Well there is no doubt that the body slows metabolic rate when you reduce calories or lose weight / fat. (leangainsguide.com)
Many women tend to have somewhat slower metabolic rates than men, and statistically, metabolic health issues affect more women than men. (econugenics.com)
This causes a cascade of reactions and hormones that do everything from slowing your metabolic rate, to making you hungry enough to quit that diet and put back the fat you lost. (abbylangernutrition.com)