Finding nutritious, delicious snacks on the go was always a challenge for me, so i created thinkThin Protein bars. With thinkThin Lean Protein & Fiber bars, my goal was to create a bar with the perfect balance of protein and fiber to help keep you full and satisfied - all for 150 calories. Plus, each bar is gluten-free and made with 100% non-GMO ingredients. 150 Calories. 10g Protein. 5g Fiber. 5g Sugar.