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 the Mediterranean diet (OR: 0.86; 95 % CI, 0.79, 0.93; P < 0.001; I² = 32.68 %), a high-quality diet (OR: 0.66; 95 % CI, 0.48, 0.90; P = 0.010; I² = 84.62 %), and an 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, the dietary glycemic index (OR: 1.16; 95 % CI, 1.08, 1.25; P < 0.001; I² = 0.0 %), the 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 is associated with decreased insomnia symptoms prevalence, while adherence to an unhealthy pattern is associated with an increased prevalence of insomnia symptoms.