We investigate the roles of consumer knowledge and sociodemographic factors in the consumption of meat products at home and away from home, using data from the Continuing Survey of Food Intakes by Individuals and its companion Diet and Health Knowledge Survey conducted by the US Department of Agriculture. The sample used contains individuals not consuming some of the products. In addition, diet knowledge is potentially endogenous because it is likely to be affected by unobserved factors which also affect meat consumption. It is well known that traditional estimation procedures not accounting for censored dependent variables or simultaneity produce biased estimates. These econometric issues are addressed by developing a simultaneous -equations system, estimated with the maximum simulated likelihood procedure. Results suggest endogeneity of knowledge and support the system approach to the estimation of demand functions for meats. Health knowledge decreases consumption of beef and pork at home and away from home; it increases consumption of poultry at and away from home but does not affect fish consumption in either occasion. Our findings on the effects of sociodemographic factors are in general consistent with a priori expectations: men eat more meat and fish than women, meat and fish consumption generally declines with age among adults, and regional and racial/ethnic differences in meat and fish consumption are observed. The simultaneous-equations model can be extended to one with multiple endogenous variables and can be a useful tool in other analyses of consumer demand with micro survey data, which have become available in many developing countries.