higher CRF did not fully compensate for elevated BMI in the combined models. CRF and BMI remain important targets for public health intervention in young men.
... It is also important to pay attention to other health behaviours (i.e., diet, sleep, smoking, alcohol consumption) [35], and it may be that study participants focussed predominantly on logging steps and ignored adhering to other important health behaviours. As such, this observation aligns with often used sayings 'you cannot outrun your diet' (or 'outwalk' it) and 'it is better to be fat but fit, than to be thin but unfit' [36]. As we did not expect so many of the participants reporting a chronic disease or overweight, we did not ask any questions about health behaviours other than physical activity. ...
Objective
Sustained engagement with Internet-based behavioural interventions is crucial to achieve successful behaviour change outcomes. As this has been problematic in many interventions, a lot of research has focused on participants with little or no engagement. However, few studies have attempted to understand users with continuous long-term engagement, the so called ‘super engaged users’, and why they keep on using programs when everybody else has long stopped. Therefore, the aim of this research was to qualitatively examine characteristics, usage profile and motivations of super engaged users in the 10,000 Steps program.
Methods
Twenty 10,000 Steps users (10 with more than 1 year of engagement, and 10 with more than 10 years of engagement) participated in semi-structured interviews, that were transcribed and thematically analysed.
Results
Participants were aged 60 years on average, with more than half being overweight/obese and/or suffering from chronic disease despite logging high step counts (219 million steps per participant on average) on the 10,000 Steps platform. Participants indicated that the reasons for sustained use were that engaging the program had become a habit, that the program kept them motivated, and that it was easy to use. Few participants had suggestions for improvement or expressed there were program elements they did not like. Uptake of program innovations (e.g., app-version, use of advanced activity tracker instead of pedometer) was modest among the super engaged users.
Conclusion
The findings from this study emphasise the need for digital health programs to incorporate features that will support the development of habits as soon as participants start to engage with the program. While a program’s usability, user-friendliness and acceptability are important to engage and retain new users, habit formation may be more important for sustained long-term engagement with the behaviour and the program.
... Because the goal of the program is employee health, and activity theoretically translates to better physical, mental, and social wellbeing [1,2,47], we examined if TPB, TAM, and/or the HSA incentive can predict health outcomes. A major criticism of HSAs is that they are only for the 'healthy and wealthy' [37]. ...
Background
Employers have become interested in increasing their employees’ physical activity; however, research has shown that employee participation in wellness programs is typically low.
Method
The study applies Ajzen's Theory of Planned Behavior (TPB) and Davis’ Technology Acceptance Model (TAM) to the implementation of a wearable fitness tracker (WFT) program at a regional public university to examine if the provision of a WFT, as well as the financial incentive of Health Savings Account (HSA) dollars, makes the difference between intention and behavior to engage in more physical activity, is predictive of physical activity and improvements in health, and if health improvements are attributable to program participation.
Results
The TPB constructs of attitude (β = 0.69; P = 0.000) and perceived subjective norms (β = 0.24; P = 0.028), as well as HSA incentive (β = 0.48; P = 0.000), were found to be statistically significant predictors of behavioral intention to engage in the program. Perceived ease of use (β = 0.58; P = 0.014) was the only statistically significant TAM construct related to activity at six weeks. HSA motivation was statistically significant and positively related (β = 0.36; P = 0.000) to physical activity at six weeks. Perceived subjective norms had a positive and statistically significant association with improvements in health at the six-week (β = 0.19; P = 0.090) and one-year follow-up (β = 0.16; P = 0.009). At the one-year mark, the results suggest that though activity levels increased, the reported improvements in health were low-moderate (M = 4.51, SD = 1.51), with 4%−18% of improvements in health attributable to participation in the program.
Conclusions
Understanding what drives or deters participation in a WFT program can inform decisions about the adoption of wellness programs with financial incentives.
... This suggests that fitness tracker use may at least promote maintenance of physical activity levels among adolescents, even if it does not encourage an increase in physical activity levels. Because higher physical activity levels are associated with long-term weight loss and health benefits [12,13,56], this finding supports the importance of using fitness trackers with adolescents who are most likely to benefit from them or finding ways to increase adolescent engagement with fitness trackers. ...
Background:
Fitness trackers can engage users through automated self-monitoring of physical activity. Studies evaluating the utility of fitness trackers are limited among adolescents, who are often difficult to engage in weight management treatment and are heavy technology users.
Objective:
We conducted a pilot randomized trial to describe the impact of providing adolescents and caregivers with fitness trackers as an adjunct to treatment in a tertiary care weight management clinic on adolescent fitness tracker satisfaction, fitness tracker utilization patterns, and physical activity levels.
Methods:
Adolescents were randomized to 1 of 2 groups (adolescent or dyad) at their initial weight management clinic visit. Adolescents received a fitness tracker and counseling around activity data in addition to standard treatment. A caregiver of adolescents in the dyad group also received a fitness tracker. Satisfaction with the fitness tracker, fitness tracker utilization patterns, and physical activity patterns were evaluated over 3 months.
