Physical activity patterns and prevention of weight gain in premenopausal women

Physical Activity and Obesity Risk in Adults in Colombia: The Prospective Urban Rural Epidemiology (PURE) Study

PURPOSE

This study aimed to investigate longitudinal associations between physical activity levels and obesity in adults in Colombia, where participation in large amounts of light-intensity physical activity is a necessity for many people.

METHODS

Participation in moderate- and vigorous-intensity physical activity was assessed from 2005 to 2009, and obesity was assessed from 2011 to 2019 in men and women from the Prospective Urban Rural Epidemiology (PURE) study. Total physical activity level was categorized as low (<600 MET·min·wk -1 ), medium (600-3000 MET·min·wk -1 ), or high (>3000 MET·min·wk -1 ; 600 MET·min·wk -1 is equivalent to 150 min of moderate activity or 75 min of vigorous activity per week). Obesity was defined as body mass index ≥30 kg·m -2 . Analyses were adjusted for age, sex, smoking, socioeconomic status, diet, alcohol, sedentary time, and sleep.

RESULTS

The main analysis included 3086 men and women aged 51 ± 9 yr at baseline (mean ± SD). Compared with the low physical activity group, the odds ratio (95% confidence interval) for obesity was 0.67 (0.53-0.85) in the medium physical activity group and 0.78 (0.62-0.98) in the high physical activity group after adjustment for potential confounders. Smoking is probably a major confounder, and it is noteworthy that similar associations were observed in participants who reported never smoking.

CONCLUSIONS

The PURE study is the only prospective cohort study in Colombia. The present analysis is important because it suggests that even the busy people of Colombia could substantially reduce their risk of obesity by participating in moderate- and vigorous-intensity physical activity.

Health Benefits of Different Sports: a Systematic Review and Meta-Analysis of Longitudinal and Intervention Studies Including 2.6 Million Adult Participants

BACKGROUND

Several reviews have examined the health benefits of participation in specific sports, such as baseball, cricket, cross-country skiing, cycling, downhill skiing, football, golf, judo, rugby, running and swimming. However, new primary studies on the topic have recently been published, and the respective meta-analytic evidence needs to be updated.

OBJECTIVES

To systematically review, summarise and appraise evidence on physical health benefits of participation in different recreational sports.

METHODS

Searches for journal articles were conducted in PubMed/MEDLINE, Scopus, SpoLit, SPORTDiscus, Sports Medicine & Education Index and Web of Science. We included longitudinal and intervention studies investigating physical health outcomes associated with participation in a given sport among generally healthy adults without disability.

RESULTS

A total of 136 papers from 76 studies conducted among 2.6 million participants were included in the review. Our meta-analyses of available evidence found that: (1) cycling reduces the risk of coronary heart disease by 16% (pooled hazard ratio [HR] = 0.84; 95% confidence interval [CI]: 0.80, 0.89), all-cause mortality by 21% (HR = 0.79; 95% CI: 0.73, 0.84), cancer mortality by 10% (HR = 0.90; 95% CI: 0.85, 0.96) and cardiovascular mortality by 20% (HR = 0.80; 95% CI: 0.74, 0.86); (2) football has favourable effects on body composition, blood lipids, fasting blood glucose, blood pressure, cardiovascular function at rest, cardiorespiratory fitness and bone strength (p < 0.050); (3) handball has favourable effects on body composition and cardiorespiratory fitness (p < 0.050); (4) running reduces the risk of all-cause mortality by 23% (HR = 0.77; 95% CI: 0.70, 0.85), cancer mortality by 20% (HR = 0.80; 95% CI: 0.72, 0.89) and cardiovascular mortality by 27% (HR = 0.73; 95% CI: 0.57, 0.94) and improves body composition, cardiovascular function at rest and cardiorespiratory fitness (p < 0.010); and (5) swimming reduces the risk of all-cause mortality by 24% (HR = 0.76; 95% CI: 0.63, 0.92) and improves body composition and blood lipids (p < 0.010).

CONCLUSIONS

A range of physical health benefits are associated with participation in recreational cycling, football, handball, running and swimming. More studies are needed to enable meta-analyses of health benefits of participation in other sports. PROSPERO registration number CRD42021234839.

The Relationship of Diet and Physical Activity with Weight Gain and Weight Gain Prevention in Women of Reproductive Age

Reproductive-age women often see increased weight gain, which carries an increased risk of long-term overweight and obesity and adverse maternal and child health outcomes. Supporting women to achieve optimal weight through lifestyle modification (diet and physical activity) is of critical importance to reduce weight gain across key reproductive life-stages (preconception, pregnancy and postpartum). This review comprehensively summarizes the current state of knowledge on the contribution of diet and physical activity to weight gain and weight gain prevention in reproductive-aged women. Suboptimal diets including a higher proportion of discretionary choices or energy intake from fats, added sugars, sweets or processed foods are associated with higher weight gain, whereas increased consumption of core foods including fruits, vegetables and whole grains and engaging in regular physical activity are associated with reduced weight gain in reproductive age women. Diet and physical activity contributing to excessive gestational weight gain are well documented. However, there is limited research assessing diet and physical activity components associated with weight gain during the preconception and postpartum period. This review highlights the need for further research to identify key dietary and physical activity components targeting the critical windows of reproductive life-stages in women to best guide interventions to prevent weight gain.

[Nutritional advices for postmenopausal woman. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Menopause is a key period for health due to physiological changes, particularly of body composition (with decrease of lean mass and increase of fat mass) and of body fat distribution, leading to a higher risk for bone and muscular health and cardiometabolic health. Nutritional advices, associated to physical activity advices, may partially prevent these effects. The energy balance will be moderately negative if there is a weight gain, while the protein intake will be preserved and a regular physical activity will be increased. A Mediterranean style diet will be beneficial on cardiovascular health. Dairy products will be preserved, but restrictive and dietary exclusion will be avoided.

Composition of time in movement behaviors and weight change in Latinx, Black and white participants

Background

The relationship between time-use behaviors and prospective weight change is poorly understood.

