One-year assessment of physical activity level in adult Qatari females: a pedometer-based longitudinal study

Impact of Moderate Physical Activity on Inflammatory Markers and Telomere Length in Sedentary and Moderately Active Individuals with Varied Insulin Sensitivity

Introduction

Physical activity-associated immune response plays a crucial role in the aging process. This study aimed to determine the impact of short-term moderate physical activity on cytokine levels, oxidative stress markers, and telomere length in lean/overweight young subjects.

Methods

Fasting blood samples were collected from 368 participants at Qatar Biobank. Based on their homeostatic model assessment of insulin resistance (HOMA-IR), participants were categorized as insulin sensitive (IS) or insulin resistant (IR). Subsequently, they were divided into four groups: sedentary IS (n = 90), sedentary IR (n = 90), moderately active IS (n = 94), and moderately active IR (n = 94). Moderate physical activity was defined as walking at least two days per week for more than 150 minutes, as determined by physical activity questionnaires. Serum samples were analyzed for circulating inflammatory cytokines (IL-1β, IL-1RA, IL-6, IL-10, IL-22, MCP-1/CCL2, TNF-α), as well as antioxidant enzyme levels (SOD and catalase). Telomere lengths were measured in the respective DNA samples.

Results

Moderately active IR participants exhibited significantly lower SOD activity, while catalase activity did not show significant differences. Moderately active IS participants had higher IL-6 and IL-10 levels compared to sedentary IS participants, with no significant differences observed in the IR counterparts. Telomere length did not significantly differ between the physically active and sedentary groups.

Conclusion

This study highlights the potential anti-inflammatory and anti-oxidative stress effects of moderate physical activity in individuals with insulin sensitivity and insulin resistance. However, no significant changes in telomere length were observed, suggesting a complex relationship between physical activity and the aging process. Further research is needed to fully understand the underlying mechanisms and optimize the balance between anti-inflammation and anti-oxidation through exercise and lifestyle adjustments.

Determinants of Health Care Needs in Relation to Vision Correction among Adolescents in the United Arab Emirates: A Cross-Sectional Study

BACKGROUND

Uncorrected refractive error has been suggested to affect children's development, educational performance, and socialization. Sociodemographic and environmental differences among individuals may impact their accessibility to utilizing appropriate services, impacting their vision-dependent activities.

METHODS

Guided by the population health framework, this retrospective study assessed the prevalence of self-reported vision correction needs and its determinants for a sample of adolescents (n = 6363) from the United Arab Emirates (UAE) aged 13 to 20 years between 2007 to 2009.

RESULTS

The findings suggest a relatively high prevalence of self-reported vision correction needs (26.8%), with among 24.8% males and 31.7% among females. Factors that were significantly associated with vision correction needs included age, biological sex, location of residence (emirate), nationality, parental education and employment level, household financial status, screen time use, visiting an eye specialist in the past year, and daily functional capacity.

CONCLUSION

Reporting the vision correction needs of the adolescent population and identifying its determinants may help identify and resolve modifiable barriers to accessing the appropriate vision care resources. Further research in assessing the type of refractive error, potential genetic and environmental factors, and vision care services in each emirate may help decision-makers set appropriate policies to improve the overall quality of eye health.

Comparing the Metabolic Profiles Associated with Fitness Status between Insulin-Sensitive and Insulin-Resistant Non-Obese Individuals