Results:
A total of 88 adolescents were enrolled, with 69% (61/88) being female, 36% (32/88) black, 23% (20/88) Hispanic, and 63% (55/88) with severe obesity. Most adolescents reported that the fitness tracker was helping them meet their healthy lifestyle goals (69%) and be more motivated to achieve a healthy weight (66%). Despite this, 68% discontinued use of the fitness tracker by the end of the study. There were no significant differences between the adolescent and the dyad group in outcomes, but adolescents in the dyad group were 12.2 times more likely to discontinue using their fitness tracker if their caregiver also discontinued use of their fitness tracker (95% CI 2.4-61.6). Compared with adolescents who discontinued use of the fitness tracker during the study, adolescents who continued to use the fitness tracker recorded a higher number of daily steps in months 2 and 3 of the study (mean 5760 vs 4148 in month 2, P=.005, and mean 5942 vs 3487 in month 3, P=.002).
Conclusions:
Despite high levels of satisfaction with the fitness trackers, fitness tracker discontinuation rates were high, especially among adolescents whose caregivers also discontinued use of their fitness tracker. More studies are needed to determine how to sustain the use of fitness trackers among adolescents with obesity and engage caregivers in adolescent weight management interventions.
... In the National Health and Nutrition Examination Survey (NHANES) cohort, self-reported physical activity was associated with lower all-cause mortality independent of overweight/obesity status or duration of overweight/obesity. (Dankel, Loenneke, & Loprinzi, 2016) In Europe, it has been observed that "metabolically healthy" high BMI individuals had lower risk for cardiovascular events (HR ~1.3) than their "metabolically unhealthy" counterparts (HR~2.3-2.5) and had higher risk than their "metabolically healthy" normal weight counterparts (HR=1:referent), suggesting that "metabolically healthy obesity" is not necessarily a benign condition. (Lassale et al., 2018) Since high fitness is associated with health benefits even when adjusting for BMI, (Blair et al., 1996;Carnethon et al., 2009;L. ...
Objectives:
Although physical activity ameliorates the metabolic impact of high body mass index (BMI), runners with BMI≥25 kg/m2 are relatively understudied.This study had two goals: 1) Identify differences in body composition, as measured by dual X-ray absorptiometry (DXA), between overweight (BMI≥25 kg/m2) runners (OWR) and normal weight (BMI<25 kg/m2) runners (NWR) and 2) Examine whether an 90 minute run alters total or regional fat mass, as measured by DXA, in OWR and NWR. We hypothesized that OWR would have higher total body fat than NWR and OWR with greater changes in visceral fat after a prolonged run.
Design:
Body composition analysis before and after a supervised run.
Methods:
We recruited NWR (n=16,F:n=7,28.1±1.4 years, BMI 22.0±0.4 kg/m2, results as mean±SE) and OWR (n=11,F:n=7,32.0±1.6 years, BMI 30.5±1.4kg/m2) participants. DXA based body composition was measured before and after a supervised, 90 minute run at 60% heart rate reserve.
Results:
OWR had higher body fat than NWR in all measured regions.. Both groups did not significantly reduce fat mass at any measured fat depots after the running exposure.
Conclusions:
OWR had higher body fat in all measured regions than NWR. DXA could not demonstrate any acute fat mass changes after a prolonged run.
... Therefore, the purpose of this study was to determine how physical activity, overweight/obesity classification, and importantly, overweight/obesity duration are associated with depressive symptoms. Specifically, and similar to our previous work [27,28], we examined how an individual's current weight status, and the duration in which individuals have been at that specific weight classification, alters the association between physical activity and depressive symptoms. We evaluate six mutually exclusive groups, including: active, normal weight (group 1); inactive, normal weight (group 2); active, obese now but not 10 years ago (group 3); active, obese now and 10 years ago (group 4); inactive, obese now but not 10 years ago (group 5); and inactive, obese now and 10 years ago (group 6). ...
Purpose
Overweight/obese individuals are at an increased risk for depression with some evidence of a bidirectional association. The preventative effects of physical activity among overweight/obese individuals have been well documented; however, less is known on how the duration of overweight/obesity alters the association with negative health outcomes. Therefore, the purpose of this investigation was to determine how the classification, and more specifically duration, of overweight/obesity alters the association between physical activity and depressive symptoms.
Methods
The 2005–2006 National Health and Nutrition Examination Survey (NHANES) data were used (n = 764), and individuals were divided into six mutually exclusive groups based on physical activity status, weight classification (measured BMI), and duration of weight classification (assessed via recall). Multivariable linear and logistic regression analyses were computed to examine odds of depressive symptoms (patient health questionnaire (PHQ)-9) among groups.
Results
After adjusting for covariates, only individuals who were inactive and overweight/obese at the examination and 10 years prior were at an increased odds of depressive symptoms in comparison to those who were active and normal weight (odds ratio (OR) = 2.40; 95 % confidence interval (CI) 1.03, 5.61; p = 0.04).
Conclusion
Physical activity appeared to ameliorate the association with depressive symptoms independent of overweight/obesity classification or duration. The cyclic nature of overweight/obesity and depression (i.e., bidirectional association) appears to increase the odds of depression as the length of overweight/obesity is increased. These results provide support for clinicians to assess not only their clients’ current BMI but also the duration in which they have been at a certain weight classification and to further promote physical activity as a preventative measure against depressive symptoms.
