The risks of extreme diets include potential nutritional deficiencies, loss of muscle mass, and negative impacts on mental health. Many extreme diets eliminate entire food groups, leading to a lack of essential nutrients that the body requires for optimal functioning. This can result in fatigue, lowered metabolic rates, and impaired immune function. Additionally, the psychological effects of strict dieting can lead to disordered eating patterns and a negative relationship with food. Long-term adherence to extreme diets is often challenging, causing individuals to regain weight and potentially create a cycle of yo-yo dieting.