Exercise as it relates to Disease/Relationship between Physical inactivity and adiposity in Prepubescent Boys

This is an critical appraisal on the journal article 'Relationship between Physical inactivity and adiposity in Prepubescent Boys.

What is the background to the research?
One of the biggest concerns facing the 21st century is the epidemic of overweight or obese children. The epidemic is worldwide with there being estimated to be 42 million overweight children globally and one third of the children in Australia alone being obese or overweight. These children are more likely to stay overweight in adulthood and are at high risk of developing non-communicable diseases such as diabetes or cardiovascular diseases. Obesity contributes to 3 million preventable deaths globally per year, which is why it is essential that children are taught good behaviours from an early age. Obesity leads to a considerable economic burden being placed on the country. In 2008 the total annual cost of obesity in Australia was estimated to be $58 billion. The reason for these significant increases in childhood obesity can be attributed to the increase in portions sizes, high fat sugary foods, lack of physical activity, overweight parents and an increase in sedentary behaviour. The increase in sedentary behaviour is largely due to an increase in Television or computer time that children have per day. It was found that over 50 per cent of youth were not meeting the AAP (American Academy of Paediatrics) guidelines which recommend a limit of 2 hours or less of screen time per day but instead exceeding it. The epidemic of obese and overweight children provides avenues for research into reducing sedentary behaviours to combat the problem faced.

Where is the research from?
Maffeis, Zaffanello and Schutz from the Department of Pediatrics conducted this research through the University of Verona (Italy), Institute of Physiology and University of Lausanne (Switzerland).

What Kind of Research was it?
This is a cross sectional study which determined whether adiposity in a group of 9 year old boys was related to physical inactivity. Data was obtained through direct measures of heart rate and total energy expenditures.

What did the research involve?
A sample of 28 prepubertal boys with different fat-mass measurements were selected with a BMI range of 12.9 to 30.9 kg/m². Data was collected for each of the boys using the following methods:

What were the basic results?
Maffeis, Zaffanello and Schutz found a large range in the data obtained with daily time devoted to sedentary activities 290 ± 155 minutes and the time devoted to non-sedentary activities 534 ± 150 minutes. There was also a large range in total energy expenditure (TEE) per day 9388 ± 1356. The results of this study show that there was a positive relationship between the level of physical inactivity and the level of adiposity in pre-pubertal boys in free-living conditions.

How did the researchers interpret the results?
The researchers interpreted the results as supporting the hypothesis that physical inactivity may contribute to adiposity in children. However they were not able to find a link between TEE and adiposity in pre-pubertal boys, which could be attributed for the fact that the boys in this study were in a dynamic phase of weight gain. The fact that this was not considered when measuring TEE is a possible flaw in the research. This was evident in the fact that TEE was found to be similar per fat mass unit even in boys with different adiposity levels. The fact that direct measures were taken throughout the study meant that bias could be eliminated. However more longitudinal studies need to be conducted to establish whether physical activity in obese children is a direct or casual factor of increased fat.

What conclusions should be taken away from this research?
The main conclusion drawn from this study is that there is a correlation between overweight or obese children and sedentary behaviour. Various other studies have supported this finding. Children are expending less energy today due to an increase in sedentary behaviour, which in turn leads to an increase in obesity rates. The reduction in sedentary activity particularly television viewing in children would be an effective treatment to reduce childhood obesity. Sedentary behaviour is a major contributor to morbidity and mortality rates in overweight individuals. To help prevent and treat childhood obesity the need for the reduction in sedentary behaviour is paramount.

What are the implications of this research?
This research demonstrates that there is a link between sedentary behaviour and fat mass in children. This implies that there is a need for an intervention that promotes behavioural change in reducing sedentary behaviour in children. This would be a significant factor that would help reduce childhood obesity and adulthood obesity later in life.