Women (depending on height) should eat 1900 - 2500 calories a day. During 1st trimester add 200, during third trimester add 300. I'm 6ft, 175 lbs & I eat 2200 calories a day, so while pregnant I try to eat 2400.. it doesn't happen every day but that's okay so long as I'm eating healthy things, nutrients the baby needs. 75-100g of protein a day, folic acid, calcium, etc. I lost 3 lbs my first trimester & baby is big - growing ahead of schedule.