(1) Background: Young non-obese insulin-resistant (IR) individuals could be at risk of developing metabolic diseases including type 2 diabetes mellitus. The protective effect of physical activity in this apparently healthy group is expected but not well characterized. In this study, clinically relevant metabolic profiles were determined and compared among active and sedentary insulin-sensitive (IS) and IR young non-obese individuals. (2) Methods: Data obtained from Qatar Biobank for 2110 young (20-30 years old) non-obese (BMI ≤ 30) healthy participants were divided into four groups, insulin-sensitive active (ISA, 30.7%), insulin-sensitive sedentary (ISS, 21.4%), insulin-resistant active (IRA, 20%), and insulin-resistant sedentary (IRS, 23.3%), using the homeostatic model assessment of insulin resistance (HOMA-IR) and physical activity questionnaires. The effect of physical activity on 66 clinically relevant biochemical tests was compared among the four groups using linear models. (3) Results: Overall, non-obese IR participants had significantly (p ≤ 0.001) worse vital signs, blood sugar profiles, inflammatory markers, liver function, lipid profiles, and vitamin D levels than their IS counterparts. Physical activity was positively associated with left handgrip (p ≤ 0.01) and levels of creatine kinase (p ≤ 0.001) and creatine kinase-2 (p ≤ 0.001) in both IS and IR subjects. Furthermore, physical activity was positively associated with levels of creatinine (p ≤ 0.01) and total vitamin D (p = 0.006) in the IR group and AST (p = 0.001), folate (p = 0.001), and hematocrit (p = 0.007) in the IS group. Conversely, physical inactivity was negatively associated with the white blood cell count (p = 0.001) and an absolute number of lymphocytes (p = 0.003) in the IR subjects and with triglycerides (p = 0.005) and GGT-2 (p ≤ 0.001) in the IS counterparts. (4) Conclusions: An independent effect of moderate physical activity was observed in non-obese apparently healthy individuals a with different HOMA-IR index. The effect was marked by an improved health profile including higher vitamin D and lower inflammatory markers in IRA compared to IRS, and a higher oxygen carrying capacity and lipid profile in ISA compared to the ISS counterparts.

Adherence and retention to the self-managed community-based Step Into Health program in Qatar (2012-2019)

Purpose

Investigate adherence and retention to the "Step Into Health (SIH)" initiative (www.stepintohealth.qa [website access only available from within the State of Qatar]), a Qatari self-managed community-based health program, from 2012 to 2019.

Methods

Participants (16,711; 16-80 years; 37% females, 34% Qatari) used a pedometer or smartphone application (app) to measure step count. Absolute adherence (ADH) and retention (RET) were calculated, with ADH (%) the ratio between number of days data and SIH enrollment length (RET). Linear Mixed Models identified differences in ADH between RET groups, main effects (i.e., sex, device, age, BMI, nationality) and interaction effects for ADH (RET entered as a covariate).

Results

Average ADH and RET to SIH (irrespective of sex, age, device and BMI) was 50% (±31%), and 16% (±20%), respectively, with ADH differing significantly between RET groups (F = 460.2, p < 0.001). RET (as a covariate) revealed a significant main effect for device (F = 12.00, p < 0.001) and age (F = 4.31, p = 0.001) on ADH observed. There was a significant association between RET and sex (p < 0.001), device (p < 0.001), and age groups 16-25 y (p < 0.001), and 26-35 y (p < 0.001). There were no significant main effects for sex or BMI on ADH, and no interaction effects (p ≥ 0.21) observed.

Conclusions

Follow-up data (e.g., interviews, focus groups, etc.) determining why differences in ADH and RET are observed appears prudent. To convert those that lapsed and/or abandoned SIH/PA into committed long-term PA adherers. This would be a first step to develop targeted public health promotions and initiatives to enhance health outcomes at a population level.

Impact of Seasonality on Physical Activity: A Systematic Review

BACKGROUND

The purpose of this study was to collect and analyze the available scientific evidence of the impact of seasonality on physical activity (PA). PA refers to walking, biking, sports and/or active recreation.

METHODS

The search was performed in the following databases: PubMed, PEDro, Cochrane and Embase. All publications from January 2015 to September 2020 assessing seasonal variations on physical activity development in adults were selected.

RESULTS

A total of 1159 articles were identified, of which 26 fulfilled the selection criteria involving 9300 participants from 18 different countries. The results obtained suggest that seasonality affects PA independently of the countries, pathologies of the participants and the tool to collect PA information.

CONCLUSIONS

PA level varies across the seasons, with higher PA level in summer compared with other seasons, especially in winter. Sedentary behavior follows the opposite trend. Impact of seasonality variations should be considered in clinical research involving PA as a primary outcome as well as in interventions on PA promotion.

