Actually yes. You can help your body in trying to convince a boy. If you wait to have sex when your body is releasing your eggs you have a higher chance in conceiving a boy. I would wait till I'm ovulating then try, I would put pillows under my lower back and put my feet against the wall helping the sperm reach the eggs. Boy sperm swim faster than girl sperm but boy sperm die off way faster than girls. Sooo it does help with trying for a boy to do these things.
Ignore anything anyone tells you... There is no way by diet, position etc.. That determines the sex of a baby!!