Methods

A subset of Cancer Prevention Study-3 participants (n = 549, 58% women, 66% non-Latinx white) self-reported weight in 2015 and 2018 and completed an accelerometer protocol for seven days. Sedentary time, sleep, light, moderate, and vigorous intensity physical activity (PA) were treated as a compositional variable and multiple linear regression was used to examine associations between activity composition and weight change stratified by sex and race/ethnicity. Compositional isotemporal substitution analysis was used to quantify change in weight associated with reallocating 30 min./day.

Results

Activity composition was associated with weight change among women (p = 0.007), but not men (p = 0.356), and among Latinx (p = 0.032) and white participants (p = 0.001), but not Black participants (p = 0.903). Replacement of 30 min./day sedentary time with moderate-vigorous PA was associated with 3.49 lbs. loss (-6.76, -0.22) in Latinx participants and replacement with sleep was associated with 1.52 (0.25, 2.79) and 1.31 (0.40, 2.21) lbs. gain in white women and men.

Conclusion

The distribution of time spent in daily behaviors was associated with three-year weight change in women, Latinx, and white participants. This was the first longitudinal compositional study of weight change; thus, more studies are needed.

Changes in body composition with a hypocaloric diet combined with sedentary, moderate and high-intense physical activity: a randomized controlled trial

BACKGROUND

There is evidence showing the effectiveness of a hypocaloric diet and the increase in physical activity on weight loss. However, the combined role of these factors, not only on weight loss but also body composition, remains unclear. The purpose of this study was to investigate the effect of a hypocaloric diet on the body composition of obese adult women throughout different degrees of physical activity during a weight loss program.

METHODS

One hundred and seventeen healthy female volunteers were randomly assigned to one of the experimental groups: a control group with a low-level prescription of physical activity (1-4 METs), moderate physical activity group that performed 10.000 steps walking (5-8 METs) and intense physical activity group that trained exercises by at least 70% of VO2max three times a week (> 8 METs). All subjects followed a hypocaloric diet designed with a reduction of 500 kcal/day. Nutritional counseling was provided throughout the study period to help ensure dietary adherence.

RESULTS

We found no differences in body weight compared to moderate and intense physical activity (ßstand. = - 0.138 vs. ßstand. = - 0.139). Body fat was lower in women following an intense activity (ßstand. = - 0.436) than those with moderate exercise (ßstand. = - 0.231). The high-intense activity also increased muscle mass at the end of the intervention, standing out above the moderate activity (ßstand. = 0.182 vs. ßstand. = 0.008).

CONCLUSIONS

These findings indicate that a hypocaloric diet, without prescription of physical activity, is adequate to lose weight in the short term (12 weeks), but physical activity is vital to modify the body composition in women with obesity. Body fat was lower when women practiced a moderate exercise compared to hypocaloric diet only, but an intense physical activity was the most effective protocol to obtain a reduction of body fat and maintain muscle mass.

TRIAL REGISTRATION

The study protocol complied with the Declaration of Helsinki for medical studies, it was approved by the bioethical committee of Córdoba University, in the Department of Health at the Regional Government of Andalusia (Act n°284, ref.4156) and retrospectively registered in clinicaltrials.gov (NCT03833791). Registered 2 January 2019.

Field-Based Tests for the Assessment of Physical Fitness in Children and Adolescents Practicing Sport: A Systematic Review within the ESA Program

High levels of physical fitness (PF) can positively affect both health and cognitive function, thus monitoring its levels in youth can help increase health and quality of life in adult populations later on. This systematic review aims to identify PF field-based tests used in young European populations practicing sport to find tools that are adequate for the considered target involving a new battery within the Enriched Sport Activities (ESA) project. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed. In the 83 identified articles, the main tests used were: vertical/horizontal jumps (for muscular strength/power); push-ups, running at maximum effort, sit-ups (for muscular strength/endurance); multistage non-intermittent and intermittent tests (for aerobic endurance); sit and reach (for flexibility); sprinting and agility T-tests (for speed and agility, respectively); 10 × 5 m shuttle run (SR) (for both speed and agility). Few studies assessed coordination, reaction time, power, and balance. Although the selected tests are widely used and validated, they do not determine all PF aspects and do not reflect sport-specific features. A final decision was made for the inclusion of the following tests: standing broad jump, seated medicine ball throw, 20 m SR test, 30 m sprint, Illinois test, and a new test, i.e., the crunning test, to assess different skill-related components at once. The use of this combination of tests allows for the assessment of all PF components and can help planning effective training programs and cultivate sporting talent.

Pain Intensity And Attribution Mediate The Impact Of Patient Weight And Gender On Activity Recommendations For Chronic Pain

BACKGROUND AND PURPOSE

Despite the notable benefits of physical activity for chronic pain, a large proportion of patients with chronic pain report that they do not receive activity-related recommendations from their providers. Research suggests that patient factors such as weight and gender influence activity-related recommendations for chronic pain. Research also suggests that appraisals of the intensity and cause of pain may explain these weight and gender effects. We investigated the influence of patient weight and gender on observers' likelihood of recommending activity-related treatments for pain. We also explored the mediating effects of observers' ratings of pain severity and the extent to which pain was due to medical and lifestyle factors (pain attribution).

PATIENTS AND METHODS

Healthy young adults (N=616; 76% female) viewed videos (Ghent Pain Videos of Daily Activities) and vignettes of 4 patients with chronic back pain performing a standardized functional task. Patients varied by gender (female, male) and weight (normal, obese), but were otherwise equivalent on demographic characteristics and pain behaviors. Participants rated how much pain they perceived the patients to be experiencing, the extent to which they attributed the pain to medical and lifestyle factors, and their likelihood of recommending exercise, physical therapy (PT), and rest.

RESULTS

Patient weight and gender significantly interacted to influence exercise, PT, and rest recommendations. Both pain intensity and pain attribution mediated the relationships between patient weight and activity recommendations; however, these mediation effects differed across gender and recommendation type.

