If you had a hard time believing that companies will put anything on their products to convince you to buy it, this video should convince you otherwise. Yes he is referring to American products, but the reality is that our labeling laws in Canada are not that much better.
For instance trans fats, a product we know is terribly unhealthy for us, can be listed as zero grams on many products as long as they are under 0.5g. The reality is that we know even 0.1g is not good for us.
Products can also use health claims on the outside of boxes as long as their product contains at least a small amount of the product it mentions. So while oat fibre may help lower cholesterol, that does not mean the product the claim is on really high in oat fibre. It likely has a little, but may be lower than you think. Now there are a specific set of health claims companies in Canada can use, but many companies have put additional claims on the outside of their products which were not even backed up with science (Ahem, Danone).
So be warned, you are being pitched more than what is really in a food product. Like an old fashioned snake oil salesmen, until we get a better grip on what we allow companies to put on their product labeling, we will have to continue sifting through the confusion.
WARNING: the video below is NOT work safe!