RESUMEN
REVIEW OBJECTIVE: The objective of this review is to synthesise the best available evidence on the effectiveness of web-based programs on the reduction of childhood obesity in school age children. BACKGROUND: Childhood obesity is one of the most serious public health challenges of the 21st century. The problem is global and is steadily affecting many low- and middle-income countries, particularly in urban settings.[1] The prevalence has increased at an alarming rate globally.[2] The International Association for the Study of Obesity; estimates that up to 200 million school aged children are either overweight or obese, of those 40-50 million are classified as obese. Obesity has negative health impact in childhood, as well as in the long term.Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health. Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity. It is defined as a person's weight in kilograms divided by the square of his/her height in meters (kg/m). The World Health Organization defines overweight as BMI greater than or equal to 25 and BMI greater than or equal to 30 as obesity. Children two years of age or older with a BMI between the 85 and 94 percentile on age-growth charts are considered overweight; children with a BMI greater than the 95 percentile are considered obese. BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages worldwide. Measures of central obesity such as the waist:hip ratio and waist circumference can provide more robust indices of overall obesity-related health risk than BMI alone. A BMI z-score is a quantitative measure of the deviation of a specific BMI percentile from the mean of that population. A positive z-score indicates a child is heavier than the mean and a negative z-score indicates a child is lighter than the mean. Thus, a z-score compares the BMI of a given child to the BMI distribution for a population of children of the same age and sex.The incidence of obesity has more than doubled since 1980. Overweight and obesity now ranks as the fifth leading global risk for mortality. Sixty-five percent of the world's population lives in countries where childhood overweight and obesity kills more people than being underweight. In addition, 44% of the diabetes burden, 23% of the ischemic heart disease burden, and between 7% and 41% of certain cancer burdens are attributable to overweight and obesity.Childhood obesity continues to be a significant health problem in the United States. There has been a rapid rise in obesity among the school-age population despite efforts made by Healthy People 2010 in promoting weight management and physical activity. These on-going efforts have been extended to be part of the goals for Healthy People 2020. The United States Centers for Disease Control and Prevention calculated that approximately 17% children between the ages of two to nineteen years of age were at or above the 97 percentile for being obese. These figures are more than three times the anticipated 5% set in the Healthy People 2010 report.Overweight and obese children are likely to stay obese into adulthood and are more likely to develop non-communicable diseases like diabetes and cardiovascular diseases at a younger age. In addition to a higher risk of obesity and non-communicable diseases later in life, affected children experience adverse outcomes such as breathing difficulties, increased risk of fractures, hypertension, and early markers of cardiovascular disease, different forms of cancers, insulin resistance, and psychological effects. Childhood obesity is associated with a higher chance of obesity, premature death, and disability in adulthood. If a child is overweight before eight years of age, obesity in adulthood is likely to be more severe.Child and adolescent obesity is also associated with increased risk of emotional problems. Teens with weight problems tend to have much lower self-esteem and are less popular with their peers. Depression, anxiety, and obsessive compulsive disorder can also occur as a result of childhood obesity.In addition to the diseases associated with obesity, the economic consequences of obesity are enormous for families, health care systems, and the global economy. Direct medical costs include preventative, diagnostic, and treatment services related to overweight and associated co-morbidities. European nations spend 2-8% of their health care budgets on obesity, equating to 0.6% of their gross domestic product. In the United States, estimates based on 2008 data indicated that overweight and obesity account for $147 billion in total medical expenditure. This shows an increase from the $117 billion spent in the year 2000.While indirect costs of overweight and obesity on society can be significantly higher, they are often overlooked. These costs stem from childhood obesity continuing on to obesity in adulthood, which can then results in income lost from decreased productivity, reduced opportunities and restricted activity, illness, absenteeism, and premature death. In addition, there are high costs associated with the numerous infrastructure changes that societies must make to cope with obese people such as reinforced beds, operating tables and wheel chairs; enlarged turnstiles and seats in in public gathering spaces; and modifications to transportation safety standards.Obesity is reaching pandemic proportions across much of the world, and its consequences are set to impose unparalleled health, financial and social burdens on global society unless effective actions are taken to reverse the trend. Reducing the incidence of obesity in childhood can help children grow into adults with normal body weights and the tools necessary to sustain a health weight.Haerens, et al. explains the importance of school-based programs in dealing with the serious problem of childhood obesity and overweight. The school setting is known as having a powerful influence on student's eating and physical activities. Programs that may have a more positive impact are those that help increase physical activity and promote healthy foods in youth. Previous studies looking at the implementation of diet and exercise programs in schools were effective in changing food habits and increasing physical activity; however, few of these studies showed a reduction in body weight. The Planet Health study, conducted over a period of two years, focused on healthy life style and showed a reduction in obesity in girls but not in boys. The M-span study, a two-year study involving proper diet, exercise, and parental support showed a reduction of BMI only in boys. Haerens, et al. further explains that the above mentioned studies needed to be done in a more personalised manner in order to achieve more positive result; however, they are limited by the time consumption and financial demands necessary to carry out the proposed intervention.Haerens, et al. conducted a two year study of the effect of a program including physical activity, healthy eating, and parental support with a computer-tailored component on BMI and BMI z-score in boys and girls. This intervention resulted in significant reduction in BMI in girls only. Carlson, et al. conducted a 12-month web-based weight loss intervention program which included physical activity and dietary behaviour. The program was found to be a potential low cost method to positively impact public health and health behaviours. Furthermore, 55% of the participants in the intervention group compared with 35% in the control group made an improvement in moderate-to-vigorous physical activity and diet. Doyle, et al. conducted an randomised controlled trial evaluating the effects of an Internet delivered program targeting weight loss on 80 overweight ethnically diverse 12-17 year olds. BMI z-scores were reduced in the intervention group compared with the usual care group post intervention and the intervention group maintained their reduction in BMI z-score at the four month follow up; however, statistical significance was not achieved at the four month follow up due to improvements in weight loss in the usual care group over time.The United States Department of Health and Human Services report of 2009 indicates that school aged children spend an average of 7 hours and 11 minutes per day watching television, using a computer, and playing video games. Using these technology devices as educational tools could have significant impact by increasing knowledge about healthy choices.Web-based technology has become part of our children's life in the last decade providing the foundation to a large number of daily activities. The use of web-based technology may be one method to provide a more personalised intervention to reduce obesity in school-aged children.The search for previously conducted systematic reviews on the effectiveness of web based programs on obesity in children identified a systematic review conducted by An, et al., which included studies published between 1995 and April 2009. A critical appraisal of this systematic review determined it to be of reduced quality due to lack of transparency in reporting the details of the search strategy, inclusion and exclusion criteria, and assessment of the primary studies' methodological quality. The proposed systematic review will expand on the prior systematic review using the rigorous search strategy and assessment for methodological quality outlined below to identify the best available research to determine the effectiveness of web-based programs on childhood obesity. The current review will also seek to identify any more current research on the topic while expanding the inclusion criteria from the internet-based interventions included in An, et al. to other forms for web-based technologies, such as smart phones, that have becomeincreasingly popular with this population.The use of the web for communication purposes came into existence in 1991, but it was not really until the mid to late 1990's that information professionals understood its usefulness and the magnitude of a medium that would have far-reaching positive consequences. This systematic review will include studies published from 1991 to the present date to identify all relevant studies on this topic.