Summer fatigue linked to metabolic overload and hormone-driven hunger

During hot weather the body works harder to maintain temperature, leading to loss of water and electrolytes such as sodium, potassium and magnesium. This dehydration reduces energy levels and can cause persistent tiredness, especially when combined with an unbalanced diet, exposure to pollutants, alcohol, or stress. When fatigue does not improve with rest and hydration, medical evaluation may be needed to rule out metabolic overload.

Lack of sleep also disrupts hunger hormones. Ghrelin, the “hunger hormone” produced in the stomach, rises, while leptin, the satiety hormone from fat cells, falls. The resulting hormonal imbalance can increase appetite by up to 24 % and add roughly 300 calories per day, with a strong preference for high‑calorie, carbohydrate‑rich foods. An additional boost from the endocannabinoid system heightens the pleasure response to such foods, further driving overeating when people are exhausted.