CONCLUSION

Patient weight and gender influenced laypeople's activity recommendations for chronic pain. Moreover, the results suggest that observers' perceptions of pain intensity and pain attributions are mechanisms underlying these effects. If these findings are replicated in providers, interventions may need to be developed to reduce provider biases and increase their recognition of the benefits of physical activity for chronic pain.

Reallocating bouted sedentary time to non-bouted sedentary time, light activity and moderate-vigorous physical activity in adults with prediabetes and type 2 diabetes

Aim

The aim of this study was to investigate the potential associations of reallocating 30 minutes sedentary time in long bouts (>60 min) to sedentary time in non-bouts, light intensity physical activity (LPA) and moderate- to vigorous physical activity (MVPA) with cardiometabolic risk factors in a population diagnosed with prediabetes or type 2 diabetes.

Methods

Participants diagnosed with prediabetes and type 2 diabetes (n = 124, 50% men, mean [SD] age = 63.8 [7.5] years) were recruited to the physical activity intervention Sophia Step Study. For this study baseline data was used with a cross-sectional design. Time spent in sedentary behaviors in bouts (>60 min) and non-bouts (accrued in <60 min bouts) and physical activity was measured using the ActiGraph GT1M. Associations of reallocating bouted sedentary time to non-bouted sedentary time, LPA and MVPA with cardiometabolic risk factors were examined using an isotemporal substitution framework with linear regression models.

Results

Reallocating 30 minutes sedentary time in bouts to MVPA was associated with lower waist circumference (b = -4.30 95% CI:-7.23, -1.38 cm), lower BMI (b = -1.46 95% CI:-2.60, -0.33 kg/m2) and higher HDL cholesterol levels (b = 0.11 95% CI: 0.02, 0.21 kg/m². Similar associations were seen for reallocation of sedentary time in non-bouts to MVPA. Reallocating sedentary time in bouts to LPA was associated only with lower waist circumference.

Conclusion

Reallocation of sedentary time in bouts as well as non-bouts to MVPA, but not to LPA, was beneficially associated with waist circumference, BMI and HDL cholesterol in individuals with prediabetes and type 2 diabetes. The results of this study confirm the importance of reallocation sedentary time to MVPA.

Association between Meeting Physical Activity Guidelines and Mortality in Korean Adults: An 8-year Prospective Study

PURPOSE

Although previous studies have investigated the association between physical activity and various health outcomes, limited information is available on the effect of meeting new governmental guidelines for physical activity on the risk of mortality in Korean adults. This study aimed to examine the prospective association between meeting these guidelines and all-cause mortality during an 8-year follow-up using a large nationwide sample of middle-aged and older adults in Korea.

METHODS

This prospective study was conducted based on the Korean Longitudinal Study of Ageing. The study participants included 9,177 adults aged 45 years or older at baseline, and all participants were monitored in a 2-year cycle during an 8-year period (70,873 person-years). The risk of mortality was analyzed by determining physical activity levels using the Cox proportional hazard models, and the hazard ratio (HR) and 95% confidence interval (CI) were estimated using Cox models.

RESULTS

A statistically significant effect of physical activity on the reduced risk of mortality was observed in cases in which the participants met the guidelines compared to the inactive group (HR: 0.68, 95% CI: 0.58-0.81 vs. the inactive group). A strong association between meeting the recommended physical activity levels and the reduced risk of mortality was also found for non-smokers (HR: 0.62; 95% CI: 0.51-0.76 vs. the inactive group), but not for current smokers (HR: 0.93; 95% CI: 0.67-1.29 vs. the inactive group).

CONCLUSION

Meeting physical activity guidelines was associated with a decreased risk of all-cause mortality for Korean adults. Our results also suggest that smoking reduces the protective effect of physical activity on the risk of mortality.

Physical Activity for the Prevention of Cardiovascular Diseases

Over the last decade, the quantity and quality of scientific literature examining the relationship between physical activity (PA) and cardiovascular diseases (CVD) have significantly increased. Data from the literature now unequivocally show that physical inactivity is one of the major risk factors for CVD. It is believed that obesity, the prevalence of which has tripled over the last three decades, and physical inactivity among children are the main factors that will increase the prevalence of CVD in this century. The cardiovascular benefits of exercise are multifactorial and include important systemic effects on skeletal muscle, the peripheral vasculature, metabolism, and neurohumoral systems, as well as beneficial alterations within the myocardium itself. Thus, exercise does much more than change traditional risk factors, such as blood pressure, blood lipids, glucose tolerance and insulin resistance, metabolic syndrome, and overweight and obesity. Evidence from epidemiologic studies suggests that the preventive effects of PA may be achieved by 150 minutes of moderate PA a week, while increases in the intensity and volume of exercise lead to further health benefits. This dose–response gradient is curvilinear, with the largest gains from the first hour of weekly exercise. However, although much progress has been made in this field, existing studies performed on human subjects do not clearly show what type, intensity, and duration of exercise is most beneficial to cardiovascular fitness and metabolic optimization. Animal-based exercise studies may provide more information and help to elucidate the abilities of different training regimens to reduce the risk of CVD.

Determinants and Consequences of Obesity

OBJECTIVES

To review the contribution of the Nurses' Health Studies (NHS and NHS II) in addressing hypotheses regarding risk factors for and consequences of obesity.

METHODS

Narrative review of the publications of the NHS and NHS II between 1976 and 2016.

RESULTS

Long-term NHS research has shown that weight gain and being overweight or obese are important risk factors for type 2 diabetes, cardiovascular diseases, certain types of cancers, and premature death. The cohorts have elucidated the role of dietary and lifestyle factors in obesity, especially sugar-sweetened beverages, poor diet quality, physical inactivity, prolonged screen time, short sleep duration or shift work, and built environment characteristics. Genome-wide association and gene-lifestyle interaction studies have shown that genetic factors predispose individuals to obesity but that such susceptibility can be attenuated by healthy lifestyle choices. This research has contributed to evolving clinical and public health guidelines on the importance of limiting weight gain through healthy dietary and lifestyle behaviors.

