i dont possibly think it can change that much can it i weigh 175 lbs im 5 foot 8 male and i dont look fat plus i weight train alot but my question is are they accurate because im pretty strongand i dont think im possibly 22 percent, oh yea what do you have to keep constant before jumping on one of them empty stomach is one thing but what else, should you not exercise before taking it, should you be well hydrated its confusing