Many proponents of low-carb dieting suggest that carbohydrate-rich foods are the cause of our nation's obesity problem; however, the Japanese, who enjoy the lowest obesity rates in the world, consume far more carbohydrates than Americans.
Many people are under the assumption that protein is the key ingredient in building muscle. However, low-carb diets tend to make muscles flatter and less dense - you need the carbs to increase your muscle mass.
Low-carb diets can cause your body to go into a dangerous metabolic state called ketosis, since your body burns fat instead of glucose for energy. Further, too much protein can put a strain on kidneys, putting you at risk for several kidney-related diseases.