I think adverts merely react to current thoughts and trends. I deffinately think that they make certain ways of thinking normal and accepted though (like male beauty etc). I'm unsure as to where it all started though, maybe it's a massive cycle...media (magazines pointing out "horrible" things on celebs)- advertising - media etc etc etc
I do think the ads are a catalyst in the paranoia spiral most people seem to be in..."oh you have celulite, you want to get rid of that! Here-look at our new wonder product". Then maybe only exacerbating peoples poor self image.
This is why I applaud Dove's "PRO-age" ads...taking a cleaver view on things, making it possitive. While all of the other campaigns are anti-age, anti-flab and anti-everything else people seem to have...this seemed to encorage natural, obtainable beauty. Brilliant branding in my oppinion.
I'm pretty sure, if you are insecure...you are going to be like that-if you're not insecure-adverts wouldn't make you like that.
I hope this all makes sense???? (i find it really hard to write out my opinion haha)