Objectives: Being overweight or obese is central to metabolic syndrome, and these characteristics constitute dominant risk factors for chronic diseases. Although behavioral factors, including eating habits and sedentary lifestyles, are considered to be determinants of obesity, the specific childhood factors that contribute to this condition have not been clearly defined. Methods: The subjects consisted of 261 children aged 7- 9 years who were recruited from an elementary school during October 2003. Information was obtained from their parents using a questionnaire focused on eating behaviors and lifestyle factors, additional data were also collected via anthropometric measurements and biochemical examinations, including blood tests. Results: A total of 48 (18.4%) of the 261 children were overweight, and 34 (70.8%) had at least one other component of metabolic syndrome. Eating behaviors emerged as significant lifestyle-related risk factors for being overweight or obese. Those who engaged in overeating more than twice per week had three times the risk of being overweight (odds ratio [OR], 3.10, 95% confidence interval [CI], 1.39 to 6.92), and those who ate rapidly had three times the risk of being overweight (OR, 3.28; 95% CI, 1.68 to 6.41). Those who had fewer family meals (fewer than 2?3/month) had a nine times higher risk of being overweight than those who had family meals more frequently (at least 1/day) (OR, 9.51; 95% CI, 1.21 to 74.82). Conclusions: This study showed that being overweight or obese during preadolescence is associated with a higher risk of metabolic syndrome and is related to unhealthy eating behaviors. Thus, weight-control strategies and healthy eating behaviors should be developed early in life to reduce the risk for metabolic syndrome.