Mapping evidence and identifying risks: A systematic scoping review of meal replacements in type 2 diabetes

Type 2 diabetes (T2D) is a major health concern globally and its prevalence is expected to continue to escalate. Lifestyle intervention is an integral part of T2D management. Meal replacements are often used as part of lifestyle intervention programs in T2D and weight management programs. There are various trials being carried out to date; however, a thorough review regarding the usage of meal replacement on its types, dosage and associated outcomes and adverse events is still lacking.

To provide a comprehensive overview on existing studies regarding meal replacement usage among patients with T2D, and map out glycemic and weight-related outcomes along with adverse effects incidences.

This scoping review is conducted based on Arksey and O'Malley's seminal framework for scoping reviews. A systematic search has been done for studies published between January 2020 and January 2024 across six online databases (Cochrane Library, PubMed, Science Direct, Scopus, Web of Science and Ebscohost Discovery) using specific keywords. Two researchers independently assessed the eligibility of the studies and extracted the data. The selected articles and extracted data were reviewed by all researchers.

The initial search resulted in an initial count of 53922 articles from which 133 articles were included in this review after eligibility screening. Included studies were categorized based on meal replacement type into low calorie/energy, low glycemic index, protein-rich, low-fat, diabetes-specific formulas, and combined lifestyle intervention programs. Fifty-nine studies reported improvements on hemoglobin A1c, and 70 studies reported positive changes in weight or BMI after the meal replacement intervention. The combination of meal replacements with education, counseling or structured lifestyle interventions has proved to be effective. Only 13 studies reported occurrence of adverse events related to the intervention. Most of the reported incidents were of mild occurrences with constipation being the most reported adverse event.

The results suggest that meal replacements, especially when combined with lifestyle intervention programs and counseling, are an effective and safe strategy in glycemic and weight management among patients with T2D.