One potential consequence of extreme dieting on health is the risk of nutrient deficiencies. When individuals drastically reduce caloric intake or eliminate entire food groups, they may not receive essential vitamins and minerals necessary for bodily functions. This can lead to a range of health issues, including fatigue, weakened immune response, and impaired cognitive function. Long-term extreme dieting can also negatively impact metabolism, making it harder for individuals to maintain a healthy weight in the future.