- There is no obesity epidemic
I'm absolutely not sure about this. I also don't find it very relevant when it comes to my own life. I don't want to be obese, regardless of how many obese people there are. I don't want to carry around all that extra weight, I want to look good and be healthy and energetic. I don't really need to think that there is a huge global crisis just to find out that health, energy and good looks are excellent goals to strive for. Apart from that, I do think it's pretty much a given that we have got a lot heavier during the last half century; I'm just not quite sure if I'd call it an epidemic, though.
In the movie, they also claim that the numbers for the BMI got changed just so more people would be labeled "obese". Yeah, I don't know about that. But I think that the BMI is only a very blunt instrument. It also wasn't even intended as a health indicator by its inventor, and it doesn't take a few factors into account that really, really do matter, such as gender and muscularity.
- McDonald's is not to blame for the obesity epidemic
As the movie puts it, "If you eat 5000 calories per day, you'll get fat no matter what." I couldn't agree more. Spurlock put on a diet that was bound to make him fat and sick, and then blamed it on fast-food. The problem is, he would have got fat and sick just as much if he had eaten high-quality beef steaks and fatty sauces at the cost of $ 50,- per meal. It's not the fast food per se, it's food of high caloric density and fast carbs.
I also agree on the other point: "Nobody forces you to eat at McDonald's". Not a lot to add here, really. If McDonald's is the sole provider of children's playgrounds in some areas, then it's not Mickey D who is to blame but the government that should provide them. Suing a company for selling food everyone knows is unhealthy (at least if you overdo it) is simply ridiculous.
- Spurlock faked his data
I am, in fact, pretty convinced that this one is true. He wanted to make a point which was partly valid, and he wanted to make a convincing and entertaining movie, so he exaggerated some stuff. I'm fairly certain, without having done the maths myself, that Spurlock didn't get 5000 calories per day from 3 McDonald's meals. There's a reason why Spurlock refused to publish his food log. Still doesn't make fast food the best dietary choice, though.
- Fat is not related to heart-disease (i.e., the lipid hypothesis is wrong)
Well, as long as the overwhelming majority of doctors disagree and tell me that the two are, indeed, very much related, I think I'll go with that, thanks a lot.
- Our ancestors ate nothing but meat, so it must be good for us
Yeah, admittedly I exaggerated a bit there myself. The claim is that our hunterer/gatherer ancestors, before we invented agriculture, ate lots of meat (and some fruits and vegs), so our biology is obviously adapted to this and it must be good. There are lots of issues with evolutionary arguments on principle, and in this specific case, there also seems to be a huge pile of missing data. While it is true that longevity declined and bone-structure got worse after the agricultural revolution, this might in part be due to people living together in larger groups, thus spreading diseases, to replacing fruits/vegs with grains, and to several kinds of changes in social structure.
In short, we don't know how much meat they actually ate, the fruits they ate were certainly different from our modern fruits (which are much higher in sugar, for one), and it doesn't follow that "old is always good". After all, we do live longer, work less, and are probably in better health than people a few hundred thousand years ago. (And every single point in that sentence is debatable itself, so there you go...)
To sum it up, I still think that a largely plant-based diet is good for me, that fast-food is pretty bad, and that the so-called "paleo diet" is a fad. But I'm also happy that someone put in the effort to debunk some of the glaring idiocies of "Supersize Me".