Seasonal low mood patterns are commonly associated with reduced daylight exposure during colder months, altered circadian rhythm regulation, disrupted serotonin and melatonin signaling, reduced outdoor activity, inflammatory dietary burden, oxidative stress accumulation, and impaired sleep quality. Changes in seasonal light exposure can influence neurotransmitter production, hypothalamic signaling, cortisol rhythms, sleep timing, energy metabolism, and appetite regulation. Individuals experiencing seasonal mood changes may notice lower energy levels, increased fatigue, changes in appetite, difficulty concentrating, altered sleep timing, reduced motivation, and changes in emotional balance during darker winter months. The circadian system plays a central role in regulating sleep-wake cycles, hormone timing, neurotransmitter release, and metabolic synchronization. Reduced daylight exposure may alter melatonin timing and serotonin turnover while affecting hypothalamic signaling associated with mood stability and energy regulation. Oxidative stress and inflammatory signaling pathways may further contribute to neurological fatigue and mood imbalance by affecting mitochondrial energy production and neurotransmitter pathways. A whole food plant-based dietary pattern emphasizing colorful fruits, vegetables, legumes, mushrooms, seeds, herbs, and whole grains may help support neurotransmitter balance, circadian rhythm regulation, oxidative defense systems, mitochondrial support, and stable energy metabolism. Whole plant foods naturally provide polyphenols, flavonoids, carotenoids, anthocyanins, magnesium, folate compounds, amino acids, and fiber that participate in neurological signaling and antioxidant defense pathways. Berries, leafy greens, oats, brown rice, lentils, pumpkin seeds, walnuts, green tea, citrus fruits, mushrooms, turmeric, and cruciferous vegetables provide biologically active compounds associated with inflammatory balance, serotonin precursor support, circadian signaling, vascular circulation, and cellular stress defense systems. Fiber-rich whole foods may also support gut microbiome activity linked to neurotransmitter metabolism and short-chain fatty acid production. Stable meal timing, hydration support, regular exposure to daylight, balanced blood sugar regulation, and minimizing ultra-processed foods may further support circadian and neurological resilience during seasonal transitions. Seasonal mood shifts are also associated with stress-response signaling involving cortisol regulation, hypothalamic-pituitary-adrenal axis activity, inflammatory cytokine balance, and mitochondrial energy production. Plant foods rich in antioxidant compounds may help support cellular resilience and neurological recovery mechanisms linked to seasonal stress patterns and reduced environmental light exposure.