PURPOSE:To investigate the effect of lifestyle habits in childhood Metabolic Syndrome (MTS). DESIGN AND METHODS:Descriptive correlation study with 480 participants (5-12 years old) using a specially designed questionnaire was conducted. Anthropometric and biochemical analyses were performed. RESULTS:Fifteen percent of children exhibited predisposition for MTS. Regarding sleep habits, logistic regression analysis (LRA) showed that hour of sleep -before 22:00- was associated with decreased waist circumference (WC%) (p = .026). Midday siesta was negatively correlated with systolic (SBP) (p = .001) and diastolic blood pressure (DBP) (p = .046). In children without MTS, lack of sleep and night time sleep was positively correlated with DBP (p = .044) and fasting blood glucose (FBG) (p = .005). Regarding nutrition habits, fast food consumption was positively correlated with SBP (p = .006) and meat consumption was positively correlated with both Body Mass Index% (BMI%) (p = .038) and WC% (p = .023). LRA showed that fruit (p = .001) and legume (p = .040) consumption was associated with decreased FBG; fish consumption with decreased Low Density Lipoprotein (LDL) cholesterol (p = .031), vegetable (p = .054) and cereal consumption (p = .012) with decreased DBP. In children with MTS, fruits were associated with increased FBG (p = .034). In children without MTS, meat consumption was associated with increased LDL (p = .024), cereal with increased WC% (p = .002) and olive products with increased High Density Lipoprotein (HDL) cholesterol and BMI% (p = .037). CONCLUSIONS:The adoption of both balanced diet and sleep habits seemed to be crucial for the prevention of MTS. PRACTICE IMPLICATIONS:Clinical health nurses could develop and implement preventive intervention programs in order to avoid metabolic complications in adulthood.