CONCLUSIONS

The NHS cohorts have contributed to our understanding of the risk factors for and consequences of obesity and made a lasting impact on clinical and public health guidelines on obesity prevention.

Long-term Effects of Physical Activity Level on Changes in Healthy Body Mass Index Over 12 Years in Young Adult Women

OBJECTIVES

To examine the effects of overall level and timing of physical activity (PA) on changes from a healthy body mass index (BMI) category over 12 years in young adult women.

PATIENTS AND METHODS

Participants in the Australian Longitudinal Study on Women's Health (younger cohort, born 1973-1978) completed surveys between 2000 (age 22-27 years) and 2012 (age 34-39 years). Physical activity was measured in 2000, 2003, 2006, and 2009 and was categorized as very low, low, active, or very active at each survey, and a cumulative PA score for this 9-year period was created. Logistic regression was used to examine relationships between PA accumulated across all surveys (cumulative PA model) and PA at each survey (critical periods PA model), with change in BMI category (from healthy to overweight or healthy to obese) from 2000 to 2012.

RESULTS

In women with a healthy BMI in 2000, there were clear dose-response relationships between accumulated PA and transition to overweight (P=.03) and obesity (P<.01) between 2000 and 2012. The critical periods analysis indicated that very active levels of PA at the 2006 survey (when the women were 28-33 years old) and active or very active PA at the 2009 survey (age 31-36 years) were most protective against transitioning to overweight and obesity.

CONCLUSION

These findings confirm that maintenance of very high PA levels throughout young adulthood will significantly reduce the risk of becoming overweight or obese. There seems to be a critical period for maintaining high levels of activity at the life stage when many women face competing demands of caring for infants and young children.

Assessing factors related to waist circumference and obesity: application of a latent variable model

Background. Because the use of BMI (Body Mass Index) alone as a measure of adiposity has been criticized, in the present study our aim was to fit a latent variable model to simultaneously examine the factors that affect waist circumference (continuous outcome) and obesity (binary outcome) among Iranian adults. Methods. Data included 18,990 Iranian individuals aged 20–65 years that are derived from the third National Survey of Noncommunicable Diseases Risk Factors in Iran. Using latent variable model, we estimated the relation of two correlated responses (waist circumference and obesity) with independent variables including age, gender, PR (Place of Residence), PA (physical activity), smoking status, SBP (Systolic Blood Pressure), DBP (Diastolic Blood Pressure), CHOL (cholesterol), FBG (Fasting Blood Glucose), diabetes, and FHD (family history of diabetes). Results. All variables were related to both obesity and waist circumference (WC). Older age, female sex, being an urban resident, physical inactivity, nonsmoking, hypertension, hypercholesterolemia, hyperglycemia, diabetes, and having family history of diabetes were significant risk factors that increased WC and obesity. Conclusions. Findings from this study of Iranian adult settings offer more insights into factors associated with high WC and high prevalence of obesity in this population.

Prospective association between body composition, physical activity and energy intake in young adults

BACKGROUND/OBJECTIVES

Despite considerable research on the association between physical activity (PA) and body composition, there remains limited information on the directionality of the relationship. The present study examined the prospective associations among objectively measured PA, energy intake (EI) and body composition.

SUBJECTS/METHODS

A convenience sample of 430 adults (49% male) between 21 and 35 years of age was followed over 1 year with repeated measurements taken every 3 months. BMI (kg/m(2)) and percent body fat (%BF) were calculated based on anthropometric measurements and dual energy X-ray absorptiometry. A multi-sensor device was worn over a period of 10 days to estimate total daily energy expenditure and time spent in different intensities. EI was calculated based on change in body composition and total daily energy expenditure.

RESULTS

A total of 379 participants provided valid data. On average, participants experienced a significant weight gain of 1.2±4.3 kg during the 12-month observation period, which was associated with an increase in %BF (0.8±3.2 %). Average time spent in moderate-to-vigorous PA (MVPA) decreased significantly, whereas EI remained constant. Optimal linear mixed models, adjusting for age and sex, showed an inverse effect of MVPA on BMI and %BF, whereas EI only directly affected BMI (P<0.001). There was also a significant inverse effect of BMI and %BF on MVPA (P<0.001).

CONCLUSIONS

Results of this study indicate an inverse reciprocal association between MVPA and measures of adiposity. Thus, primary preventive actions are warranted to avoid excess weight gain, which may result in a vicious cycle of weight gain and low PA.

The Psychometric Properties of the Midlife Women's Symptom Index

OBJECTIVE

To evaluate the psychometric properties of the Midlife Women's Symptom Index (MSI) among four racial/ethnic groups of midlife women in the United States.

DESIGN

A secondary data analysis.

SETTING

Internet communities/groups.

PARTICIPANTS

A total of 494 midlife women with symptoms of menopause who self-reported using an Internet survey and completed all sections of the MSI questionnaire.

METHODS

Data were collected from January 1, 2008 to December 31, 2010. The psychometric properties of the MSI were evaluated using measures of internal consistency, item-total correlation coefficients, and discriminant validity.

RESULTS

There were statistically significant differences in marital status, employment, income, religion, country of birth, level of education, diagnosed disease, and self-reported health status across the four racial/ethnic groups. The Kuder-Richardson Formula 20 (KR-20) coefficients for the three subscales of the MSI prevalence section (i.e., physical, psychological, and psychosomatic) ranged from 0.58 (psychosomatic symptoms in Whites) to 0.91 (psychological symptoms in Asian Americans). The Cronbach's alpha coefficients for the three subscale scores ranged from 0.60 (psychosomatic symptoms in Whites) to 0.93 (psychological symptoms in Asian Americans). The mean scores of the MSI differed significantly by race/ethnicity among midlife women of each menopausal status, except for the prevalence section of the psychosocial symptoms.

CONCLUSION

The MSI has demonstrated an acceptable reliability and appropriate discriminant validity across the four racial/ethnic groups, except in the domain of psychosomatic symptoms. Health care providers as well as researchers could use the MSI to assess the symptoms of menopause of midlife women from diverse racial/ethnic backgrounds.

