Why are you hurting yourself for their expectations? Respect in the workplace is earned through actions, professionalism and good work ethics. Men shouldn't respect you less because you are standing at your natural height........chances are, even in heels, you'll still be shorter than most of them! If a man ever says that to you again, professionally tell him that you would have more respect for him if he was acting like a reasonable person with better morals! You don't owe them anything.