Certain foods (and smells) will suddenly illicit a very strong and negative response from you. Foods that you previously enjoyed or that didn't bother you now make you want to leave the room because you can't stand the thought of eating it or smelling it.
Common food aversions include coffee, eggs, poultry, beef, milk and dairy product, and green veggies.
Your food aversions should subside or calm down a bit by the second trimester, but food will probably still taste a bit off for the entire pregnancy due to those hormones.
As your hormone levels change, the chemical content of your blood changes, which is often reflected in your saliva. This causes the taste in your mouth to change so foods will taste different than before.
Your sense of smell also becomes more acute and everyday smells can make you nauseous.
You don't have to eat foods that you're averse to, but you do need to eat a balanced nutritious meal that makes up for the nutrients you're lacking.
There is generally no risk to your baby as long as you eat nutritious food that makes up for the missing nutrients.