Obesity and Related Factors in Iran: The STEPS Survey, 2011

Background:

To date, no study has addressed the association between race/ethnicity and obesity considering other sociodemographic and lifestyle factors in Iran.

Objectives:

The current study aimed to study lifestyle and the environmental factors affecting obesity in the Iranian subjects of the STEPS Survey, 2011.

Patients and Methods:

The study was conducted on 8639 subjects (aged ≥ 20 years) in the STEPS Survey 2011 in Iran under supervision of the World Health Organization (WHO). Height and body weight were measured following the standardized procedures. Generalized Estimating Equations (GEE) method was used to examine factors associated with obesity. The examined variables were age, gender, race/ethnicity, place of residence, employment status, physical activity, smoking status, and educational level.

Results:

Overall, 22.3% of the subjects were obese. In a GEE model, a healthy weight status among adults was associated with being younger, male, in a rural residence, employees, spending more time engaged in physical activity, being a smoker and having a moderate or high level of education. These associations were statistically significant after adjusting for other variables.

Conclusions:

The study results suggest a need for targeted interventions and continued surveillance for the Iranian adults.

Patterns of physical activity and sedentary behavior in a representative sample of a multi-ethnic South-East Asian population: a cross-sectional study

Background

Few studies have investigated patterns of physical activity in a multi-ethnic Asian urban population. Even less is known about sedentary behaviors in these populations. The present study examined the prevalence of physical activity, exercise and sedentary behavior. In addition, it investigated socio-demographic correlates and the contribution of different domains towards overall physical activity.

Methods

Data of 2319 participants from the population-based cross-sectional Singapore Health 2012 study were analyzed. Physical activity, exercise and sedentary behavior were assessed using the Global Physical Activity Questionnaires. A modified Cox regression model was used to estimate the relative prevalence rates (PR) for overall physical activity, leisure-time exercise and high level of sedentary behavior by socio-demographic factors.

Results

Overall, 73.8% of participants met physical activity guidelines, 24.3% did regular leisure-time exercise and 37.0% reported high levels of sedentary behavior. Travel-related activities contributed about half of the total physical activity. There was a consistent association between age of participants with physical activity and exercise. Older participants were less likely to meet the guidelines (PR = 0.74, 95% C I = 0.61 – 0.91) than younger participants. The prevalence of regular exercise was lowest among 30 to 39 years aged participants (PR = 0.62, 95% CI = 0.45 – 0.86). Females exercised less regularly (PR = 0.63, 95% C I = 0.51 – 0.76) than males. Participants with higher education exercised regularly (PR = 2.08, 95% CI = 1.45 – 2.99) than participants with lower education. Employment status was consistently associated with exercise and high levels of sedentary behavior. Participants who were not in full-time employment exercised more regularly (PR = 1.45, 95% CI = 1.1 – 1.92) and were less likely to report high levels of sedentary behavior (PR = 0.65, 95% CI = 0.44 – 0.97) than those in full-time employment.

Conclusions

Our population-based study suggests a need to encourage overall physical activity but, particularly regular leisure-time exercise, especially among middle-aged, females and those with lower levels of education and full-time employment. Strategies targeting workplaces may be important to reduce high levels of sedentary behavior.

Exercise during pregnancy and its association with gestational weight gain

We examined the association between exercise during pregnancy and meeting gestational weight gain recommendations. Data came from the 2009 South Carolina Pregnancy Risk Assessment Monitoring System (n = 856). Women reported their participation in exercise/sports activities before and during pregnancy, including the number of months and types of exercise. We developed an exercise index (EI), the product of the number of months spent in exercise and average metabolic equivalents for specific exercise. The 2009 Institute of Medicine's guideline was used to categorize gestational weight gain into three classes: inadequate, adequate, and excessive. Multinomial logistic regression models were used to adjust for confounders. Over 46 % of women exceeded the recommended weight gain during pregnancy. Nearly one third (31.9 %) of women reported exercising ≥3 times a week at any time during pregnancy. Compared to women who did not report this level of exercise during pregnancy, exercising women were more likely to meet gestational weight gain recommendations (32.7 vs. 18.7 %) and had a lower odds of excessive gestational weight gain [adjusted odds ratio (AOR) 0.43, 95 % confidence interval 0.24-0.78]. Women with an EI above the median value of those women who exercised or women who exercised ≥3 times a week for 6-9 months during pregnancy had lower odds of excessive gestational weight gain (AOR for EI 0.20, 0.08-0.49; AOR for months 0.26, 0.12-0.56, respectively). Our findings support the need to promote or increase exercise during pregnancy to reduce the high proportion of women who are gaining excessive weight.

Weight training, aerobic physical activities, and long-term waist circumference change in men

OBJECTIVE

Findings on weight training and waist circumference (WC) change are controversial. This study examined prospectively whether weight training, moderate to vigorous aerobic activity (MVAA), and replacement of one activity for another were associated with favorable changes in WC and body weight (BW).

METHODS

Physical activity, WC, and BW were reported in 1996 and 2008 in a cohort of 10,500 healthy U.S. men in the Health Professionals Follow-up Study. Multiple linear regression models (partition/substitution) to assess these associations were used.

RESULTS

After adjusting for potential confounders, a significant inverse dose-response relationship between weight training and WC change (P-trend <0.001) was observed. Less age-associated WC increase was seen with a 20-min/day activity increase; this benefit was significantly stronger for weight training (-0.67 cm, 95% CI -0.93, -0.41) than for MVAA (-0.33 cm, 95% CI -0.40, -0.27), other activities (-0.16 cm, 95% CI -0.28, -0.03), or TV watching (0.08 cm, 95% CI 0.05, 0.12). Substituting 20 min/day of weight training for any other discretionary activity had the strongest inverse association with WC change. MVAA had the strongest inverse association with BW change (-0.23 kg, 95% CI -0.29, -0.17).

CONCLUSIONS

Among various activities, weight training had the strongest association with less WC increase. Studies on frequency/volume of weight training and WC change are warranted.

