What do we want to know?
The systematic map aimed to review the scope of the quantitative research literature on the relationship between obesity and sedentary behaviour in young people aged 6-16 in order to:
- Identify where there appeared to be gaps in the literature;
- Assess whether there was sufficient research to warrant an in-depth review and synthesis.
Who wants to know and why?
In January 2008, in the report ‘Healthy Weight, Healthy Lives’, the Government recognized obesity reduction as a national priority and set out an aim to reverse the current obesity trend. It has been argued that a better understanding of the dynamics of weight gain amongst young people is required to design effective policy solutions. Increasing levels of sedentary behaviour such as television viewing have been hypothesized as having some relation to the increase in weight being found amongst young people.
What did we find?
- 326 relevant studies were identified. The majority of studies were conducted in the United States, followed by Canada and Australia. Only 15 were undertaken in the UK. Studies covered both Primary and Secondary school age ranges and most covered both boys and girls.
- Studies used a variety of different measures of sedentary behaviour. The most frequent measure was time spent in TV, film and video viewing or a proxy for this, such as TV in the bedroom or number of TVs in the house. This was followed by computer use/playing computer games/owning a computer and playing video games. Most studies use Body Mass Index (BMI) as an indicator of obesity.
- Most studies explored the relationship between obesity and sedentary behaviour. 197 studies attempted to assess the effect of sedentary behaviour on obesity, 65 studies aimed to assess the effect of obesity on sedentary behaviour, and eight studies assessed both. In addition there were 41 intervention studies that attempted to manipulate sedentary behaviour and assess its effect on obesity.
It is our judgement that there is probably sufficient evidence to address two specific in-depth review questions:
- What are the factors/mechanisms that link sedentary behaviour to obesity in children aged 6-16?
- What are the most effective interventions to reduce obesity through reduction of sedentary behaviour in children aged 6-16?
Further primary research may also be needed as comparatively few of the studies identified were carried out in the UK.
What are the implications?
This systematic map of the quantitative research literature on the relationship between obesity and sedentary behaviour in young people aged 6-16 aimed to identify literature on the factors that link sedentary behaviour with obesity as well as interventions that influence obesity/sedentary behaviour. This map cannot provide answers about the relationship between obesity and sedentary behaviour but rather indicates potentially fruitful directions for future research. Implications for primary and secondary research are discussed.
How did we get these results?
A thorough search strategy was developed and all of the main social science databases were searched for relevant research. In addition, ‘handsearching’ of bibliographies and searches of the so-called ‘grey’ literature was undertaken. The initial searches identified 9,769 papers. After removing duplicate papers and applying the inclusion/exclusion criterion, 326 full text studies on the topic were identified. Limited coding was undertaken to enable limited description of studies.
The EPPI-Centre reference number for this report is 1706.
This report should be cited as:
Kalra N, Newman M (2009) A systematic map of the research on the relationship between obesity and sedentary behaviour in young people. Technical report. In: Research Evidence in Education Library. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London.