The study, the first of its kind in Costa Rica, appeared in a recent issue of the "Revista Panamericana de Salud Pública/Pan American Journal of Public Health," a monthly journal produced by the Pan American Health Organization (PAHO). The study was conducted by experts from the Ministry of Health's Institute for Research and Education on Nutrition and Health and the National University School of Sports Sciences. The lead author of the journal article, Hilda Patricia Núñez-Rivas, is with the Institute for Research.
The study sample, selected at random, included 1,780 children from the capital city of San José and other neighboring urban and rural areas, which together have the country's greatest concentration of elementary school children. Using the body mass index (BMI), which is calculated as weight in kilograms divided by height in meters squared, the study found that the overall prevalence of overweight and obesity were 34.5% and 26.2%, respectively. Children aged 7–9, boys, children from urban areas, and those of a middle or higher socioeconomic status had the highest prevalence levels of these conditions.
Noting the findings' direct relationship between socioeconomic level and the prevalence of obesity, the researchers note that "this association appears to be a typical behavior for a country in economic transition," and that during the early stages, the wealthier sections of society show an increase in the proportion of people with a high BMI. They add: "This tends to change in the later phases of the transition, with an increase in the prevalence of high BMI among the poor." The authors cite previous studies carried out in industrialized countries that indicate that socioeconomic status acts as "a powerful influence on the adoption of a healthy lifestyle."
Differences in lifestyles, the researchers believe, were also responsible for the higher rates of overweight and obesity found among urban children. "While some rural children walk long distances to attend school and spend more time in activities demanding high energy, such as agricultural work or walking in hilly areas, urban children take the bus to school and spend around three hours per day watching TV," they note, citing a 1997 study, and another from 2000, which revealed that the prevalence of sedentarism among urban Costa Rican males aged 13–18 was double the rate observed among their rural counterparts.
Studies conducted in the United States indicate that the relative risk of an obese child becoming an obese adult is six to seven times greater than that of his/her non-obese peers. Therefore, the researchers say, referring to their own study, "the likelihood that those children will also be overweight or obese as adults suggests there will be an increased need for treatment of associated morbidities in the future," including diabetes and cardiovascular disease.
Significantly, the prevalence of type 2 diabetes mellitus in Costa Rican adults is increasing, and coronary heart disease is the leading cause of death among adults.
"Costa Rica is facing a serious public health issue, which could have a marked effect on its economy," the study concludes. The resulting social burden, here and in other countries in transition, it says, will be considerable for a variety of reasons: "the absolute numbers at risk, the large reduction in life expectancy, and the fact that the problem particularly affects young individuals, who have a key role in promoting economic development."