I am famous for that it's all mental, try pinching your skin upper chest and thighs, you will be able to tell the diff between fat/water. When your skin gets thin, its amazing the difference. It might take awhile to tell the diff but, you can. I just learned that, from my trainer for a contest, he just kept pulling my skin on my chest to see if I was retaining water--so weird, but drinking more water you can notice in one day the diff.