Technical Abstract: Male soldiers in training and field operations reduce intake of rations (food) because of exposure to intense physical, mental and environmental stressors. Assessments of nutrient intake during these activities reveal that zinc, magnesium and calcium intakes are less than recommended for military personnel. This paper describes the physiological and psychological effects of restriction and supplementation of these minerals, as well as iron, selenium and copper that are of interest to the military. The adverse effects of restricted intakes of these minerals, determined in either observational studies relating mineral intake or status with function or controlled depletion and repletion studies and measures of function in men, are similar to the findings of decreased physical and mental performance observed in studies of soldiers in field training. One recommendation to increase the mineral intakes of soldiers during field operations is to raise the mineral nutritional density of rations to recommended levels (Dietary Reference Intakes) to be contained in the reduced energy rations for men (1500 kcal). Other suggestions are to develop nutrient-fortified foods and an active nutrition education program, use behavior modification to foster healthful eating habits, and encourage leaders and peers to be models of healthful eating behaviors. This information will be useful to food scientists and military leaders who are actively working to develop a new first assault ration that will promote the health and performance of male soldiers participating in intense field operations.