Why are there no traffic lights for protein, carbs or fibre?

Unlike fat, saturated fat, sugar and salt, high intakes of carbohydrates, protein and fibre aren't directly associated with negative health outcomes, so most of us don't need to moderate our intake of these nutrients. In fact, especially in the case of fibre, many of us could do with eating more! Carb-rich foods are a great source of B-vitamins and energy, protein is essential for muscle growth and recovery, and fibre promotes a healthy heart and gut.