Effect of soy-based meal replacement on weight loss: A systematic review and meta-analyses protocol

Background: Obesity is a complex and multifactorial disease that is strongly associated with multiple comorbidities and mortality. Weight reduction in overweight and obese patients was highly desired to minimize future complications. Meal replacement is emerging as one of the effective tools to promote weight loss. Isoflavones and soy protein present in soybean are able to promote weight loss and alleviate obesity. Aim: Our systematic review aims to investigate the weight loss effect of soy-based meal replacement among the overweight and obese population. Methods: We will conduct a systematic review of RCTs that evaluated the effect of a soy-based meal replacement on weight loss in overweight and obese patients. The primary outcome of this review is weight loss. Besides that, we will assess BMI, body fat, waist circumference and hip circumference as the secondary outcome. We will search PubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library. Two reviewers will independently screen titles and abstracts, review full texts, extract information and assess the risk of bias of individual studies. We will conduct meta-analyses using a random-effect model if sufficient data are available. If meta-analysis is not performed, we will present a systematic qualitative synthesis. Summary: This systematic review will identify the weight loss effect of soy-based meal replacement among the overweight and obese adult population. We expect the result may strengthen the evidence on the role of soy-based meal replacement in optimal body weight management.