Diet Protein is arguably the most sophisticated diet protein shake available today. Reflex Nutrition have used the latest advances in protein and weight loss technology to bring you a product that?s specifically designed to help you achieve a healthy, well defined and toned body. Diet Protein is arguably the most sophisticated diet protein shake available today. Reflex Nutrition have used the latest advances in protein and weight loss technology to bring you a product that?s specifically designed to help you achieve a healthy, well defined and toned body.