Chronic excessive calorie restriction can lead to various health issues, including nutrient deficiencies, decreased energy levels, and a slower metabolism. It may also result in muscle loss as the body starts using muscle protein for energy. Psychological effects such as increased irritability, anxiety, or signs of eating disorders can occur due to constant hunger and food restrictions. Ultimately, while aiming for weight loss, prolonged deficits can lead to physical and mental fatigue, making sustainable health management more challenging.