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Daytime routines impact sleep and energy levels
Feeling persistently tired may not solely stem from poor nighttime sleep. Emerging research suggests daily habits-such as diet, exercise, and meal timing-play a critical role in restfulness and overall vitality.
Iron deficiency and fatigue
Approximately one-third of the global population suffers from insufficient iron levels, with higher risks among infants, menstruating women, pregnant individuals, endurance athletes, vegetarians, and frequent blood donors. Iron deficiency, including its severe form-iron-deficiency anemia-can cause fatigue, restlessness, and disrupted sleep.
Physicians recommend testing ferritin (an iron-storage protein) or hemoglobin levels if fatigue persists despite improved sleep habits. Heme iron, found in meat, fish, and eggs, is most readily absorbed, while non-heme iron from plant sources (e.g., beans, leafy greens) benefits from pairing with vitamin C-rich foods to enhance absorption.
Diet's role in sleep quality
Large-scale studies link higher fruit and vegetable consumption to better sleep, while fast food and sugary drinks correlate with poorer rest. The Mediterranean diet-rich in vegetables, fruits, nuts, legumes, and whole grains-has been associated with more consistent and restorative sleep.
Conversely, individuals sleeping fewer than five hours nightly tend to consume lower levels of essential nutrients, including iron, zinc, magnesium, and vitamin C. A Swedish study of 15 young men revealed that high-fat, high-sugar diets altered brain waves during sleep, reducing deep sleep quality. Switching to a low-fat, low-sugar diet reversed these effects.
Randomized trials further support these findings. One study of over 1,000 young adults found that women increasing their daily fruit and vegetable intake to at least six servings were twice as likely to report improved insomnia symptoms and faster sleep onset. Another trial observed children on a diet including green vegetables five times weekly reported feeling more rested, likely due to vitamins A and C enhancing mineral absorption.
Exercise and sleep benefits
A 2015 meta-analysis of 66 studies concluded that even short bouts of exercise helped participants fall asleep faster and sleep longer, with more pronounced benefits for those with preexisting sleep complaints. Moderate-intensity workouts three times weekly appeared most effective, and evening exercise-up to two hours before bedtime-did not disrupt sleep.
Beyond sleep improvements, physical activity independently boosts perceived energy and restfulness, regardless of actual sleep quality.
Substance use and sleep disruption
Smoking is linked to difficulty falling asleep and reduced slow-wave (restorative) sleep. Alcohol, while initially sedating, disrupts sleep architecture over time. Regular consumption increases insomnia risk, and even a single drink before bed alters sleep physiology, reducing REM sleep and causing more nighttime awakenings. Alcohol also exacerbates sleep-disordered breathing conditions like sleep apnea.
Meal timing and mental alertness
Breakfast consumption has been consistently associated with improved memory, concentration, and reduced fatigue. A study of 127 medical students found those who ate breakfast reported lower fatigue levels than those who skipped it. Similarly, research involving 1,800 Taiwanese graduate students linked irregular eating times to increased fatigue.
While observational studies cannot establish causation, growing evidence suggests circadian rhythms influence eating patterns, and meal timing reciprocally affects circadian regulation. For those struggling with tiredness, incorporating a nutritious breakfast-such as eggs or porridge-may offer a simple, effective remedy.
