Dieting behavior was studied in 166 young college women, 18 to 24 years old. The women were divided into three groups on the basis of the amount of time they had spent dieting during the previous school year (8 months). Of the whole population, 18.1% had spent more than half the time dieting (chronic dieters), 45.2% had dieted 50% of the time or less (periodic dieters), and 36.7% had not dieted during that period (nondieters). Physical measurements, background characteristics, and weight-loss experiences were compared among the three groups, following an anthropometric measurement session and administration of a self-report questionnaire. The chronic and periodic dieters weighed an average of 12 lb more than the nondieters and were more likely to be obese. The dieters also had greater triceps skinfold thickness, arm circumference, arm muscle diameter, and arm muscle circumference measurements. Women in both dieting groups were more likely than the nondieting group to consider themselves as having been overweight during their childhood and adolescent years and to consider at least one parent overweight. The average age at the time of the first reducing diet was 16.2 years. The four most commonly tried weight-loss approaches were exercise, moderate calorie restriction, fasting/starvation, and diet pills or supplements. The major sources of information on reducing diets were magazines or newspapers and friends or relatives.