The effect of different dietary restriction on weight management and metabolic parameters in people with type 2 diabetes mellitus: a network meta-analysis of randomized controlled trials.

Background: Type 2 diabetes mellitus (T2DM) is a globally prevalent chronic condition. Individuals with T2DM are at increased risk of developing complications associated with both macrovascular and microvascular pathologies. These comorbidities reduce patient quality of life and increase mortality. Dietary restriction is a principal therapeutic approach for managing T2DM. This study assessed the effects of various dietary regimens on body weight and metabolic profiles in T2DM patients, aiming to determine the most beneficial interventions for enhancing clinical outcomes and overall well-being.

Methods: We conducted a literature search in PubMed, Embase, and Web of Science from 2003 to April 15, 2024. The risk of bias was assessed via the Revised Cochrane risk-of-bias tool for randomized trials (RoB2). The certainty of the evidence was appraised via the confidence in network meta-analysis (CINeMA) framework. Intermittent fasting (IF) was directly compared with continuous energy restriction (CER) via Review Manager 5.4. Network meta-analysis was statistically assessed via R Studio 4.3.3 and STATA 14.0.

Results: Eighteen studies involving 1,658 participants were included. The network meta-analysis indicated that intermittent energy restriction, the twice-per-week fasting, time-restricted eating, fasting-mimicking diets (FMD), and CER interventions were more effective than conventional diets. Direct comparisons revealed that IF was as effective as CER for reducing glycated haemoglobin A1c, body weight, and body mass index. The results of the cumulative ranking analysis demonstrated that FMD had the greatest combined intervention effect, followed by TRE in terms of overall effectiveness.

Conclusions: Both IF and CER exert positive influences on weight control and metabolic profile enhancement in individuals with T2DM, with FMD as part of IF demonstrating the greatest impact. To substantiate these findings, more rigorous randomized controlled trials that directly compare the effects of the different IF regimens with one another and with the CER regimen are needed.