Obesity and health behaviors that influence energy balance (diet, exercise, and dieting to lose weight) were examined in a population of 2108 and 2539 working men and women in relation to socioeconomic status (SES). The hypothesis investigated was that the inverse relationship between SES and obesity observed in a number of studies is due to the fact that the distribution of obesity relevant health behaviors differs by social class. Body mass index (BMI), as expected, was found to be inversely related to SES. Higher SES was also associated with several behaviors that contribute importantly to energy balance. High SES respondents reported a lower fat diet, more exercise, and a higher prevalence of dieting to control weight. However, lower smoking rates were observed in upper SES men and women and higher alcohol consumption was reported in upper SES women. Both of these associations appear to be inconsistent with the hypothesis that the inverse association between SES and obesity is caused by differences in health behaviors. In multiple regression analyses, SES remained a significant predictor of BMI after controlling for all measured health behaviors. Weaknesses in the methodologies for measuring health behaviors and possible effects of obesity itself on social mobility are suggested as possible explanations for the residual association between obesity and SES.