Asia region showed the lowest prevalence of insufficient PA (74%), whereas the highest were observed in the Asian Pacific region, the Eastern Mediterranean region, and the Sub‐Saharan African region (92%, 89%, and 85%, respectively). Globally, adolescent girls were generally less active than adolescent boys, with 85% vs. 78% not meeting WHO recommendations. Furthermore, the prevalence of inactivity was highest in the upper‐middle‐income countries and lowest in the lower‐middle‐income countries, for all age groups.
The high prevalence of physical inactivity globally is attributed to insufficient participation in PA during leisure time and an increase in sedentary behavior during occupational, domestic, and transportation activities. Research into the correlates (i.e., factors associated with activity) or determinants (i.e., those with a causal relationship) has proliferated in the past two decades, mostly focused on individual‐level factors in high‐income countries, and has shown that age, sex, health status, self‐esteem, and motivation are associated with PA. However, recently developed ecological models suggest that various components of the social and physical environment, e.g., urban planning, transportation systems, parks, and trails, significantly affect our daily physical activity.
Modern urbanization has resulted in environmental changes that are thought to discourage participation in PA in all domains, such as an increase in violence, high‐density traffic, and air pollution, as well as a lack of parks, sidewalks, and sports/recreation facilities. The aforementioned factors might explain, at least in part, the lower prevalence of physical inactivity in low‐ and lower‐middle‐income countries, due to maintenance of work and transport‐related PA, and the higher prevalence observed in higher‐income countries, where the increased automation of life creates opportunities for sedentariness.
Inactive adults have 20–30% increased risk of all‐cause mortality, compared to those who engage in at least 150 minutes of moderate‐intensity PA per week (Figure 3.3). A study by Lee et al. in 2012 revealed that physical inactivity can be deemed responsible for 6% of the burden of disease from coronary heart disease, 7% of T2DM, 10% of breast cancer, and 10% of colon cancer. Moreover, it was estimated that physical inactivity causes 9% of premature mortality, or more than 5.3 million of the 57 million deaths that occurred worldwide in 2008; if inactivity were decreased by 10% or 25%, more than 533,000 and 1.3 million deaths could be averted every year, respectively. Interestingly, using life‐table analysis, Lee et al. also showed that the elimination of physical inactivity would increase the life expectancy of the world's population by 0.68 years (Figure 3.4).
FIGURE 3.1 Trends in insufficient physical activity for three income groups from 2001 to 2016. The shaded areas show 95% uncertainty intervals.
Source: Reprinted with permission from Guthold et al. (2018).
Key Point
Inactive adults have 20–30% increased risk of all-cause mortality.
Given the severe public health effects of physical inactivity, efficient multisectoral and multidisciplinary policies need to be implemented, in order to achieve an increase in PA in the population worldwide. Under this scope, in 2013, WHO member states agreed to a target of reducing sedentariness by 10% by 2025 in the “Global Action Plan for the Prevention and Control of NCDs 2013–2020.” The WHO suggested four policy actions for achieving this PA goal:
1 Adopt and implement national guidelines on PA for health.
2 Develop policy measures to promote PA through activities of daily living, including active transport, recreation, leisure, and sport.
3 Create and preserve built and natural environments that support PA in schools, universities, workplaces, clinics, and hospitals, and in the wider community.FIGURE 3.2 (a) Country prevalence of insufficient physical activity in women in 2016. (b) Country prevalence of insufficient physical activity in men in 2016.Source: Reprinted with permission from Guthold et al. (2018).
4 Implement evidence‐informed public campaigns through mass media, social media, and at the community level to inform and motivate adults and young people to be more physically active.
The WHO has published guidelines to assist the member states and other stakeholders in the development and implementation of national PA plans and to provide guidance on policy options for effective promotion of PA at the national level. Most European and American countries have indeed integrated the promotion of PA at least to some extent in their national health and other policies. However, there is a need to continue updating the policies, both methodologically and substantially, in order to combat the current global sedentariness epidemic and promote the adoption of PA guidelines.
Key Point
Most European and American countries have integrated the promotion of PA at least to some extent in their national health and other policies.
Unhealthy Weight
Unhealthy weight is a well‐documented risk factor for NCDs development, even in the absence of other major risk factors. Maintaining a healthy weight and refraining from smoking increases the years spent in good health, in both men and women. For obese men, the number of years spent in good health are decreased by 4.6 years, relative to men living a healthy life. For men who smoke, the number of years spent in good health are decreased by 7.8 years. The respective decreases for women are 4.5 and 6.0 years, for obese and smokers, respectively.
FIGURE 3.3 Total annual number of deaths by risk factor.
Source: Reprinted with permission from the Global Burden of Disease Collaborative Network. Global Burden of Disease Study 2017. Institute for Health Metrics and Evaluation (IHME) (2018).
FIGURE 3.4 Map of the world showing estimated gains in life expectancy with elimination of physical inactivity.
Source: Reprinted with permission from Lee et al. (2012).
In addition, in a meta‐analysis of 230 cohort studies (207 publications), overweight and obesity were associated with increased risk of all‐cause mortality, with the lowest risk observed at BMI 23–24 kg/m2 among never smokers, 22–23 kg/m2 among healthy never smokers, and 20–22 kg/m2 with longer durations of follow‐up.
As is usually the case, not all studies agree; data from the Dutch Burden of Disease study suggest that elimination of smoking or obesity does not result in absolute compression of morbidity but slightly increases the part of life lived