The aim of this study was twofold: first, to investigate whether perceived motor competence (PMC) mediates the relation between actual motor competence (AMC) and physical activity (PA) according to the conceptual model of motor development, and second to examine the role of different motivational regulations (i.e., intrinsic, identified, introjected, and external regulation) in the relationship between PMC and PA. A sample of 504 Spanish students (46.2% girls, 8–12 years old) voluntarily participated in this study. In relation to the first aim, structural equation modeling revealed that PMC indeed mediates the association between AMC and PA. In relation to the second aim, positive associations between AMC and PMC (β = 0.32, p < .001), which in turn was positively related to intrinsic and identified regulations (β = 0.46 and β = 0.43 respectively, p < .001), were found. The model showed direct paths from intrinsic and introjected regulation to PA (β = 0.27 and β = 0.22, p < .05) and indirect paths from PMC through intrinsic motivation to PA (β = . 13, p < .05). This study confirms that intrinsic motivation mediates the association between PMC and PA. Strategies targeting to build and develop children’s AMC and PMC, and fostering children’s intrinsic motivation should be targeted to promote children’s PA engagement and motor development.
More than 30% of U.S. adults are obese or overweight. A program of regular physical activity is recommended as part of an effective lifestyle intervention for weight loss and weight management. However, more than 40% of adults do not engage in sufficient physical activity to realize these beneficial effects on body weight. Physicians may encounter many barriers to counseling physical activity, such as lack of knowledge or self-efficacy for counseling patients about physical activity. Obese individuals may be reluctant to exercise because of weight stigma, physique anxiety, and other factors; therefore, referral to a weight management specialist or clinical exercise physiologist can be helpful in facilitating exercise and assisting in achieving a clinically meaningful weight loss. Exercise has many benefits on physical and mental health and well-being that go well beyond weight loss, and it is for these reasons that exercise is particularly important for overweight and obese individuals.
Purpose:
The "fat-but-fit" paradigm has been evaluated. However, the duration of overweight/obesity within the "fat-but-fit" paradigm (ie, assessing body mass at more than 1 time point) has not been extensively evaluated, which was this study's purpose.
Design:
Cross-sectional.
Setting:
National Health and Nutrition Examination Survey 2003 to 2006.
Participants:
Ages 36 to 85; N = 3621.
Measures:
Physical activity assessed via accelerometry. Medical multimorbidity was assessed via physician diagnosis of 13 chronic diseases. Height and body mass were directly measured for current body mass index (BMI), and 10-year prior BMI was calculated using current height and self-reported weight 10 years prior. Six mutually exclusive groups were created: (1) active, normal weight now and 10 years ago; (2) inactive, normal weight now and 10 years ago; (3) active, overweight/obese now but not 10 years ago; (4) active, overweight/obese now and 10 years ago; (5) inactive, overweight/obese now but not 10 years ago; and (6) inactive, overweight/obese now and 10 years ago.
Analysis:
Logistic regression.
Results:
Compared to group 1, adjusted odds ratios (ORs) were as follows: group 2: OR = 2.0 ( P = .004), group 3: OR = 1.7 ( P = .004), group 4: OR = 2.5 ( P < .001), group 5: OR = 2.9 ( P < .001), and group 6: OR = 4.8 ( P < .001).
Conclusions:
All patterns of weight change/duration and activity level altered the odds of medical multimorbidity, suggesting that the duration of overweight/obesity should also be taken into consideration when assessing the "fat-but-fit" paradigm.
Background:
Skeletal muscle strength and engagement in muscle strengthening activities are each inversely associated with all-cause mortality, however less is known on their relationship with cancer-specific mortality.
Methods:
Data from the 1999-2002 NHANES were used assessing 2,773 individuals ≥50 years. Individuals were dichotomized at the 75(th) percentile for knee extensor strength, and engagement in muscle strengthening activities was acquired through self-report with ≥2 sessions per week were classified as meeting guidelines.
Results:
With respect to cancer-specific mortality, individuals in the upper quartile for muscle strength were at a 50% reduced risk (HR: 0.50; 95% CI:0.29-0.85; p=0.01) and those meeting muscle strengthening activities were at a non-significant 8% reduced risk [HR:0.92; 95% CI:0.45-1.86, p=0.81] after adjusting for covariates.
Conclusions:
Clinicians should routinely assess lower extremity strength and promote engagement in muscle strengthening activities aimed at increasing muscle strength.
Objective:
To examine the cardiometabolic healthy obesity paradigm as it relates to all-cause mortality risk, with effect moderation evaluated for physical activity and demographic characteristics.
Methods:
Data from the 1999-2006 NHANES were used. The analytic sample included 7579 dietary fasting adults (20+ yrs). All-cause mortality was linked with participant data from the National Death Index. Metabolic health was based on fasting levels of triglycerides, high-density lipoprotein cholesterol, glucose and blood pressure. Weight status was determined from measured height and weight. Physical activity was assessed via self-report. Six mutually exclusive groups were evaluated, including 1) Metabolically Healthy and Normal Weight (Referent), 2) Metabolically Healthy and Overweight, 3) Metabolically Healthy and Obese, 4) Metabolically Abnormal and Normal Weight, 5) Metabolically Abnormal and Overweight, and 6) Metabolically Abnormal and Obese. A Cox proportional hazards model was used to evaluate the association between these 6 groups and all-cause mortality.
