Chances are your toddler's negativism – saying "no" all the time, running away, throwing things – has probably been surging lately. He's actively testing his limits, putting his newfound mobility and ability to control his environment to use.
It's your job to create and enforce those limits. Your toddler's negativism will affect feeding, sleeping, playing – basically, every area of significant interaction between the two of you.
They're common in toddlers, along with other types of openly negative, provocative behavior. Remember, this is all a normal part of his growing independence, not a plot to drive you crazy!
Learn how to discipline your child in a positive way.