I think it was Einstein who once said, "knowledge is not about what you've learned, it's about what you've managed to unlearn.". The old "calories in, calories out" adage is one of those things you have to unlearn, because as much as it seems to make sense, modern science has shown us that it's simply not true.
Sure, some people disagree, but you'd be farfetched to find anybody in history who proposed a new way of thinking who didn't have people arguing against him.
Furthermore, something being "unproven" (which is what his Wiki says about his propositions) is very different from it being "disproven." Even the most brilliant scientific breakthroughs of our time were, at the time of their inception, unproven.
Whether or not you agree, I still highly recommend watching the whole video. It's rife with good material for discussion.
Your posts are not straightforward.
Here's the wiki quote: "By contrast, such a conclusion has been deemed unwarranted by medical experts and not confirmed by clinical research. For example, in one meta-analysis giving evidence opposite to Lustig's opinion, fructose consumption actually reduced blood glucose levels with no effect on body weight."
It's not "some people" but instead the clear majority of nutrition researchers / specialists. Your argument about "unproven" vs "disproven" is a straw man. Having extensive meta studies that show no support for Lustigs thesis is as close to disprove something as it is possible to do so in nutrition discussions (even though most nutrition studies have major problems in their quality and samplesize quantity).
Further, in your original comment you wrote "modern science has shown us that it's simply not true." and your only support for this was the linking of Lustigs youtube-video (which, to say it nicely, is at least heavily contested). I agree with you that there are many open nutrition questions (and that it is important to keep an open mind for new concepts / ideas), but to postulate that science has shown that "calories in, calories out" is wrong, is untrue.
I think this is definitely the wrong place to have an indepth discussion about the topic, but i just couldn't let your original statement stand by itself without a reply.
http://www.youtube.com/watch?v=0z5X0i92OZQ&feature=youtu...