Results:
The unweighted median follow-up was 103months; 770,568 person-months occurred with an incidence rate of 1.18 deaths per 1000 person-months. When compared to those who were metabolically healthy and of normal BMI, all other metabolic and weight configurations had an increased mortality risk. There was no evidence of effect modification by physical activity or demographic characteristics.
Conclusions:
These findings emphasize the importance of optimizing body habitus and increasing public awareness of the detrimental effects of metabolic abnormalities.
PurposePhysical activity has been shown to attenuate the association between overweight/obesity and deleterious cardiovascular health-related outcomes, with emerging work also taking the duration of overweight/obesity into consideration. No previous work, however, has explored the interrelationships between physical activity, obesity, and obesity duration in the context of cognitive task performance, which was the purpose of this study. Method
Data from the 1999–2002 National Health and Nutrition Examination Survey were used (N = 2322 adults 60–85 yrs). Physical activity was assessed via self-report, with body mass index (BMI) directly measured. Participants were classified into one of eight mutually exclusive groups: (0) normal weight now and 10 years ago and active now (n = 195), (1) normal weight and 10 years ago and inactive now (n = 265), (2) normal weight now but not 10 years ago and active now (n = 46), (3) normal weight now but not 10 years ago and inactive now (n = 123), (4) overweight/obese now but not 10 years ago and active now (n = 117), (5) overweight/obese now but not 10 years ago and inactive now (n = 168), (6) overweight/obese now and 10 years ago and active now (n = 435), and (7) overweight/obese now and 10 years ago and inactive now (n = 973). The digit symbol substitution test (DSST) was employed to assess cognitive task performance. ResultsAfter adjustments, only individuals who were inactive (groups 1, 3, 5, and 7) had significantly lower cognitive task performance. Conclusion
Being inactive, regardless of weight classification and duration of overweight/obesity, was inversely associated with cognitive task performance in this national sample of older adults.
Introduction:
Physical activity may protect against health consequences associated with obesity, yet less is known on how the duration of obesity alters this association, specifically as it relates to leukocyte telomere length.
Methods:
The 1999-2002 NHANES was used to place individuals into 6 mutually exclusive groups based on physical activity status and weight status/duration.
Results:
All active individuals, except for those overweight/obese for longer durations, were associated with longer telomeres in comparison to sedentary individuals.
Conclusions:
Physical activity may attenuate the decline in telomere length associated with obesity, but this protective effect may be negated by prolonged periods of overweight/obesity.
The predictive validity of the Pooled Cohort risk (PCR) equations for cardiovascular disease (CVD)–specific and all-cause mortality among a national sample of US adults has yet to be evaluated, which was this study's purpose. Data from the 1999-2010 National Health and Nutrition Examination Survey were used, with participants followed up through December 31, 2011, to ascertain mortality status via the National Death Index probabilistic algorithm. The analyzed sample included 11,171 CVD-free adults (40-79 years of age). The 10-year risk of a first atherosclerotic cardiovascular disease (ASCVD) event was determined from the PCR equations. For the entire sample encompassing 849,202 person-months, we found an incidence rate of 1.00 (95% CI, 0.93-1.07) all-cause deaths per 1000 person-months and an incidence rate of 0.15 (95% CI, 0.12-0.17) CVD-specific deaths per 1000 person-months. The unweighted median follow-up duration was 72 months. For nearly all analyses (unadjusted and adjusted models with ASCVD expressed as a continuous variable as well as dichotomized at 7.5% and 20%), the ASCVD risk score was significantly associated with all-cause and CVD-specific mortality (P<.05). In the adjusted model, the increased all-cause mortality risk ranged from 47% to 77% based on an ASCVD risk of 20% or higher and 7.5% or higher, respectively. Those with an ASCVD score of 7.5% or higher had a 3-fold increased risk of CVD-specific mortality. The 10-year predicted risk of a first ASCVD event via the PCR equations was associated with all-cause and CVD-specific mortality among those free of CVD at baseline. In this American adult sample, the PCR equations provide evidence of predictive validity.
Objectives:
Multimorbidity and physical inactivity are individually associated with increased mortality risk, but the possibility for physical activity to moderate the multimorbidity-mortality relationship has yet to be investigated.
Methods:
Data from the 1999-2006 NHANES were employed, with 16,091 participants constituting the analytic sample. Participants were followed through 2011, including a median follow-up of 99 months. Physical activity was assessed via self-report with multimorbidity assessed from physician diagnosis.
Results:
After adjustment, for every 1 morbidity increase, participants had a 23% increased risk of all-cause mortality (HR = 1.23; 95% CI: 1.19-1.28; p < 0.001). Multimorbidity mostly remained associated with all-cause mortality across all levels of physical activity, with the exception of those achieving four times the dose of the government guidelines.
Discussion:
With the exception of those who engaged in high levels of self-reported physical activity, physical activity had a minimal effect on the multimorbidity-mortality relationship.
