Extreme calorie restriction poses various dangers, including nutrient deficiencies and metabolic slowing. When the body receives insufficient calories, it can lead to muscle loss instead of fat loss, compromising overall health. Additionally, such restrictive practices can cause fatigue, dizziness, and a weakened immune system. Psychological effects, such as increased anxiety around food and potential development of eating disorders, are also significant concerns. Finally, extreme calorie restriction can disrupt hormonal balance, leading to complications like amenorrhea or osteoporosis.