The guy claims he gained about 15kg over a one month period by substituting sugary foods into his diet while keeping his caloric intake the same. That's a massive claim which you'd expect to be backed up by pretty rigorous testing, yeah? Not even close. He doesn't even count his calories.
The whole time I was watching I was waiting to see the numbers. Spoiler alert: there aren't any. Halfway through the 'experiment' he states that he's never counted calories before, proceeds to do it just once, and then claims that his intake appears to be the same as it was before. To embark on a project like this and only measure your caloric intake once throughout the entire thing is incredibly disingenuous behaviour.
If you read reviews about What the Health online, you'll see that lot of it is vegan propaganda. They've manipulated facts (like mentioning relative probability as opposed to absolute) so that they seem more dangerous than it actually is.
Yeah, I second that. I starts out very credible but if you examine what they say, especially regarding sugar and carbs it becomes very clear that it's vegan propaganda and skewing its facts heavily
[1] https://en.wikipedia.org/wiki/That_Sugar_Film
[2] https://en.wikipedia.org/wiki/Fed_Up_(film)