I started giving dd 1% at about 2.5....I kept her on the full fat a bit longer because she was so thin. Then I realized that her being thin had nothing to do with food...LOL...she ate like a grown up then and still does now! She had a varied diet and didn't require those extra fat calories...so we went to 1%. Most of the fat in whole milk is saturated, and toddlers just don't need that.
With all due respect, toddlers and in fact kids in general DO require a certain amount of sat fats for efficient function of nerves and brains especially. There really isn't any reason, outside of "the lipid hypothesis" (which has had and is still getting holes blown into it by new research daily and has been pretty much disproven), which in turn has led to the "Standard American Diet" and sat fats being demonized. Vegetable oil, on the other hand, has its own issues. (I can provide lotsa links; PM me if interested.) I lost nearly 20 pounds in the last year and I won't tell you how much butter, coconut oil, bacon fat, and full-fat dairy we consume here. LOL Suffice it to say that my (no former) doctor's jaw just about fell into her lap when I disclosed that we eat and cook with coconut oil regularly; she'd just gotten done telling me how spectacular my cholesterol numbers were at my annual physical.
[A quick aside: the vast majority of the research that went into Ancel Keys' work was done with hydrogenated fats, including hydrogenated tropical oils; non-hydrogenated sat fats are in fact proving to be downright essential to healthy nerve growth and brain function, not only in children but adults as well.
http://www.lewrockwell.com/orig10/mercola44.1.html]
So the long and short of it is that you don't need to stop full-fat dairy in the least, not for your LO or even for you. The full-fat stuff is actually more satisfying and keeps you fuller longer, so if you're worried about weight change, you may be consuming FEWER net calories by not being hungry sooner.