Physical Activity and Health in Women

Medical authorities advise US adults to perform a minimum of 30 minutes of moderate-intensity aerobic physical activity on most days of the week to improve health and reduce risk for many chronic conditions. New findings from epidemiologic studies suggest that physical activity not only reduces the risk of developing coronary heart disease, stroke, and type 2 diabetes but also may prevent certain cancers (including colon and breast cancer), osteoporotic fracture, falls, cognitive decline, mood disturbances, and adverse pregnancy outcomes. Physical activity is important for regulating body weight, but many cardiometabolic benefits of exercise are independent of such regulation. This article reviews recent epidemiologic evidence on physical activity with respect to a variety of health outcomes in women and concludes with guidance for clinicians seeking to boost activity levels in sedentary patients. However, additional research is needed on features of individual- and community-based interventions and policies that successfully promote healthful levels of physical activity.

Reducing TV watching during adult obesity treatment: two pilot randomized controlled trials

The more time adults spend being sedentary, the greater the risk of obesity. The effect of reducing television (TV) watching, a prominent sedentary behavior, on weight loss has not been tested in an adult standard behavioral obesity intervention, and the mechanisms by which reducing TV watching influences energy balance behaviors are not well understood. Two, 8-week, pilot, randomized controlled trials were conducted examining the effect of a reduced TV watching prescription on energy balance behaviors and weight loss within an adult standard behavioral obesity intervention. In the first study, participants (n=24) were randomized into one of two conditions: (a) reduce energy intake and increase moderate to vigorous physical activity (MVPA) (INCREASE PA); or (b) reduce energy intake and decrease TV watching (DECREASE TV). As findings from the first pilot study did not show an increase in MVPA in the DECREASE TV group, the second study was designed to examine the effect of adding a reduced TV prescription to a standard intervention to optimize outcomes. In Pilot Study 2, participants (n=28) were randomized to INCREASE PA or to INCREASE PA+DECREASE TV. Outcomes included objectively measured TV watching and MVPA, self-reported light physical activity (LPA-Pilot Study 2 only), self-reported dietary intake while watching TV, and weight. Conditions with TV watching prescriptions significantly reduced TV watching. Both studies showed medium to large effect sizes for conditions with TV watching prescriptions to show greater reductions in dietary intake while watching TV. Pilot Study 1 found a trend for an increase in MVPA in INCREASE PA and Pilot Study 2 found significant increases in MVPA in both conditions. Pilot Study 2 found a significant increase in LPA in the INCREASE PA+DECREASE TV. Results indicate adding a TV watching prescription to a standard obesity intervention did not enhance increases in MVPA, but may assist with reducing dietary intake while TV watching and increasing LPA. Future research should examine the effect of reducing TV watching during obesity treatment over a longer time frame in a larger sample.

The Midwest Exercise Trial for the Prevention of Weight Regain: MET POWeR

Weight reduction in overweight and obese individuals results in physiological and behavioral changes that make the prevention of weight regain more difficult than either initial weight loss or the prevention of weight gain. Exercise is recommended for the prevention of weight regain by both governmental agencies and professional organizations. To date, the effectiveness of exercise recommendations for the prevention of weight regain has not been evaluated in a properly designed, adequately powered trial. Therefore, we will conduct a randomized trial to evaluate the effectiveness of 3 levels of exercise on the prevention of weight regain, in initially overweight and obese sedentary men and women. Participants will complete a 3 month weight loss intervention of decreased energy intake (EI) and increased exercise (100 min/week). Participants achieving clinically significant weight loss (≥ 5% of initial weight), will then be randomly assigned to 12 months of verified exercise at 3 levels (150, 225 or 300 min/week). This study will evaluate: 1) the effectiveness of 3 levels of exercise on the prevention of weight regain over 12 months subsequent to clinically significant weight loss (≥ 5%); 2) gender differences in weight regain in response to 3 levels of exercise; and 3) potential compensatory changes in daily physical activity (PA) and EI on weight regain in response to the 3 levels of exercise. The results of this investigation will provide information to develop evidence-based recommendations for the level of exercise associated with the prevention of weight regain.

Physical activity and the incidence of obesity in young African-American women

BACKGROUND

Obesity occurs more commonly among African-American women than among other racial/ethnic groups, and most weight gain occurs before middle age.

PURPOSE

The study prospectively investigated the relationship of vigorous exercise and brisk walking to the incidence of obesity (BMI ≥ 30) among African-American women aged <40 years.

METHODS

During 1995-2009 in the Black Women's Health Study, the current authors followed 20,259 African-American women who were aged <40 years and not obese at baseline. BMI, exercise, and walking were assessed at baseline and on biennial follow-up questionnaires. Data for BMI were collected through 2009. Data for exercise and walking were collected through 2007. Validation and reproducibility data indicated that reporting was more accurate for vigorous exercise than for brisk walking. Cox proportional hazards models estimated incidence rate ratios (IRRs) and 95% CIs of incident obesity for hours/week of vigorous exercise and walking relative to "little or no exercise" (<1 hour/week of vigorous exercise and <1 hour/week of brisk walking). The analyses were conducted in 2012.

RESULTS

The incidence of obesity decreased with increasing vigorous exercise; the IRR was 0.77 (95% CI=0.69, 0.85) for ≥ 7 hours/week relative to little or no exercise; the IRRs were reduced both among women with a healthy weight (BMI <25) at baseline and among women who were overweight (BMI 25-<30) at baseline. The IRRs for brisk walking for exercise and walking for transport were <1.0 for most levels of walking, but without clear trends of decreasing risk with increasing time spent walking.

CONCLUSIONS

The results suggest that vigorous exercise may reduce the incidence of obesity among young African-American women. Results for brisk walking were inconclusive.

