Definition
Obesity is defined as having excess body fat accumulated to the extent that it may be detrimental to health, leading to increased health problems and reduced life expectancy. Obesity is measured using Body Mass Index (BMI), which is a function of the body weight and height. According to World Health Organization (WHO) recommendations, an adult whose BMI is below 18.5 kg/m2 is underweight; 18.5-24.9kg/m2 has healthy weight, 24.9-29.9kg/m2 is overweight while 30 kg/m2 and above is obese.
For children, BMI is categorized into percentiles, using gender and age-specific charts. A child with a BMI below the 5th percentile is underweight, between 5th and 15th percentile is probably at the risk of underweight; between 15th and 85th percentile is healthy weight; between 85th and 95th percentile is overweight while a child whose BMI is above 95th percentile is obese.
Predisposing factors
a. Eating habits
Childhood obesity is increasing globally at an alarming rate. This is partly due to changing dietary patterns as well as lifestyle habits. Generally there is an increased consumption of calorie-rich foods and drinks instead of healthy foods like whole meal grains, fruits and vegetables. This has been contributed to in part by upsurge of fast-food eateries and their promotion through media commercials. In the developing countries, especially in Africa, eating patterns also change following rural-urban migration, which happens due to better job opportunities and schools for children in the urban areas. In this process family diets change from the traditional natural, healthier farm produce to commercial, more refined options available in the supermarkets.
b. Sedentary lifestyle
Together with the dietary changes, there are lifestyle changes as well. The urbanite lives a relatively sedentary life compared to the rural child. the latter, for example, walks and runs to school while the child schooling in the city is dropped to and picked from school or rides to and fro on public transport. To add onto that, globally children are spending more time on sedentary recreation, like watching television or playing video games than playing outside. The time spent in front of the television is also spent consuming unhealthy snacks and drinks.
These two factors are the major key players in the increasing trend of childhood obesity, but a few others also play a role.
c. Socioeconomic factors
Whereas in some developed countries obesity tends to occur more commonly in the lower socioeconomic class, in developing countries-especially Africa, it is considered a problem of the rich, who actually do not consider it as such, but consider it a status symbol. It becomes an uphill task in this case to convince these people that their children are obese and that something has to be done about it.
d. Genetics
Inheritance may also play a role in some cases of obesity, however, this is further influenced by family dietary practices and lifestyle.