To determine the relationship between nutritional status and ethanol consumption, 250 chronically alcoholic men (mean age 41 +/- 11 years) entering an alcoholism treatment program were studied. A control group of 100 male volunteers (mean age 40 +/- 10 years) was also evaluated. Detailed clinical history, laboratory analysis and nutritional status assessment were carried out in each case and control. In addition, ethanol-related diseases such as liver disease, chronic pancreatitis, cardiomyopathy, myopathy and peripheral neuropathy were ruled out in all patients. The mean daily ethanol consumption of the alcoholics was 235 +/- 62 g over an average of 19 years. All of them belong to a very stable, middle-class working group of men. Only 25 (10%) alcoholics showed evidence of energy malnutrition, 15 (6%), of protein malnutrition, and 6 (2%) of both. In the multivariate analysis, the only independent factors for the development of malnutrition were the total lifetime dose of ethanol and calorie intake (ethanol excluded) (P < 0.01; both), as well as cirrhosis (P < 0.01) when protein malnutrition was considered. Alcoholic cirrhosis was diagnosed in 20 cases, skeletal myopathy in 117, dilated cardiomyopathy in 20 and peripheral neuropathy in 41. When patients with ethanol-related diseases were excluded, no significant differences in nutritional parameters were observed between chronic alcoholics and controls. We conclude that malnutrition is not as frequent as previously thought in middle socioeconomic class male alcoholics and its existence may be considered as another consequence of ethanol intake or secondary to the alcohol-related diseases.