There is actually no way to decide this, science says it's purely random. Just focus on your health, because morning sickness is going to be tough either way!
Actually my doctor clearly told me that gender is determined purely by chromosomes at the time of fertilization. There is absolutely no medical way or diet to choose the baby's gender.
I know there are many myths about eating certain things, but none of them work and you should avoid random diets. Just focus on a balanced diet to stay healthy.