Incretine-based therapies are frequently used to treat patients with type 2 diabetes. Some of these drugs are used to induce weight loss. Liraglutide, a glucagon-like peptide 1 receptor agonist, was recently approved for the treatment of obesity. Smoking cessation is associated with weight gain. The mechanism responsible for the increase in body weight post cessation remains unclear. While increased caloric intake may play a role, weight gain may also be linked to nicotine, which has been shown to stimulate smokers basal metabolic rate. The effect of incretines on body weight and energy metabolism after smoking cessation is unclear. Recently published data suggests that incretine hormones may not be involved in the above mentioned changes.