The aim of this work was to evaluate peripheral and abdominal adipose tissue (AT) content detected by MRI in normal weight and obese children, to compare MRI data with simple anthropometric indexes and to estimate intrabdominal adipose tissue (IAT) influence on cardiovascular risk factors. The subjects were 23 obese and 21 normal weight children aged 10 to 15 years. The following measurements were carried out: MRI analysis at lumbar level with definition of subcutaneous adipose tissue (SAT) area and IAT area; arm fat area (AFA); thigh fat area (TFA) and waist/hip ratio from anthropometry. SAT (353 +/- 94 cm2) was predominant compared with IAT (49 +/- 21 cm2) in obese as well as in controls (SAT: 79 +/- 61 cm2; IAT: 22 +/- 11 cm2). No differences in SAT/IAT ratio were found for sex and puberty, either in obese subjects or in controls. SAT and IAT were significantly related in controls (r = 0.77, P < 0.0001), but not in obese subjects (r = 0.12, P = 0.59). IAT was related to total and LDL cholesterol and triglycerides levels (r = 0.54, P < 0.02, r = 0.60, P < 0.01, r = 0.46, P < 0.04, respectively) in obese children. AFA and TFA from anthropometry significantly underestimated AT compared with MRI in both groups. Methods agreement analysis showed unacceptable results for anthropometry. It was concluded that childhood obesity has a subcutaneous adipose pattern with no differences between the sexes. IAT already begins to have clinical significance since it has a relationship to some cardiovascular risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)