Abstract In developed societies there is a growing interest in the control of body weight. However, alongside legitimate health concerns with respect to being overweight, some exhibit worries which are driven by fashion, vanity or peer pressure. This study investigates the relationship between concern over body weight, anthropometric parameters (real and desired) and the intake of energy (measured by means of a seven day food record), in a group of 130 young, female university students. The body mass index (BMI) of this group (21.3 ± 2.3 kg/m 2) fell within the normal range for such subjects though there was a fairly high percentage of young women (28.4%) with BMI < 20 kg/m 2 - a figure that qualifies these persons as slim or slightly underweight. Only 6.2% had BMI > 25 kg/m 2 indicating an excess of weight. However, 65% of subjects expressed a desire to lose some weight and 33% had at some time followed a slimming diet. Those who wished to lose weight showed a higher BMI than those who expressed no such desire, though 6.2% did show BMI < 20 kg/m 2. Only 35% of subjects did not wish to lose weight and did not think of themselves as fat. Although their BMI was fairly low (19.6 ± 1.4 kg/m 2) (P < 0.001 compared to those who wished to lose some weight), these subjects showed the best energy intake with respect to energy requirements. This was probably due to not undervaluing their diet. The mean BMI desired by subjects was 20.6 ± 1.9 kg/m 2 (calculated by subtracting the number of kg desired to be lost from true body weight). This value is at the lower limit of the normal range, indicating that subjects' ideal model of beauty was to be very thin. The desired BMI was very similar for all subjects, whether they thought themselves fat or not. These results show that a large percentage of the women studied (45.4%) would like to lose weight to a point where their BMI is below normal limits (20 Kg/m 2). This could be a danger to their health and to the maintenance of a satisfactory nutritional status.