A systematic review of interventions to promote physical activity in six Gulf countries

Physical activity (PA) levels are low in Gulf Cooperation Council countries (GCC; Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates). We carried out a systematic review (PROSPERO registration number 131817) to assess the effect of interventions to increase PA levels in this region. We also assessed their effects on anthropometry and cardiovascular risk. A systematic search of six databases (Medline, EMBASE, SPORTDiscus, CINAHL, Cochrane, Web of Science) was performed to identify randomized and non-randomized intervention studies performed in adults and children published between January 1985 and November 2020. We included studies published in English or Arabic, and included PA interventions regardless of setting, delivery, and duration. The primary outcomes were changes in PA duration and intensity. Secondary outcomes included anthropometric measures (e.g., weight, body mass index) and cardiovascular risk profiles (e.g., lipid measures, blood glucose). Two independent reviewers screened studies in accordance with pre-determined criteria, extracted data, assessed risk of bias (Cochrane Risk of Bias 2 and Newcastle Ottawa Scale) and undertook a narrative synthesis. From 13,026 records identified, 14 studies were included. Nine studies focussed exclusively on changing PA behaviour, resulting in statistically significant increases in step count ranging from an additional 757 steps/day (95% confidence interval [CI] 0-1,513) to 3,853 steps/day (95% CI 3,703-4,002). Five identified studies were multi-component lifestyle interventions, targeting people at higher risk (due to obesity or type 2 diabetes). Evidence for increases in PA from multi-component studies was limited, although improvements were seen in outcomes e.g. body weight and blood lipid levels. In conclusion, relatively few studies have focussed on changing PA behaviour, despite the urgent need in the GCC. Limited evidence suggested that pedometer-based programmes encouraging step counting and walking were effective in promoting PA, at least in the short term. Policies to roll out such interventions should be implemented and evaluated.

Ramadan daily intermittent fasting reduces objectively assessed habitual physical activity among adults

BACKGROUND

Muslims around the world practice intermittent fasting during the month of Ramadan each year. We hypothesized that daily physical activity could be reduced among Muslims due to the inability to refuel and rehydrate in the fasting state.

METHODS

A cohort study design among adults registered with national physical activity community program. Data from a pedometer-based community program was used to extract 3 months of daily step counts before, during, and after Ramadan for the past years (2013-2019). A survey was conducted among participants to determine fasting practice and other health and environmental factors.

RESULTS

A total of 209 participants completed the survey and provided valid data on physical activity. During Ramadan, the average steps per day decreased significantly (- 385 ± SE 158) among participants who fasted (n = 151) p = 0.046 and increased (+ 731 ± SE 247) for the non- fasting participants (n = 58) p = 0.010. Fasting participants preferred before sunset (33.8%) or evening (39.7%) for physical activity. Whereas, non-fasting participants preferred early morning (34.5%).

CONCLUSION

Fasting during Ramadan impacts the daily physical activity behavior among Muslims. Interventions should focus on creating awareness of the importance of maintenance of adequate physical activity for adults fasting during Ramadan.

A Qualitative Study of Barriers and Enablers of Physical Activity among Female Emirati University Students

Interventions to promote physical activity participation should reflect social and culturally relevant influences of the target demographic. The aim of this study was to explore perceptions of barriers to and enablers of physical activity participation among female Emirati university students. Five semi-structured focus groups were conducted (n = 25). Participants were asked open-ended questions about benefits, barriers and enablers of physical activity, and recommendations to promote participation. Emergent themes were identified using Nvivo software. Commonly identified benefits included improved health, weight management, improved mood, and stress reduction. The main barriers were low family support, competing time demands from domestic and academic activities, lack of convenient access to women-only facilities, and hot weather. The main enablers and recommendations related to social support from family and friends, accessible and low-cost women-only facilities, and structured supervised sessions. Findings suggest that there are specific social-cultural influences of physical activity among female Emirati university students. Approaches to promote participation could include identifying benefits consistent with family and cultural values, using social media for education, support and modelling, on campus supervised physical activity sessions integrated with the academic timetable, low-cost women-only opportunities in the local residential area, and support for home-based activities.

Obesity and Cardiovascular Risk in the Arab Gulf States

Purpose of Review

Rapid economic growth in the Gulf Cooperation Council (GCC) states over the last half-century has been associated with a rise in obesity and cardiovascular morbidity and mortality. In this review, we shed some light on the factors driving the obesity epidemic, promising interventions to overcome this public health crisis, and challenges precluding a successful public health impact.

Recent Findings

Overweight and obesity rates have nearly tripled in the GCC countries over the past four decades. Cardiovascular morbidity and mortality have been rising in parallel. Several sociodemographic, environmental, and behavioral factors have been correlated with sedentary lifestyle and unhealthy diet habits, and ultimately the rise in overweight and obesity rates. Numerous studies have documented factors unique to the population of the Arab Gulf states, but high-quality data is scarce. Despite the growing awareness of the extent of the problem, several barriers to weight loss and physical activity need to be addressed. A few interventions to combat obesity at different levels have been reported with some promising outcomes. Using the social-ecological model (SEM), we review recently published interventions and discuss some challenges to overcome in order to make progress in fighting the obesity epidemic in the GCC.

