This study assess whether a small-group seminar intervention to prevent weight gain is effective in a general university student population, and to address the relative role of biological vs. lifestyle factors in predicting weight gain in humans.

Inclusion Criteria:

• First year students at the Université de Sherbrooke.

Exclusion Criteria:

• Presence of diseases or medications that would be expected to affect weight (cystic fibrosis, diabetes, inflammatory bowel diseases, anorexia nervosa, bulimia, etc.).
• Pregnancy or planning a pregnancy in the next two years.
• Unable to give an informed consent.