I constantly crave and eat mashed potatoes and french fries, is that safe for me to eat during my pregnancy?

Cravings: Its not uncommon to have certain cravings during pregnancy. The only issue in your case is that you are craving starches, which might lead to excessive pregnancy weight gain and increased baby size. Big babies mean higher C-section rate, more likely to cause vaginal tears at birth and later in life more bladder issues. Eat your spuds, but make sure to eat some veggies and lean protein too.