Purpose:
Physical activity has been shown to reduce various health risks associated with obesity; however, it is less known how the duration of overweight/obesity impacts these associations. The purpose of this study was to determine how overweight/obesity status and overweight/obesity duration effects the association between physical activity and health-related quality of life (HRQOL).
Design:
Cross-sectional and retrospective.
Setting:
NHANES 2003-2006.
Subjects:
One thousand five hundred and seventy-eight adults were included in this study.
Measures:
Moderate to vigorous physical activity was defined as ≥ 2020 activity counts in a given minute for ≥ 150 min/week; HRQOL assessed from the CDC HRQOL-4 survey; present BMI was objectively measured and 10 year prior BMI was calculated using self-reported body mass. Six groups were created: (i) physically active, normal weight now and 10 years ago; (ii) physically inactive, normal weight now and 10 years ago; (iii) physically active, overweight/obese now but not 10 years ago; (iv) physically active, overweight/obese now and 10 years ago; (v) physically inactive, overweight/obese now but not 10 years ago and (vi) physically inactive, overweight/obese now and 10 years ago.
Analysis:
Multivariable ordinal regression.
Results:
In comparison to active individuals who were normal weight at the examination and 10 years prior, only those who were inactive and overweight at the examination and 10 years prior had a worse HRQOL; β = 0.91 (95% CI: 0.20-1.63; p = 0.01).
Conclusions:
Among individuals who have been overweight/obese for longer durations, physical activity may help to improve HRQOL.
Diet and/or exercise are routinely advised as methods for weight loss in overweight/obese individuals, particularly those who are at high risk for cardiovascular disease and type 2 diabetes mellitus. However, physical activity and structured exercise programs rarely result in significant loss of body weight or body fat, and weight-loss diets have extraordinarily high recidivism rates. Despite only modest effects on body weight, exercise and ad libitum nutrient-dense diets for overweight/obese individuals have many health benefits, including skeletal muscle adaptations that improve fat and glucose metabolism, and insulin action; enhance endothelial function; have favorable changes in blood lipids, lipoproteins, and hemostatic factors; and reduce blood pressure, postprandial lipemia and glycemia, and proinflammatory markers. These lifestyle-induced adaptations occur independently of changes in body weight or body fat. Thus, overweight/obese men and women who are at increased risk for cardiovascular disease and type 2 diabetes as a result of sedentary lifestyle, poor diet, and excess body weight should be encouraged to engage in regular physical activity and improve their diet, regardless of whether the healthier lifestyle leads to weight loss.
The aim of the article was to review studies on the tracking of physical activity in all phases of life from childhood to late adulthood. The majority of the studies have been published since 2000. The follow-up time in most studies was short, the median being 9 years. In men, the stability of physical activity was significant but low or moderate during all life phases and also in longterm follow-ups. In women, the tracking was lower and in many cases non-significant. Among both sexes, stability seems to be lower in early childhood than in adolescence or in adulthood and lower in transitional phases, such as from childhood to adolescence or from adolescence to adulthood, than in adulthood. However, the differences in the stability of physical activity between age groups and between different phases of life were small. The number of tracking studies utilising objective methods to measure physical activity was so small that systematic differences in stability between self-report and objective methods could not be determined. A factor which caused differences in tracking results was the adjustment of correlations for measurement error and other error variance. Adjusted coefficients were clearly higher than unadjusted ones. However, adjustment was done only in very few studies. If the different methods used for estimating habitual physical activity and the failure to control for important covariates in studies of tracking are taken into account, physical activity appears to track reasonably well also in the longer term, for example from adolescence to adulthood. The results of the tracking studies support the idea that the enhancement of physical activity in children and adolescents is of great importance for the promotion of public health.
Whether higher cardiorespiratory fitness (CRF) attenuates the mortality risk associated with higher adiposity in adults with hypertension (HTN) is poorly understood.
Participants were 13,155 men (mean age, 47.7 (s.d., 9.9) years) who completed a baseline health examination and maximal treadmill exercise test during 1974-2003. All men had HTN at baseline based on resting systolic blood pressure of > or =140 mm Hg or diastolic blood pressure > or =90 mm Hg. CRF was quantified as the duration of a symptom-limited maximal treadmill exercise test, and was grouped for analysis as low (lowest 20%), moderate (middle 40%), and high (upper 40%). Distributions of body mass index (BMI), waist circumference (WC), and percent body fat (%BF) were grouped according to standard clinical guidelines.
During a mean follow-up of 12 years, 883 deaths (355 cardiovascular disease (CVD)) were recorded. Multivariate hazard ratios (HRs) (95% confidence interval) for all-cause mortality, using low-fitness as the reference group, were 0.58 (0.48-0.69) and 0.43 (0.35-0.54) for moderate-fit and high-fit groups, respectively. We observed a similar pattern for CVD mortality. High-fit/obese men had no greater risk of all-cause (1.59 (0.95-2.67)) or CVD (1.23 (0.44-3.41)) death, high-fit/abdominal-obese men had no greater risk for all-cause (1.20 (0.80-1.78)) or CVD (0.62 (0.25-1.53)) death, and high-fit/percent body fat (%BF)-obese men had no greater risk for all-cause (1.19 (0.90-1.56)) or CVD (0.86 (0.52-1.43)) death compared with their high-fit/normal counterparts.
