REVIEW QUESTION/OBJECTIVE:: (i) To systematically review and rank the efficacy of different types of lifestyle intervention strategies on weight outcomes (weight, body mass index [BMI], waist circumference and waist-to-hip ratio) in people with psychosis. (The efficacy of different types of lifestyle intervention strategies will be ranked by comparing the effect size on weight outcomes in people with psychotic disorders.) (ii) To stratify lifestyle interventions that target weight outcomes (weight, BMI, waist circumference and waist-to-hip ratio) in people with psychosis, according to their inclusion of dietary information that adheres with Australian Dietary Guidelines (National Health and Medical Research Council. Eat for Health, Australian Dietary Guidelines Canberra National Health and Medical Research Council; 2013).Specifically, the review question is: What lifestyle intervention strategies targeting weight outcomes (weight, BMI, waist circumference and waist-to-hip ratio) in people with psychosis compared to no treatment or various control conditions have the best efficacy?