Obesity is associated with an increased preference for sweet and high-fat foods, and the most consistent evidence has been the shift away from these calorie-dense foods in both animal and human studies after RYGB. Self-reporting is the most common method used to record food preferences in humans, while more direct approaches have been used in animal work. This methodological heterogeneity may give rise to inconsistent findings. Future studies in humans should focus on direct measures to permit corroboration of mechanistic insights gained from animal studies.