Summary

Obesity prevalence has been mounting worldwide, and the Arab Gulf states are no exception. This public health crisis is drawing the attention of policymakers and several stakeholders. However, a lot needs to be done to reduce the burden of obesity and improve cardiovascular risks in the Arab Gulf states.

Correlation between breast cancer and lifestyle within the Gulf Cooperation Council countries: A systematic review

BACKGROUND

In the six Gulf Cooperation Council countries (GCCCs), Bahrain, Saudi Arabia, Kuwait, Oman, Qatar and the United Arab Emirates, breast cancer (BC) is the greatest cause of cancer incidence and mortality. Obesity and physical inactivity are established risk factors for BC globally and appear to be more of a problem in high income countries like the GCCCs.

AIM

To determine whether obesity and physical inactivity are associated with BC incidence in the GCCCs using the United Kingdom as a comparator.

METHODS

This systematic review was carried out according to PRISMA guidelines. A cancer registry and a statistical data search was done to identify the BC incidence over the past two decades and the prevalence of obesity and physical inactivity in the GCCCs. Additionally, a systematic search of the databases, MEDLINE, Web of Science, and PubMed between 1999 and 2019 was performed to determine whether obesity and physical inactivity are risk factors for BC in the GCCCs. All papers were critically appraised according to their research methods and were assessed for quality and risk of bias.

RESULTS

BC was the top malignancy in each GCC country. Women tended to be diagnosed with BC at a younger age than women in the United Kingdom. The greatest 10-year increase in BC incidence was seen in Saudi Arabia (54.2%), approximately seven times the rate of increase seen in the United Kingdom (7.6%). The prevalence of obesity and physical inactivity was greater in all the GCCCs in comparison to the United Kingdom. A total of 155 full studies were reviewed of which 17 were included. Of those, eight looked at the prevalence of obesity and physical inactivity in the Gulf States and nine looked at these as risk factors for BC. Only one study found an association between BC and obesity (odds ratio = 2.29). No studies looked solely at the link between physical inactivity and BC.

CONCLUSION

The prevalence of obesity and physical inactivity was high within the GCCCs, but the majority of the included studies found no positive correlation between obesity or physical inactivity and BC. A high proportion of women in this study were pre-menopausal which could contribute to the negative findings.

Levels of Physical Activity, Obesity and Related Factors in Young Adults Aged 18-30 during 2009-2017

The objective of this study was to analyze the temporal trend of physical activity and body mass index in young adults aged 18–30 in Spain and to ascertain their relationship with sociodemographic and psychosocial variables in the period of 2009–2017. Methods: A descriptive study with a sample of 10,061 young adults aged 18–30 years was performed. The data were obtained from the European Health Survey in Spain in 2009 and 2014 and the National Health Survey in 2011/2012 and 2017. The chi-square test was used for qualitative variables, and multiple linear regression analysis was performed for physical activity. Results: Sedentary levels had decreased in 2017 as compared to 2011/2012 (p < 0.001); smokers were more sedentary than non-smokers (p < 0.001); men were more active than women (p < 0.001); and the year with the highest physical activity was 2014. Body mass index in the total sample increased from 2009 to 2017 (p < 0.01), showing a significant increase in obesity in women (p < 0.05) and no difference in men (p ≥ 0.05). Conclusions: In the period 2011/2012–2017, the sedentary lifestyle of young adults was reduced and physical activity was increased, with men being more active than women.

Physical fitness and physical self-concept of male and female young adults in Qatar

Background

Physical inactivity is high within the Qatari population, particularly within females, and school-based environments, contributing to increased morbidity and mortality. School-based physical activity (PA) outcomes may be mediated by physical self-concept. Low physical self-concept may negatively impact PA engagement, compromising childhood and adolescent physical fitness, which may translate into adulthood. Normative physical fitness data for the Qatari population is unavailable. Stratifying normative physical fitness appears prudent, to not only allow comparisons to be made worldwide, but enable informed decisions for public health policy and future interventions in the Qatari population.

Purpose

To establish the physical fitness of young adults in Qatar, and examine differences between males and females for physical self-concept, and engagement in school-based and extra-curricular PA.

