I couldn't find a place to watch the movie, but I found a video on youtube which is an interview with the director of the movie and it raised some very interesting thoughts.
In it, I have learned that the average age that a girl is fully sexually mature is 16....the reason 18 is so often talked about is because we essentially live in a mans world, and the average age of sexual maturity for a man is 18.
Basically that means once a girl reaches the age of 16, her body will generally not change in any significant way aside from weight gain/loss and other things that are controllable, things that have little or nothing to do with puberty.
Beyond that, it said most men in the survey they did, find that without knowing the age of a female in a photo, they found most men find 16 year olds to be the most attractive on average.
To anyone who has looked at the cover of the movie and the poster for it, the girl on both is 14 years old.
Last thing, the average age of models throughout the world is 16, and models are generally dressed and accessorized to look as attractive as possible.
He also brings up a good point that realistically most men are not pedophiles, because the term pedophile refers to someone who is attracted to children (that is, a person who has not reached puberty), whereas someone attracted to a 16 year old does not fall into the definition of pedophile, but legally they use the term rather loosely (pretty much for anyone attracted to a person under the age of consent). So legally, most men are pedophiles, but by definition most men are not.
Definitely raised some interesting points to consider, and by pedophile in the name of the documentary, it refers to anything that falls into the legal usage (such as anyone under the age of consent), not the actual definition. What the title is asking is if all men are attracted to young women who have completed puberty, not whether or not all men are attracted to children.