Sleep a total of 3495 children were included

Sleep plays a vital role in the growth and overall health in children alongside diet and physical activity. However, with modern day stressors and a rise in the exposure and ease in access of technology, sleep deprivation is becoming more prevalent in both adults and children. Previous research suggests an association between short sleep duration and childhood obesity (Chen X, Beydoun MA, Wang Y, 2008, cited in Shi, Z et al, 2012), although some research suggests gender differences, whereby the risk of being overweight was more prevalent in Australian boys than girls (Eisenmann JC, Ekkekakis P, Holmes M, 2006, cited in Shi, Z et al, 2012).  The following article by Shi et al (2010) explores how sleep deprivation poses as a potential risk factor contributing to childhood obesity, whereby the main objective of the article was to assess how underlying potential physiological and pathological mechanisms from sleep deprivation such as physical activity, dietary habits and insulin sensitivity contribute to obesity among children aged 5-15 years. Data was collected via the South Australian Monitoring and Surveillance System. Between January 2004 to December 2008 participants were selected randomly each month from a list of telephone numbers in the Electronic White Pages. In total 3505 structured telephone interviews were assessed with parents of children aged 5-15 years old. Children who had a sleep duration of <4 or >14 hours per day were excluded from the analysis. Therefore, a total of 3495 children were included within the analysis whereby all the participants had given informed consent. Sleep duration was assessed with close ended questions on the topics of BMI, Fruit and Vegetable intake as well as Physical activity. The key findings of the article found that the prevalence of obesity was 7.7% among the 3495 children. 23.9% of the participants had a sleep duration of less than 9 hours, while 51% reported sleeping 10 hours or more every day, however short sleep duration was highly associated with age as well as the prevalence of obesity. A strong association between short sleep duration (less than 9 hours) and obesity was found to correlate positively between children aged 5-10 years. On the other hand, no such association was found among children aged 13-15 years. Furthermore, a relationship between short sleep duration and a decline in physical activity and fruit and vegetable intake was established. Other findings suggested that the associations between short sleep duration and obesity was stronger in males however these differences were not significant.In conclusion, the study supports the notion that short sleep duration contributes to obesity among children from South Australia. Alongside this, short sleep duration contributed to mechanisms that influenced weight gain such as low levels of physical activities, decreased levels of Leptin, Glucose intolerance, Insulin sensitivity and an increased level of ghrelin. An implication of the article was that the topic area of sleep duration and its effects in relation to childhood obesity is a relatively new area that has not had much previous research, however the research conducted is relevant. On the other hand, the research did address the aims of short sleep duration acting as a contributor to childhood obesity. Therefore, further research must be conducted to further support and strengthen the validity of the research. The article had hypothesised that there was an association between short sleep duration and obesity in children, as well as a positive correlation between short sleep duration and a decline in physical activity. Both these hypotheses were supported within the results of the study. There has been an increase in the number of population studies on sleep and childhood obesity which has shaped and impacted this research article. Previous research also supports the results obtained that a potential link of causality was found between short sleep duration and childhood weight gain (Sekine, M. et al, 2002). Further research must be conducted to explain why after the age of 10 there is no association between sleep duration and weight gain.  Some limitations regarding the results of the article are that the dietary patterns were not measured, this is an important contributing mechanism to childhood obesity as previous studies depict how short sleep is linked to incresed fat intake (Shi Z, McEvoy M, Luu J, Attia J, 2008, cited in Shi Z, 2010).Furthermore, most studies within this topic area are outdated or have not been investigated enough as it is a relatively new area. One study was based on data collected in 1985 and focused more on the increased risk of being overweight among Australian boys (Eisenmann JC, Ekkekakis P, Holmes M, 2006, cited in Shi Z et al, 2010). Another study conducted between 1985-2004 portrayed the prevalence of obesity and decline in sleep among children in Australia between 10-15 years of age (Dollman J, Ridley K, Olds T, Lowe E, 2007, cited by Shi Z et al, 2010). This therefore suggests that much of the research conducted is outdated implying updated and further research is required to expand our understanding on topic area. The methodology used within the article were structured interviews, whereby a set of pre-determined questions were implicated, however due to this the results may have been influenced. The researcher could have purposely chosen questions to gain a desired response. Therefore, the article suffers from researcher bias and the results cannot be entirely generalised or representative to the target population. However, the presence of the interviewer could be positive as they are present to explain the questions  avoiding misinterpretation, furthermore the interviewer was highly skilled and trained in the topic area. On the contrary the researcher could have influenced the results through being subjective during the interview. A strength of structured interviews is that they are easy to replicate as the set of questions are fixed. In addition to this, the results gained will be quantitative thus making it easier to quantify and test for reliability. More over, structured interviews are quick to conduct as the questions have been pre-determined. This suggests that the interview could take place in a short amount of time. However in comparison to questionnaires interviews are more time consuming and smaller samples are used. Structured interviews are also not flexible as the questions are predetermined, additionally the answers received from structured interviews lack detail as closed questions are asked therefore gaining quantitative data. Over all the sample size used within the analysis was  large adding validity to the study, however, the sample was not entirely representative towards  children globally as it was taken from the South of Australia. Social class, race and ethnicity was not considered within the sample suggesting the sample was not entirely representative.Moreover the sample was limited to people who had telephones and were in the electronic white pages.  On the other hand the sample did make appropriate and effective use of all the data collected.Informed consent was obtained as mothers participated on behalf of their children suggesting the study was highly ethical, however the study could have possibly suffered from demand characteristics and social desirability, as the mothers may have felt a pressure to be portrayed in a certain way. The study was conducted over an extended period of time suggesting it was a longitudinal study. A strength of this is that the researcher gets to know the respondents well, building a strong rapport implying participants are more likely to trust somebody they know. In contrast to this it is a time consuming process and is rather demanding for both the researcher and participants. Moreover, the data suffers from sample attrition, where people may drop out over time. Chi square tests were used to compare differences within the categorical variables, this was advantageous towards the research as the test could establish associations between the variables of short sleep duration and childhood obesity. Furthermore, differences were identified between both expected and observed values. However, the data collected within Chi square tests must be numerical, therefore the data obtained was quantitative, whereby disadvantages include the data lacking rich detail which would be found within qualitative data. On the other hand, the data collected from quantitative research is more representative due to larger sample sizes being used. Also it is easier to establish patterns alongside the cause and effect due to the simplicity of the results. An implication for future research is the economy, where detecting that short sleep duration could influence childhood obesity would equip us with the knowledge to educate parents, on the importance of making sure that children gain the national recommended sleep. Ultimately this would help towards the economy as it would save costs among the NHS that are associated with being overweight such as diabetes, heart disease, cancer and so forth. Furthermore, parents who take time off work due to the sickness of their child would be able to return conclusively reducing the burden on the employer, NHS and taxpayer.To conclude, the research design could be improved by using semi structured interviews as the data collected will be rich in detail. Alongside this  electronic questionnaires could be incorporated  to reach a larger scale of participants globally while also making the experiment both cost and time efficient.