Metabolic and Behavioural Effects of CONTRAVE as Potential Mechanisms of Weight Loss in Adults With Obesity

Obesity is a common chronic disease linked with increased risk for other illnesses and earlier death. Our team and others have shown that many bodily and psychological changes occur when individuals are on calorie-restricted diets. These changes might undermine dietary adherence and help to explain the relatively poor long-term efficacy of diets. These include increased appetite, increased food 'value' and 'wanting' that leads to overconsumption. Other factors include more sensitive sensory cues (e.g., smelling), higher food liking and craving, and a drop in resting energy expenditure (REE). REE has been shown to predict weight regain. The standard care for obesity may include the use of the weight-loss drug CONTRAVE®. The Federal Drug Agency (FDA) and Health Canada have approved this drug for weight management and obesity treatment. Although CONTRAVE® was designed to reduce appetite, food-related impulsivity and cravings, its mechanisms of action are unclear. In other words, the effects of CONTRAVE® on REE, executive function, and brain changes remain unknown in humans. A better understanding of how this drug works on the brain and body could lead to improvements in obesity management in the future. As such, the goal of this research is to study the effects of 4 weeks of CONTRAVE® (+ diet program) vs. control (placebo pill + diet program) on mood, body composition changes, biological/metabolic measures, and brain measures. Adults aged 18-64 with obesity will be randomized to one of two groups: diet + CONTRAVE® (CONTRAVE®, 20 participants) or diet + Placebo (Placebo, 20 participants). Both groups will be assigned the same study procedures for the entire study duration. The only difference is that Group 1 will receive CONTRAVE® while Group 2 will receive a placebo (non-medical) pill. The study design and intervention is as follows: Participants who meet all the telephone screening criteria will be invited to the Clinical EEG \& Neuroimaging Laboratory at The Ro