I am not familiar with this protocol but when my nail get fragile I take Jello - nowadays I buy the flavor free packages and I put them into ibiscus tea (for the color and bowel benefits) + xylitol (to make it sweet - i ve never tried with stevia but that would be plan b).
Chromium supplement helps with cravings. So does making sure you stay away for 3 solid days and then your metabolism adjusts.