The Se and Zn content of several foodstuffs collected in Northern Italy was evaluated by Atomic Absorption Spectrometry, these foodstuffs, employed in markedly hypocaloric diets with high fiber content, were utilized in the medium-term treatment of obesity. The plasma and erythrocyte selenium and zinc contents were evaluated in sixteen non-hospitalized obese patients over a 6-week period. Dietary regimens of 700 Kcal/day for 21 days followed by 1050 Kcal/day for 42 days were imposed. In spite of the drastic reduction in calorie intake, significant elevations in plasma (p less than 0.05) and erythrocytes (p less than 0.005) Se were observed after 9 weeks of treatment; plasma Zn, on the contrary, shows a slight but significant reduction (p less than 0.05) at the end of the experimental period. Findings suggest that, from the point of view of the microelement status, the balanced low-calorie diet with high fiber content is a mild, but quite adequate method for the treatment of subjects in good health even for long periods.