Determining risk factor frequency regarding obesity and being overweight in university students. A cross-sectional analytic study was carried out on 821 students from the University of Colima. Some variables analysed were age, gender, alcoholism, smoking and weight-control drug use. 821 students were included (380 male, 441 female), 20.9±2.5 average age. 27.8 % of males were overweight and 14.7 % suffered from obesity; this was 17 % and 5.2 % in females, respectively. Smoking (2.1 OR; 1.4-3.8 95 % CI; p=0.01) and alcoholism (2.1 OR; 1.2-3.6 95 % CI; p=0.003) were associated with being overweight and being obese. Weight-control drug use was a protective factor in both genders (0.4 OR; 0.2-0.8 95 % CI; p=0.01); diet control was only a protective factor in women (2.2. OR; 1.1-3.4 95 % CI; p=0.01). 31.6 % of university students were overweight and suffered from obesity. Smoking and alcoholism in males were associated with being overweight and suffering from obesity. Weight-control and diet-control drug use were protective factors.