Insomnia involving difficulty falling asleep, staying asleep, or maintaining restorative sleep is strongly associated with circadian rhythm disruption, elevated stress signaling, neurotransmitter imbalance, metabolic dysregulation, inflammatory signaling, and altered autonomic nervous system activity. Sleep initiation and maintenance are influenced by coordinated interactions between melatonin production, serotonin turnover, cortisol regulation, glucose stability, neurotransmitter cycling, and neuronal oxidative balance. Chronic exposure to artificial light at night, high-sugar processed foods, stimulant-heavy dietary patterns, alcohol intake, excess saturated fat, and inconsistent meal timing are all associated with impaired sleep quality and delayed sleep onset. Research has demonstrated that diets emphasizing whole plant foods are associated with improved sleep duration, lower inflammatory burden, better glucose regulation, improved vascular function, and healthier circadian signaling. Fiber-rich foods support gut microbiome diversity and short-chain fatty acid production, both of which influence serotonin and melatonin pathways through gut-brain communication systems. Complex carbohydrates from intact whole grains, legumes, vegetables, and fruits may support stable nighttime glucose availability and reduce sympathetic nervous system activation during sleep periods. Magnesium-rich plant foods including pumpkin seeds, spinach, oats, lentils, and leafy greens are associated with neuromuscular relaxation, neurotransmitter regulation, and maintenance of normal sleep architecture. Tryptophan-containing foods including oats, pumpkin seeds, chickpeas, and lentils provide amino acid substrates involved in serotonin and melatonin synthesis pathways. Polyphenol-rich berries, tart cherries, green tea compounds, and flavonoid-containing vegetables may help regulate oxidative stress and inflammatory signaling associated with poor sleep quality. Sleep disruption is also associated with elevated cortisol signaling, impaired autonomic balance, insulin resistance, and dysregulated circadian clock gene expression. Chronic inflammatory signaling involving NF-κB and stress-response pathways has been observed in individuals with persistent sleep disruption. Plant-based dietary patterns emphasizing stable glycemic intake, antioxidant-rich foods, hydration, mineral balance, and anti-inflammatory phytochemicals may support healthier circadian alignment and improved sleep maintenance. Whole-food plant-based nutrition strategies emphasizing vegetables, legumes, intact grains, fruits, seeds, herbs, and polyphenol-rich foods may support neurotransmitter production, neuronal recovery, oxidative balance, vascular circulation, and nighttime parasympathetic activity. Consistent meal timing, reduction of ultra-processed foods, improved mineral intake, and higher fiber consumption are associated with better sleep efficiency and healthier sleep onset patterns.