Platinum Fit Keto However, one of the most effective weight loss pills is a carbohydrate blocker. Such carbohydrate blockers can be really effective and can make you lose those extra pounds, even if you find it difficult to change or control your diet. A carbohydrate blocker works by preventing your body from converting carbohydrates and sugars into energy. What I mean is that it prevents carbohydrates from being metabolized into fat. These carbohydrates are naturally passed as undigested foods.