Fitness is a powerful effect modifier in the association of adiposity to mortality in men with HTN, negating the all-cause and CVD mortality risk associated with obesity.
Obesity is an established risk factor for chronic disease and premature death, but losing weight and keeping it off is difficult. Therefore, although obese individuals may know that they are at higher risk of disease and early death, they still may not be able to lose weight and maintain weight loss. Perhaps health professionals should focus less on weight and more on how to enhance and maintain health for people of all sizes and shapes.
(i) To investigate the effects of current obesity, steady weight change and weight fluctuation on physical functioning and (ii) to determine whether associations are independent of coronary heart disease.
Prospective cohort study with body mass index (BMI) measurements at four time points between the ages of 25 and 63 y.
British civil servants based in London offices at baseline.
6895 men and 3413 women aged 35-55 y at baseline.
Physical functioning was assessed using the 10-item scale from the Short Form 36 Health Survey, with a score in the lowest quartile indicating poor physical functioning.
After adjustment for age and confounders (employment grade, smoking, alcohol, exercise and menopausal status), current BMI was monotonically associated with poor physical functioning in women whereas a threshold effect at a BMI of 27 kg/m2 was seen in men. The odds ratio of poor physical functioning was 1.55 (95% confidence interval (CI) 1.02-2.35) amongst women and 1.04 (95% CI 0.77-1.41) amongst men with BMI 23-24.9 kg/m2 compared to those with BMI < 21 kg/m2. Women in the upper, compared to the lower, tertile of steady weight change, had an odds ratio of poor physical functioning of 1.79 (1.24-2.60) after adjustment for age, confounders, current BMI and weight fluctuation. Women in the upper, compared to the lower, tertile of weight fluctuation had an odds ratio of poor physical functioning of 1.70 (1.23-2.34) adjusting for age, confounders, current BMI and steady weight change. Adjustment for the presence of coronary heart disease did not substantially alter any of these associations. Steady weight change and weight fluctuation had no independent effects in men.
Among women, current obesity, steady weight change and weight fluctuation are independently and monotonically associated with poor physical functioning. Development of overt coronary heart disease is unlikely to be the mechanism for these associations.
Recent guidelines for treatment of overweight and obesity include recommendations for risk stratification by disease conditions and cardiovascular disease (CVD) risk factors, but the role of physical inactivity is not prominent in these recommendations.
To quantify the influence of low cardiorespiratory fitness, an objective marker of physical inactivity, on CVD and all-cause mortality in normal-weight, overweight, and obese men and compare low fitness with other mortality predictors.
Prospective observational data from the Aerobics Center Longitudinal Study.
Preventive medicine clinic in Dallas, Tex.
A total of 25714 adult men (average age, 43.8 years [SD, 10.1 years]) who received a medical examination during 1970 to 1993, with mortality follow-up to December 31, 1994.
Cardiovascular disease and all-cause mortality based on mortality predictors (baseline CVD, type 2 diabetes mellitus, high serum cholesterol level, hypertension, current cigarette smoking, and low cardiorespiratory fitness) stratified by body mass index.
During the study period, there were 1025 deaths (439 due to CVD) during 258781 man-years of follow-up. Overweight and obese men with baseline CVD or CVD risk factors were at higher risk for all-cause and CVD mortality compared with normal-weight men without these predictors. Using normal-weight men without CVD as the referent, the strongest predictor of CVD death in obese men was baseline CVD (age- and examination year-adjusted relative risk [RR], 14.0; 95% confidence interval [CI], 9.4-20.8); RRs for obese men with diabetes mellitus, high cholesterol, hypertension, smoking, and low fitness were similar and ranged from 4.4 (95% CI, 2.7-7.1) for smoking to 5.0 (95% CI, 3.6-7.0) for low fitness. Relative risks for all-cause mortality in obese men ranged from 2.3 (95% CI, 1.7-2.9) for men with hypertension to 4.7 (95% CI, 3.6-6.1) for those with CVD at baseline. Relative risk for all-cause mortality in obese men with low fitness was 3.1 (95% CI, 2.5-3.8) and in obese men with diabetes mellitus 3.1 (95% CI, 2.3-4.2) and as slightly higher than the RRs for obese men who smoked or had high cholesterol levels. Low fitness was an independent predictor of mortality in all body mass index groups after adjustment for other mortality predictors. Approximately 50% (n = 1674) of obese men had low fitness, which led to a population-attributable risk of 39% for CVD mortality and 44% for all-cause mortality. Baseline CVD had population attributable risks of 51% and 27% for CVD and all-cause mortality, respectively.
In this analysis, low cardiorespiratory fitness was a strong and independent predictor of CVD and all-cause mortality and of comparable importance with that of diabetes mellitus and other CVD risk factors.
The metabolic syndrome, a concurrence of disturbed glucose and insulin metabolism, overweight and abdominal fat distribution, mild dyslipidemia, and hypertension, is associated with subsequent development of type 2 diabetes mellitus and cardiovascular disease (CVD). Despite its high prevalence, little is known of the prospective association of the metabolic syndrome with cardiovascular and overall mortality.