Method

186 (females n = 85) healthy participants [median (minimum—maximum) age: males = 21 (18–26), females = 21 (18–24) y; height: males = 1.74 (1.57–1.99), females = 1.61 (1.46–1.76) m; body mass: males = 71.9 (49.3–145.0), females = 56.8 (35.7–96.4) kg] completed the ALPHA-FIT test battery for adults (one leg stand, figure of eight run, handgrip strength, jump and reach, modified push-up, dynamic sit-up and 2 km walk), physical self-description questionnaire (measuring physical self-concept), and were asked to answer ‘yes’ or ‘no’ to whether they participated in school-based and extra-curricular PA.

Results

Data is reported as effect size; ±90% confidence limit. Males compared to females most likely performed better for dynamic sit-up (2.2; ±0.76), very likely better for the figure of eight run (0.86; ±0.42) and likely better for handgrip strength (2.1; ±0.75). Males likely had higher physical self-concept for coordination (0.78; ±0.37) and endurance (0.66; ±0.27) compared to females. There were no differences for school-based PA (p ≥ 0.78) or for extra-curricular PA for males (p ≥ 0.26) or females (p ≥ 0.21).

Conclusion

The data suggests that the young Qatari adult population has variable, yet generally low, physical fitness traits compared to individuals worldwide, likely due to their low PA. The precise aetiology for this is not well documented, yet such data may be prudent to evidence-inform strategies to improve physical fitness through increased PA (synergistic relationship), given the strong association between physical activity/fitness and morbidity/mortality.

Effect of a pedometer-based walking challenge on increasing physical activity levels amongst hospital workers

Background

More than 50% of Qatari adults are physically inactive. The workplace is an excellent environment to implement cost-effective, efficient behavioural physical activity (PA) interventions to increase PA. This study evaluated whether a pedometer-based walking challenge would increase PA levels amongst hospital workers.

Methods

A pedometer-based workplace walking intervention was implemented in April–August 2017. Amongst 800 recruited full-time hospital workers, a cross-sectional sample of 212 workers completed the online questionnaires Quality of Life Questionnaire, International Physical Activity Questionnaire (IPAQ), and Workforce Sitting Questionnaire. A sub-sample of participants (n = 54) wore a pedometer for 3 months. They recorded their daily step count through an online web platform linked to the pedometer. Another cross-sectional sample (n = 194) in the same target population completed online questionnaires at post intervention.

Results

The IPAQ assessed physical activity at post-intervention was higher compared to pre-intervention. In a sub-sample (n = 54) that provided pedometer data, workers’ step count during intervention was significantly higher (9270) from pre-intervention (7890) (p = 0.048).

Conclusions

Although self-reported PA was higher post-intervention, the subsample showed objectively assessed physical activity did not exceed the threshold recommended for optimal health. Therefore, encouraging participation and maintaining motivation amongst workers in a work-based PA programme is challenging.

Breaking up prolonged sitting with moderate-intensity walking improves attention and executive function in Qatari females

Background

Cultural, environmental and logistical factors promote a sedentary lifestyle within Qatar, particularly for females. Sedentary behaviour is acutely associated with poor cognitive function and fatigue, and chronically may be implicated with cognitive decline (i.e. Alzheimer’s disease).

Purpose

To examine the effects of breaking up sitting with short-duration frequent walking bouts on cognitive function and fatigue in Qatari females.

Method

Eleven sedentary (sitting ≥7 h/day) females completed three visits; the first being familiarisation. In a cross-over randomised manner, experimental visits two and three were identical, except participants either remained seated for 5-h (SIT) or interrupted their sitting every 30-min with a 3-min moderate-intensity walk (WALK) on a motorised treadmill. The Computerised Mental Performance Assessment System (COMPASS) assessed cognition at baseline (-15-min), and then at 2.5-h and 5-h into the experimental conditions. Specific COMPASS tasks employed were; serial-3 subtractions (2-min), serial-7 subtractions (2-min), simple reaction time (RT; 50 stimuli), rapid visual information processing [RVIP (5-min)], choice reaction time (CRT; 50 stimuli), and Stroop (60 stimuli); and a visual analogue scale for fatigue (VAS-F) was completed at the same time intervals.

