Keto Fire But dieters can get those same results in a healthier way. For instance, if they want quick weight loss, they should restrict their carb intake. The key is they have to know which carbs to restrict. They’ll have to restrict their intake of white flour products, rice, potatoes and sugar. Those are called refined carbohydrates. They will need to replace these carbs with complex carbohydrates – meaning fruit, vegetables and high fibrous cereals.