Sinister Labs SINFIT protein bars are some of the best tasting protein bars on the planet. We're not the only ones who think that as Fitness Informant has also ranked them of the best protein bar of 2018. Besides having a great taste, they contain more protein than most bars (30g) with it's protein sources coming exclusively from Whey Protein Concentrate and Whey Protein Isolate. SINFIT bars also have a tasty outside coating with soft, chewy inside center. Clocking in at 350 calories per bar, these may not be optimal for a low calorie diet, but they are a tasty way to get some extra protein.