Effect of Liquid Meal Replacements on Cardiometabolic Risk Factors: A Series of Systematic Reviews and Meta-analyses of Randomized Controlled Trials

Background: Liquid meal replacements (LMRs) provide a mixture of carbohydrate, fat and protein, along with added vitamins and minerals in liquid ready-to-drink form or powder formulas that require mixing. They are designed to mimic a low-calorie meal and serve as a quick and easy source of calories to consume. Behavioral strategy tools are important to assist obese individuals in losing weight and maintaining weight loss. There is evidence that LMRs contribute to weight loss and may reduce related cardiometabolic risk factors.

Need for proposed research: An earlier meta-analysis demonstrated that partial meal replacement plans produced significant weight loss and improved weight-related cardiometabolic risk factors. Several controlled trials have since investigated the effect of liquid meal replacements on body weight and weight-related risk factors for disease. There is a need to update of the evidence of the effect of LMRs on cardiometabolic risk to inform dietary guidelines and public health policy development.

Objective: To synthesize the evidence of randomized controlled trials of the effect of LMRs on body weight, blood pressure, glycemic control and established lipid targets.

Design: The systematic review and meta-analysis will be conducted according to the Cochrane Handbook for Systematic Reviews of Interventions and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Data sources: MEDLINE, EMBASE and The Cochrane Central Register of Controlled Trials (Clinical Trials; CENTRAL) will be searched using appropriate search terms supplemented by manual searches.