The impact of 3 different dietary interventions on overweight or obese adults: A network meta-analysis

Abstract

Objective: This network meta-analysis aims to investigate and compare the effectiveness of 3 dietary interventions - Mediterranean, ketogenic, and low-fat diet - on overweight and obese adults, with a comparison to traditional low-calorie diet.

Methods: A systematic review was conducted in both Chinese and English databases, including the China National Knowledge Infrastructure (CNKI), Wanfang Database, China Science and Technology Journal Database (VIP), SinoMed, PubMed, Web of Science, Cochrane Library and Embase to identify relevant randomized controlled trials (RCTs) up to January 31, 2024. Two researchers independently screened and extracted data from the identified literature. The quality of these studies was assessed using the Cochrane bias risk assessment tool. A random-effects network meta-analysis was performed using Review Manager 5.4.1 and Stata 16.0 software.

Results: A total of 17 randomized controlled trials involving 5802 subjects were included in this study. The network meta-analysis revealed a descending order of effectiveness for reducing body weight (BW), body mass index (BMI), and waist circumference (WC): ketogenic diet > low-fat diet > low-calorie diet > Mediterranean diet.

Conclusions: The ketogenic diet was identified as the most effective intervention for reducing BW, BMI, and WC in the studied dietary comparisons. It consistently showed superior outcomes, ranking highest in effectiveness among the 4 evaluated dietary approaches. Nevertheless, additional high-quality randomized controlled trials are necessary to validate these findings.

Figure 1.

PRISMA flowchart of the study selection process. CNKI = China National Knowledge Infrastructure, PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses, VIP = Wanfang Database, China Science and Technology Journal Database.

Figure 2.

Risk of bias assessment.

Figure 3.

Network evidence diagram. BMI = body mass index, KD = ketogenic diet, LCD = low-calorie diet, LFD = low-fat diet, MD = Mediterranean diet, MFD = moderate-fat diet, VLCKD = very low calorie ketogenic diet.

Figure 4.

Network meta-analysis ranking results (body weight). KD = ketogenic diet, LCD = low-calorie diet, LFD = low-fat diet, MD = Mediterranean diet, MFD = moderate-fat diet, VLCKD = very low calorie ketogenic diet.

Figure 5.

Network meta-analysis ranking results (BMI). BMI = body mass index, KD = ketogenic diet, LCD = low-calorie diet, LFD = low-fat diet, MD = Mediterranean diet, MFD = moderate-fat diet, VLCKD = very low calorie ketogenic diet.

Figure 6.

Network meta-analysis ranking results (waist circumference). KD = ketogenic diet, LCD = low-calorie diet, LFD = low-fat diet, MD = Mediterranean diet, MFD = moderate-fat diet, VLCKD = very low calorie ketogenic diet.