Background: The pursuit of effective weight management strategies is critical for obesity and chronic disease prevention. The impact of meal timing on weight loss has gained popularity, but its long-term efficacy remains uncertain.
Objective: Investigate how meal timing affects weight and metabolic health via systematic review and meta-analysis.
Methods: Searched Medline, Embase, CINAHL, and Cochrane CENTRAL databases until October 17, 2023 for randomized controlled trials that examined meal timing effects over ≥12 weeks in adults. The primary outcome was weight change, with a focus on time-restricted eating (TRE), meal frequency, and calorie distribution.
Results: Analysing data from 69 reports of 29 randomized controlled trials with 2,485 participants, this meta-analysis found that TRE, reduced meal frequency, and earlier daily calorie consumption were associated with significant weight loss, with mean differences (MD) of –1.38kg, –1.84kg, and –1.75kg, respectively. A feeding window ≤8 hours/day resulted in greater weight loss (MD –1.88 kg, 95% CI –2.72 to –1.04) compared to >8 hours/day (MD –0.71 kg, 95% CI –1.42 to 0.00), with greater benefits for individuals with higher initial BMI. However, the variability in study quality and instances of high risk of bias warrant cautious interpretation of results.
Conclusions: This meta-analysis highlights that meal timing strategies, especially TRE can lead to weight loss. For healthcare professionals, these findings could inform dietary recommendations aimed at better weight management.
Protocol Registration Number: CRD42023474391 (PROSPERO)