To assess the association of the metabolic syndrome with cardiovascular and overall mortality using recently proposed definitions and factor analysis.
The Kuopio Ischaemic Heart Disease Risk Factor Study, a population-based, prospective cohort study of 1209 Finnish men aged 42 to 60 years at baseline (1984-1989) who were initially without CVD, cancer, or diabetes. Follow-up continued through December 1998.
Death due to coronary heart disease (CHD), CVD, and any cause among men with vs without the metabolic syndrome, using 4 definitions based on the National Cholesterol Education Program (NCEP) and the World Health Organization (WHO).
The prevalence of the metabolic syndrome ranged from 8.8% to 14.3%, depending on the definition. There were 109 deaths during the approximately 11.4-year follow-up, of which 46 and 27 were due to CVD and CHD, respectively. Men with the metabolic syndrome as defined by the NCEP were 2.9 (95% confidence interval [CI], 1.2-7.2) to 4.2 (95% CI, 1.6-10.8) times more likely and, as defined by the WHO, 2.9 (95% CI, 1.2-6.8) to 3.3 (95% CI, 1.4-7.7) times more likely to die of CHD after adjustment for conventional cardiovascular risk factors. The metabolic syndrome as defined by the WHO was associated with 2.6 (95% CI, 1.4-5.1) to 3.0 (95% CI, 1.5-5.7) times higher CVD mortality and 1.9 (95% CI, 1.2-3.0) to 2.1 (95% CI, 1.3-3.3) times higher all-cause mortality. The NCEP definition less consistently predicted CVD and all-cause mortality. Factor analysis using 13 variables associated with metabolic or cardiovascular risk yielded a metabolic syndrome factor that explained 18% of total variance. Men with loadings on the metabolic factor in the highest quarter were 3.6 (95% CI, 1.7-7.9), 3.2 (95% CI, 1.7-5.8), and 2.3 (95% CI, 1.5-3.4) times more likely to die of CHD, CVD, and any cause, respectively.
Cardiovascular disease and all-cause mortality are increased in men with the metabolic syndrome, even in the absence of baseline CVD and diabetes. Early identification, treatment, and prevention of the metabolic syndrome present a major challenge for health care professionals facing an epidemic of overweight and sedentary lifestyle.
To determine in normal weight, overweight, and obese men the risk of all-cause and cardiovascular disease (CVD) mortality associated with the metabolic syndrome (MetS) and the influence of cardiorespiratory fitness (CRF).
This observational cohort study included 19,173 men who underwent a clinical examination, including a maximal exercise test. MetS was defined according to National Cholesterol Education Program guidelines.
At baseline 19.5% of the men had MetS. The ORs of the metabolic syndrome at baseline were 4.7 (95% CI 4.2-5.3) in overweight and 30.6 (26.7-35.0) in obese men compared with normal weight men. A total of 477 deaths (160 CVD) occurred in 10.2 years of follow-up. The risks of all-cause mortality were 1.11 (0.75-1.17) in normal weight, 1.09 (0.82-1.47) in overweight, and 1.55 (1.14-2.11) in obese men with MetS compared with normal weight healthy men. The corresponding risks for CVD mortality were 2.06 (0.92-4.63) in normal weight, 1.80 (1.10-2.97) in overweight, and 2.83 (1.70-4.72) in obese men with the MetS compared with normal weight healthy men. After the inclusion of CRF in the model, the risks associated with obesity and MetS were no longer significant.
Obesity and MetS are associated with an increased risk of all-cause and CVD mortality; however; these risks were largely explained by CRF.
Randomised controlled trials have shown that exercise training has a mild or moderate favourable effect on many metabolic and cardiovascular risk factors that constitute or are related to the metabolic syndrome (MetS). Epidemiological studies suggest that regular physical activity prevents type 2 diabetes, cardiovascular disease, and premature mortality in large part through these risk factors. Although randomized controlled trials with the prevention or treatment of the MetS as the main outcome have not been published, several large randomized controlled trials provide strong evidence that favourable lifestyle changes, including regular physical activity, are effective in the prevention of type 2 diabetes in individuals who are overweight and have impaired glucose tolerance. Compliance with the current recommendations to increase the total volume of moderate-intensity physical activity and to maintain good cardiorespiratory and muscular fitness appears to markedly decrease the likelihood of developing the MetS, especially in high-risk groups. Walking is the most common form of physical activity--it improves health in many ways and is generally safe. Therefore, brisk walking for at least 30 min daily can be recommended as the principal form of physical activity at the population level. If there are no contraindications, more vigorous physical exercise or resistance training should also be considered to obtain additional health benefits. Unstructured and low-intensity physical activity may also decrease the likelihood of developing the MetS, especially when substituted for sedentary behaviours such as watching television. The measurement of maximal oxygen consumption may provide an efficient means to target even individuals with relatively few metabolic risk factors who may benefit from more intensive intervention.