Behavioral lifestyle intervention in the treatment of obesity

This article provides an overview of research regarding adult behavioral lifestyle intervention for obesity treatment. We first describe two trials using a behavioral lifestyle intervention to induce weight loss in adults, the Diabetes Prevention Program (DPP) and the Look AHEAD (Action for Health in Diabetes) trial. We then review the three main components of a behavioral lifestyle intervention program: behavior therapy, an energy- and fat-restricted diet, and a moderate- to vigorous-intensity physical activity prescription. Research regarding the influence of dietary prescriptions focusing on macronutrient composition, meal replacements, and more novel dietary approaches (such as reducing dietary variety and energy density) on weight loss is examined. Methods to assist with meeting physical activity goals, such as shortening exercise bouts, using a pedometer, and having access to exercise equipment within the home, are reviewed. To assist with improving weight loss outcomes, broadening activity goals to include resistance training and a reduction in sedentary behavior are considered. To increase the accessibility of behavioral lifestyle interventions to treat obesity in the broader population, translation of efficacious interventions such as the DPP, must be undertaken. Translational studies have successfully altered the DPP to reduce treatment intensity and/or used alternative modalities to implement the DPP in primary care, worksite, and church settings; several examples are provided. The use of new methodologies or technologies that provide individualized treatment and real-time feedback, and which may further enhance weight loss in behavioral lifestyle interventions, is also discussed.

Influence of friends on children's physical activity: a review

We examined evidence for friendship influences on children's physical activity (PA) through systematic searches of online databases in May 2012. We identified 106 studies (25 qualitative) published in English since 2000 that analyzed indicators of friendship influences (e.g., communication about PA, friends' PA, and PA with friends) among persons younger than 19 years. Children's PA was positively associated with encouragement from friends (43 of 55 studies indicating a positive relationship), friends' own PA (30/35), and engagement with friends in PA (9/10). These findings are consistent with friends influencing PA, but most studies did not isolate influence from other factors that could explain similarity. Understanding friendship influences in childhood can facilitate the promotion of lifelong healthy habits. PA with friends should be considered in health promotion programs.

Advantage of distance- versus time-based estimates of walking in predicting adiposity

PURPOSE

Physical activity recommendations are defined in terms of time spent being physically active (e.g., 30 min of brisk walking, 5 d · wk(-1)). However, walking volume may be more naturally assessed by distance than by time. Analyses were therefore performed to test whether time or distance provides the best metric for relating walking volume to estimated total and regional adiposity.

METHODS

Linear and logistic regression analyses were used to relate exercise dose to body mass index (BMI), body circumferences, and obesity in a cross-sectional sample of 12,384 female and 3434 male walkers who reported both usual distance walked and time spent walking per week on survey questionnaires. Metabolic equivalent hours per day (MET · h · d(-1), 1 MET = 3.5 mL O2 · kg(-1) · min(-1)) were calculated from the time and pace, or distance and pace, using published compendium values.

RESULTS

Average MET-hours per day walked was 37% greater when calculated from time spent walking versus usual distance in women and was 32% greater in men. Per MET-hours per day, declines in BMI and circumferences (slope ± SE) were nearly twice as great, or greater, for distance- versus time-derived estimates for kilograms per squared meter of BMI (females = -0.58 ± 0.03 vs -0.31 ± 0.02, males = -0.35 ± 0.04 vs -0.15 ± 0.02), centimeter of waist circumference (females = -1.42 ± 0.07 vs -0.72 ± 0.04, males = -0.96 ± 0.10 vs -0.45 ± 0.07), and reductions in the odds for total obesity (odds ratio: females = 0.72 vs 0.84, males = 0.84 vs 0.92) and abdominal obesity (females = 0.74 vs 0.85, males = 0.79 vs 0.91, all comparisons significant).

CONCLUSIONS

Distance walked may provide a better metric of walking volume for epidemiologic obesity research, and better public health targets for weight control, than walking duration. Additional research is required to determine whether these results, derived in a sample that regularly walks for exercise, apply more generally.

Dietary intakes associated with successful weight loss and maintenance during the Weight Loss Maintenance trial

BACKGROUND

Dietary components effective in weight maintenance efforts have not been adequately identified.

OBJECTIVE

To determine the effects of changes in dietary consumption on weight loss and maintenance during the Weight Loss Maintenance clinical trial.

DESIGN

Weight Loss Maintenance was a randomized controlled trial. Successful weight loss participants who completed Phase I of the trial and lost 4 kg were randomized to one of three maintenance intervention arms in Phase II and followed for an additional 30 months.

PARTICIPANTS/SETTING

The multicenter trial was conducted from 2003 through 2007. This substudy included 828 successful weight loss participants.

METHODS

The Block Food Frequency Questionnaire (FFQ) was used to assess nutrient intake levels and food group servings. Carbohydrates, proteins, fats, dietary fiber, fruit/vegetable, and dairy servings were utilized as predictor variables. The FFQ was collected on all participants at study entry (beginning of Phase I). Those randomized to Phase II completed the FFQ at three additional time points: randomization (beginning of Phase II), 12 months, and 30 months.

INTERVENTION

The main intervention focused on long-term maintenance of weight loss using the Dietary Approaches to Hypertension diet. This substudy examined if changes to specific dietary variables were associated with weight loss and maintenance.

STATISTICAL ANALYSES PERFORMED

Linear regression models that adjusted for change in total energy examined the relationship between changes in dietary intake and weight for each time period. Site, age, race, sex, and a race-sex interaction were included as covariates.

RESULTS

Participants who substituted protein for fat lost, on average, 0.33 kg per 6 months during Phase I (P<0.0001) and 0.07 kg per 6 months during Phase II (P<0.0001) per 1% increase in protein. Increased intake of fruits and vegetables was associated with weight loss in Phases I and II: 0.29 kg per 6 months (P<0.0001) and 0.04 kg per 6 months (P=0.0062), respectively, per 1-serving increase. Substitution of carbohydrates for fat and protein for carbohydrates were associated with weight loss during both phases. Increasing dairy intake was associated with significant weight loss during Phase II (-0.17 kg per 6 months per 1-serving increase, P=0.0002), but not during Phase I. Dietary fiber revealed no significant findings.

CONCLUSIONS

Increasing fruits, vegetables, and low-fat dairy may help achieve weight loss and maintenance.

