The problem just keeps getting bigger

Obesity is a major contributor to morbidity and mortality, a considerable economic burden to society, and a non-age-specific condition of increasing global prevalence.1 It remains an important topic of debate as health professionals and policymakers grapple with how best to manage this condition.2 The aetiology of obesity is complex, but central to the network of interacting factors is individual energy imbalance — energy intake (food) greater than energy expended (basal metabolic rate plus physical activity) — over an extended period.3 Thus both eating and activity behaviours are important foci in maintaining a healthy weight.

Environmental and policy change to provide more supportive environments that promote healthy choices as easier choices, and a coordinated approach involving multiple sectors and agencies2 are essential for the multilevel action required.1 Such action aims to prevent development of overweight, prevent increased levels of overweight and manage those who are already overweight or obese (in Australia, 55% women, 68% men and 25% children and adolescents4) to prevent associated morbidity and mortality.

Worldwide progress in the area of government leadership and policy change has been slow.5 The development of behaviour guidelines, such as physical activity guidelines for preschoolers as discussed in the article by Skouteris and colleagues in this issue of the Journal,6 are important but are a very small component of a complex system.2 Interestingly, Australia is one of only four countries worldwide to specifically define daily physical activity targets for preschoolers.6 Further, only two of the four sets of guidelines mention sedentary activity and only the Australian guidelines set a limit: less than one hour a day of screen time for 2–5 year olds and no screen time for children aged less than 2 years.

Skouteris and colleagues acknowledge the limitations of these guidelines, while identifying their importance with respect to interventions for managing weight. However, as preventing and managing overweight at the individual level is a matter of energy balance, adhering to these activity guidelines (or healthy eating guidelines) does not ensure that an individual will maintain a healthy weight. Nevertheless, the guidelines provide a platform to promote the importance of physical activity and a benchmark against which to assess population activity levels. The limited data on physical activity levels of preschoolers in Australia present variable results but generally show that preschoolers fall well short of meeting the Australian guidelines.6 Combined with dietary data on intake of energy-rich, nutrient-poor foods in preschoolers,7 it is not surprising that up to a quarter are overweight.

Importantly, physical activity and limited sedentariness have much broader health implications than maintaining a healthy weight, as argued by Green and Maiorana8 in this issue of the Journal, and these benefits are relevant to all ages. Exercise should be a regular component of every individual’s daily activities. Despite the limitations of the activity guidelines for preschoolers their publication alerts those interacting with young children to the importance of daily activity. Carers have a responsibility to provide opportunities and to encourage preschoolers to be active in a variety of ways and as often as possible in their waking hours.

Limited data from South Australia suggest that early childhood care facilities are likely to have a healthy eating policy but unlikely to have an activity policy.9 Thus there is a clear need for development in this area. For most preschool children, the home environment is the major determinant of their eating and activity; therefore, promotion of these guidelines to parents is an important implementation strategy. Health professionals, including medical practitioners who interact with parents and their children, have a role in this promotion. Further, early identification of eating and activity behaviours that increase the risk of positive energy balance are important components, at the individual level, of obesity prevention. Given parents’ overall lack of identification and awareness of unhealthy weight in their children, regular growth assessment in children, a key health outcome, is also an important obesity prevention strategy.10

While national and state-based programs are important initiatives, broader environmental change that encompasses urban design and infrastructure (eg, safe streets, access to parks and pools in less affluent areas) is an essential element of the solution. Meanwhile, parents and carers can access excellent healthy eating and activity resources from a number of websites, such as the national Get Up and Grow initiative (http://www.health.gov.au/internet/main/publishing.nsf/Content/phd-early-childhood-nutrition-resources), the Raising Children Network (http://raisingchildren.net.au), and the South Australian Healthy Eating and Physical Activity in the Early Years project (http://www.earlyyears.sa.edu.au/a8_publish/modules/publish/content.asp?id=28304&navgrp=3249).

Obesity prevention and management is complex and requires complex solutions, but physical activity is an important component for all ages and, like healthy eating, has much broader health outcomes than weight management alone. Health professionals can contribute to the solution by advocating for policy and environmental change. At the individual level, they should promote the importance of healthy eating and activity, and an awareness of healthy growth, particularly in young children.