Results

There was a significant condition effect for CRT (f = 26.7, p = 0.007). On average CRT was 101 s (95% CI = -47 to -156 s) quicker in WALK compared to SIT. There was a significant time effect for CRT (f = 15.5, p = 0.01). On average CRT was 134 s slower at 5-h compared to baseline (p = 0.006; 95% CI = -64 to -203 s), and 114 s slower at 5-h compared to 2.5-h (p = 0.01; 95% CI = -44 to -183 s). There was a significant interaction effect for RT in the Stroop incongruent task (f = 10.0, p = 0.03). On average RT was 210 s quicker at 2.5-h in WALK compared to SIT (p = 0.01; 95% CI = -76 to -346 s).

Conclusion

Breaking up prolonged sitting with moderate-intensity walking offers an ecologically valid intervention to enhance some aspects of cognitive function, whilst not affecting fatigue in sedentary Qatari females. Whilst these findings are promising, the long-term effects of breaking up sitting on cognitive function requires testing before population level recommendations can be made.

Postprandial Insulin and Triglyceride Concentrations Are Suppressed in Response to Breaking Up Prolonged Sitting in Qatari Females

Background: Cultural, environmental and logistical factors challenge the Qatari population, particularly females, to engage in physical activity, and there is a high prevalence of diabetes in this population. Sedentary behavior is associated with increased cardiometabolic disease risk and early mortality and breaking up sitting can attenuate postprandial cardiometabolic risk markers. However, no studies have evaluated the cardiometabolic response to breaking up sitting in a Qatari population. Purpose: To examine the effects of breaking up sitting with moderate-intensity walking breaks on cardiometabolic disease markers in Qatari females. Methods: Eleven sedentary (sitting ≥ 7 h/day) females completed two experimental conditions in a cross-over randomized design. The two conditions were identical, except participants either remained seated for 5-h (SIT), or interrupted their sitting every 30-min with a 3-min walk (WALK) on a motorized treadmill (rating of perceived exertion 12-14). A fasting venous blood sample was obtained at baseline (-10-min) followed by samples at 0.5-, 1-, 2-, 3-, 3.5-, 4-, and 5-h. Postprandial cardiometabolic variables (insulin, glucose, triglycerides) were calculated as derivatives of total area under the curve [AUC; total (tAUC), net incremental (iAUC) and positive AUC]. Results: Data is reported as effect size; ±90% confidence limit. There was a most likely "moderate" lower tAUC (-0.92 ± 0.26), iAUC (-0.96 ± 0.33), and positive AUC (-0.96 ± 0.33) for insulin in WALK compared to SIT. Additionally, there was a most likely "moderate" lower tAUC (-0.63 ± 0.37), iAUC (-0.91 ± 0.49), and positive AUC (-0.91 ± 0.49) for triglycerides in WALK compared to SIT. Glucose did not differ between conditions. Conclusion: Breaking up prolonged sitting with moderate-intensity walking offers a culturally compatible intervention to acutely improve cardiometabolic risk markers in sedentary Qatari females. Whilst the data offers promise, the long-term chronic effects of breaking up sitting in Qatari adults requires investigation before population level and/or policy recommendations can be made.

Overweight and obesity among adults in the Gulf States: A systematic literature review of correlates of weight, weight-related behaviours, and interventions

Obesity has increased to an epidemic level in the Gulf States. This systematic review is the first to explore the scientific evidence on correlates and interventions for overweight (body mass index [BMI] ≥ 25) or weight-related behaviours in the region. A systematic search of peer-reviewed articles was conducted using PubMed and PsycINFO. Ninety-one studies were eligible for this review including 84 correlate studies and seven intervention studies. Correlate studies of overweight focused on sociodemographic factors, physical activity, and dietary habits. Low physical activity, sedentary behaviour, and unhealthy dietary habits were associated with overweight. The most-reported sociodemographic correlates of overweight were increased age, being married, low education, urban residence, and unemployment. Correlate studies of physical activity and dietary behaviours mostly focused on sociodemographic variables. Being female and increased age (the latter less consistently) were associated with low physical activity. Interventions were very heterogeneous with respect to the target group, intensity, and behavioural strategies used. The effectiveness of interventions was difficult to evaluate because of the chosen study design or outcome measure, the small sample size, or high attrition rate. Few studies have investigated sociocognitive and environmental determinants of weight-related behaviours. Such information is crucial to developing health promotion initiatives that target those weight-related behaviours.