Involuntary weight gains worsen all elements of the cardiovascular risk profile, including dyslipidemia, hypertension, insulin-resistant glucose intolerance, left-ventricular hypertrophy, hyperuricemia, and elevated fibrinogen. On the basis of data from the Framingham Heart Study and from other studies, it can be concluded that the degree of overweight is related to the rate of development of cardiovascular disease. After 26 y of follow-up in the Framingham study, each SD increment in relative weight was associated with 15% and 22% increases in cardiovascular events in men and women, respectively. Avoidance of weight gain after the age of 25 y is advisable to reduce cardiovascular mortality. There is a great potential benefit to weight loss, suggesting that weight control as a means for preventing and lessening cardiovascular disease become a national health priority. The optimal weight for avoidance of cardiovascular disease and prolonging life corresponds to a body mass index of 22.6 for men and 21.1 for women.
Over the past several decades, more and more research has been published demonstrating the health benefits of physical activity. The benefits have been far ranging-from reducing premature death from all causes of mortality to reducing depression in older adults. This past year, Secretary Michael Leavitt from the US Health and Human Services convened a panel of experts to carefully review all of the scientific evidence for the benefits of physical activity. A 13-member committee was brought together to form the Physical Activity Guidelines Advisory Committee. In June of 2008, the Committee submitted their comprehensive 683-page report to Secretary Leavitt. The technical report was used by the US Department of Health and Human Services to develop the 2008 Physical Activity Guideline for Americans. The inaugural set of Physical Activity Guidelines for Americans was released on October 7, 2008. This article summarizes the events that led up to the development of those Guidelines and provides a brief overview of their key recommendations
In this review, we examine the original obesity paradox phenomenon (i.e. in cardiovascular disease populations, obese patients survive better), as well as three other related paradoxes (pre-obesity, "fat but fit" theory, and "healthy" obesity). An obesity paradox has been reported in a range of cardiovascular and non-cardiovascular conditions. Pre-obesity (defined as a body mass index of 25.0-29.9 kg · m⁻²) presents another paradox. Whereas "overweight" implies increased risk, it is in fact associated with decreased mortality risk compared with normal weight. Another paradox concerns the observation than when fitness is taken into account, the mortality risk associated with obesity is offset. The final paradox under consideration is the presence of a sizeable subset of obese individuals who are otherwise healthy. Consequently, a large segment of the overweight and obese population is not at increased risk for premature death. It appears therefore that low cardiorespiratory fitness and inactivity are a greater health threat than obesity, suggesting that more emphasis should be placed on increasing leisure time physical activity and cardiorespiratory fitness as the main strategy for reducing mortality risk in the broad population of overweight and obese adults.
Given the evidence that regular physical activity produces substantial health benefits, participation in sports, exercise, and recreation is widely encouraged. The objective of this study was to describe participation in sports, exercise, and recreational physical activities among US adults.
Data from 2 national surveys of respondents age 18 years and older were analyzed. Respondents to the American Time Use Survey (ATUS) from 2003 through 2005 (N=45,246) reported all activities on 1 randomly selected survey day. Respondents to the National Health and Nutrition Examination Survey (NHANES) from 1999 through 2004 (N=17,061) reported leisure-time physical activities in the 30 days before the interview.
One-quarter of adults participated in any sport, exercise, or recreational activity on a random day, and 60.9% of adults participated in any leisure-time activity in the previous 30 days. The most common types of activities were walking, gardening and yard work, and other forms of exercise. The sports and recreational activities had typical durations of 1/2 to 3 hours per session, and the exercise activities typically lasted 1 hour or less.
The prevalence of sports, exercise, and recreational physical activities is generally low among US adults; exercise is the most commonly reported type of activity.
Body-mass index (the weight in kilograms divided by the square of the height in meters) is known to be associated with overall mortality. We investigated the effects of age, race, sex, smoking status, and history of disease on the relation between body-mass index and mortality.
In a prospective study of more than 1 million adults in the United States (457,785 men and 588,369 women), 201,622 deaths occurred during 14 years of follow-up. We examined the relation between body-mass index and the risk of death from all causes in four subgroups categorized according to smoking status and history of disease. In healthy people who had never smoked, we further examined whether the relation varied according to race, cause of death, or age. The relative risk was used to assess the relation between mortality and body-mass index.
The association between body-mass index and the risk of death was substantially modified by smoking status and the presence of disease. In healthy people who had never smoked, the nadir of the curve for body-mass index and mortality was found at a body-mass index of 23.5 to 24.9 in men and 22.0 to 23.4 in women. Among subjects with the highest body-mass indexes, white men and women had a relative risk of death of 2.58 and 2.00, respectively, as compared with those with a body-mass index of 23.5 to 24.9. Black men and women with the highest body-mass indexes had much lower risks of death (1.35 and 1.21), which did not differ significantly from 1.00. A high body-mass index was most predictive of death from cardiovascular disease, especially in men (relative risk, 2.90; 95 percent confidence interval, 2.37 to 3.56). Heavier men and women in all age groups had an increased risk of death.
The risk of death from all causes, cardiovascular disease, cancer, or other diseases increases throughout the range of moderate and severe overweight for both men and women in all age groups. The risk associated with a high body-mass index is greater for whites than for blacks.
physical activity guidelines for Americans
USDHHS, 2008. 2008 physical activity guidelines for Americans. USDHHS, Washington
DC.