A lack of essential nutrients can significantly affect mood and energy. Nutritional deficiencies, such as low levels of vitamins like B12 and D, are linked to symptoms of depression and fatigue. Inadequate nutrient intake can alter neurotransmitter production, diminishing mental clarity and affecting overall emotional stability. Moreover, insufficient energy from food can lead to feelings of lethargy, making daily tasks feel overwhelming. Thus, maintaining a balanced diet rich in whole foods can help sustain optimal energy levels and improve psychological well-being.