Dietary patterns and insomnia symptoms: A systematic review and meta-analysis

We aimed to systematically review and synthesize the available evidence regarding the link between dietary patterns and insomnia symptoms among the general population using observational studies. We reviewed 16,455 references, of which 37 studies met inclusion criteria with a total sample size of 591,223. There was a significant association of Mediterranean diet (OR: 0.86; 95% CI, 0.79, 0.93; P < 0.001; I2 = 32.68 %), high-quality diet (OR: 0.66; 95% CI, 0.48, 0.90; P = 0.010; I2 = 84.62 %), and empirically-derived healthy dietary pattern (OR: 0.91; 95% CI, 0.85, 0.98; P = 0.010; I2 = 57.14 %) with a decreased risk of insomnia symptoms. Moreover, dietary glycemic index (OR: 1.16; 95% CI, 1.08, 1.25; P < 0.001; I2 = 0.0 %), dietary glycemic load (OR: 1.10; 95% CI, 1.01, 1.20; P = 0.032; I2 = 74.36 %), and an empirically-derived unhealthy dietary pattern (OR: 1.20; 95% CI, 1.01, 1.42; P = 0.040; I2 = 68.38 %) were linked with a higher risk of insomnia symptoms. Most individual studies were of good quality (NOS) but provided very low certainty of evidence (GRADE). Consistent data reveals that following healthy diets reduces insomnia symptoms risk, while adherence to an unhealthy pattern increases it.