Carb blockers are dietary supplements that claim to prevent the digestion of carbohydrates, allowing calories from carbs to pass through the body undigested. The article reviews the 5 best carb blockers of 2014, including Bean-O, Phase 2 Carb Controller, Carb-RX, Carb-X, and Advanced Carb Blocker. These supplements contain different active ingredients like white kidney bean extract, citrus extract, and green coffee bean extract that are said to block carb absorption in the digestive system.