I've never tried ACV, but FWIW, I've never found any real studies that prove it to have much of an impact on fat loss. It's primary benefits are in aiding digestion, which is why most people direct it to be taken about 30 mintes prior to a meal.

If the type of ACV you're using is the good kind and actually made with apples (some acctually don't contain any, they're artificially flavored), then there's some debate about it aiding in fat loss. The pectin in apples is a mild appetite suppressant. Therefore, taking it prior to a meal would curb hunger slightly, possibly resulting in eating less at that meal.

IMO, for fat loss, it's not gonna do much.