Sedentary behaviors and subsequent health outcomes in adults a systematic review of longitudinal studies, 1996-2011

CONTEXT

To systematically review and provide an informative synthesis of findings from longitudinal studies published since 1996 reporting on relationships between self-reported sedentary behavior and device-based measures of sedentary time with health-related outcomes in adults.

EVIDENCE ACQUISITION

Studies published between 1996 and January 2011 were identified by examining existing literature reviews and by systematic searches in Web of Science, MEDLINE, PubMed, and PsycINFO. English-written articles were selected according to study design, targeted behavior, and health outcome.

EVIDENCE SYNTHESIS

Forty-eight articles met the inclusion criteria; of these, 46 incorporated self-reported measures including total sitting time; TV viewing time only; TV viewing time and other screen-time behaviors; and TV viewing time plus other sedentary behaviors. Findings indicate a consistent relationship of self-reported sedentary behavior with mortality and with weight gain from childhood to the adult years. However, findings were mixed for associations with disease incidence, weight gain during adulthood, and cardiometabolic risk. Of the three studies that used device-based measures of sedentary time, one showed that markers of obesity predicted sedentary time, whereas inconclusive findings have been observed for markers of insulin resistance.

CONCLUSIONS

There is a growing body of evidence that sedentary behavior may be a distinct risk factor, independent of physical activity, for multiple adverse health outcomes in adults. Prospective studies using device-based measures are required to provide a clearer understanding of the impact of sedentary time on health outcomes.

Effect of change in physical activity on body fatness over a 10-y period in the Doetinchem Cohort Study

BACKGROUND

Obesity is related to many adverse health-related outcomes.

OBJECTIVE

We investigated whether changes in physical activity were related to less gain in either body weight or waist circumference (WC).

DESIGN

The association between prospectively assessed physical activity and either body weight or WC was examined in 4944 participants of the Doetinchem Study (men and women aged between 26 and 66 y at baseline). Information on physical activity (derived from a validated physical activity index), body weight, and WC, measured according to standardized procedures, was collected at baseline and at the 5- and 10-y follow-ups.

RESULTS

Random mixed-effects models showed that a single measurement of physical activity was not clearly related to change in body weight and WC over a 5-y period. However, analyses of repeated measures showed that compared with those who maintained their activity level, those who increased their physical activity over a 5-y period had less gain in WC ( minus 0.35 cm; 95% CI: minus 0.65, minus 0.05 cm) and possibly in body weight ( minus 280 g; 95% CI: minus 620, 5 g). Most importantly, these effects were sustained (although not significantly) in the consecutive 5 y for WC ( minus 0.56 cm; 95% CI: minus 108, 0.04 cm) and for body weight ( minus 590 g; 95% CI: minus 1005, minus 130 g), which indicated that physical activity was truly a determinant of body size changes.

CONCLUSIONS

An increase in physical activity was associated with a statistically significant lower gain in body weight and in WC, which was maintained during the following 5 y. These findings support the need for public health programs that promote physical activity.

Bicycle riding, walking, and weight gain in premenopausal women

BACKGROUND

To our knowledge, research has not been conducted on bicycle riding and weight control in comparison with walking. Our objective was to assess the association between bicycle riding and weight control in premenopausal women.

METHODS

This was a 16-year follow-up study of 18,414 women in the Nurses' Health Study II. Weight change between 1989 and 2005 was the primary outcome, and the odds of gaining more than 5% of baseline body weight by 2005 was the secondary outcome.

RESULTS

At baseline, only 39% of participants walked briskly, while only 1.2% bicycled for more than 30 min/d. For a 30-min/d increase in activity between 1989 and 2005, weight gain was significantly less for brisk walking (-1.81 kg; 95% confidence interval [CI], -2.05 to -1.56 kg), bicycling (-1.59 kg; 95% CI, -2.09 to -1.08 kg), and other activities (-1.45 kg; 95% CI, -1.66 to -1.24 kg) but not for slow walking (+0.06 kg; 95% CI, -0.22 to 0.35 kg). Women who reported no bicycling in 1989 and increased to as little as 5 min/d in 2005 gained less weight (-0.74 kg; 95% CI, -1.41 to -0.07 kg; P value for trend, <.01) than those who remained nonbikers. Normal-weight women who bicycled more than 4 h/wk in 2005 had a lower odds of gaining more than 5% of their baseline body weight (odds ratio, 0.74; 95% CI, 0.56 to 0.98) compared with those who reported no bicycling; overweight and obese women had a lower odds at 2 to 3 h/wk (odds ratio, 0.54; 95% CI, 0.34 to 0.86).

CONCLUSIONS

Bicycling, similar to brisk walking, is associated with less weight gain and an inverse dose-response relationship exists, especially among overweight and obese women. Future research should focus on brisk walking and greater time spent bicycling.

Isotemporal substitution paradigm for physical activity epidemiology and weight change

For a fixed amount of time engaged in physical activity, activity choice may affect body weight differently depending partly on other activities' displacement. Typical models used to evaluate effects of physical activity on body weight do not directly address these substitutions. An isotemporal substitution paradigm was developed as a new analytic model to study the time-substitution effects of one activity for another. In 1991-1997, the authors longitudinally examined the associations of discretionary physical activities, with varying activity displacements, with 6-year weight loss maintenance among 4,558 healthy, premenopausal US women who had previously lost >5% of their weight. Results of isotemporal substitution models indicated widely heterogeneous relations with each physical activity type (P < 0.001) depending on the displaced activities. Notably, whereas 30 minutes/day of brisk walking substituted for 30 minutes/day of jogging/running was associated with weight increase (1.57 kg, 95% confidence interval: 0.33, 2.82), brisk walking was associated with lower weight when substituted for slow walking (-1.14 kg, 95% confidence interval: -1.75, -0.53) and with even lower weight when substituted for TV watching. Similar heterogeneous relations with weight change were found for each activity type (TV watching, slow walking, brisk walking, jogging/running) when displaced by other activities across these various models. The isotemporal substitution paradigm may offer new insights for future public health recommendations.