I agree on the scientific experiment part. This has no real scientific value, because of the lack of control, prediction results and repeated attempts, to gain a statistical idea of what exactly is going on. However, I didn't see anything in the OP nor the video indicating that anyone thinks eating McDonalds is healthy. The stated point in the video, and the gist of the OP is that it doesn't matter what you eat, as much as diet and lifestyle choices, that determines if most people are obese. Your last paragraph makes an assumption and inference that I don't think was there in the presentation. It's not that eating McDonalds is healthy or unhealthy, its that the blanket statement that its bad might not be not true. Even with all the salt, fat and sugar you get with fast food, by controlling caloric intake and exercising, you can potentially maintain control of your weight. This is obviously an extreme, most people won't eat fast food everyday, but you could if you used some discipline (at least for a month or 3, if there's anything to this). That itself is not scientific, but it indicates that the unscientific assumption that eating fast food will kill you faster than if you didn't eat it is unscientific. More work has to be done to see if there is really anything to what this guy did, because it might be an anomaly or complete nonsense. I'm just happy to see that there is at least an indication that a long held assumption might be wrong. I like it when that happens. It sort of reminds me of the Doctor who invented air conditioning in the mid 1800s. He hypothesized that malaria and other ailments was caused by hot, impure air. In order to treat his malaria patients, he developed the method some machines still use today to cool air off via induction. In order to keep his patients rooms cold, he insulated them, screened off the windows and kept them bed ridden. His cure worked wonders, they recovered, and the malaria stopped spreading so quickly after a few months of starting the treatment. While his treatment worked, it did not work the way he thought it worked. Hot or bad air does not cause or spread malaria, insects do. His treatment worked because the people he was treating were getting cleanish water and food, so they would get better anyway in most cases, and the windows were closed and insulated, stopping insects from getting in and sucking the patients blood. That stopped the transmission of the malaria back into the insect population, which reduced how quickly it would spread during warmer months. So until the real science is done here, we don't really know if his method really did anything specific. You're almost certainly correct that it was just exercise and caloric discipline that helped him become healthier, but the notion that fast food is universally bad is a good assumption to question. I hope people continue to question it, and some real science is done to see if the assumption is valid, invalid, or partially valid. My money is its partially valid, but not as bad as some people claim it is, nor as good as the fast food companies tel us it is. -edit- I know lots of research has been done on this, as I have read a bit about it. I just didn't think the conclusions were very...well conclusive. I have seen studies indicating that fast food is universally bad for you, partially bad for you, and mildly bad for you. I did not think any of them were deep enough to find the real underlying mechanism to justify the results, just more data and potential conclusions on the subject. The book is still open, is my point.