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.
For instance, the evidence against trans fats is seriously overwhelming and convincing. The evidence against carbohydrates? Eh, not so much.
Avoid added sugar, don't worry so much about bread (as long as you avoid the stuff with added sugar, obviously) or rice or paste or potatoes.
https://en.wikipedia.org/wiki/What_the_Health
It's pro-veganism and the narrator is a goofy manchild, but has credible (to me anyway) medical experts.