I think it's a stupid idea.
I can understand the fact that he wants to be able to tell his clients that he knows what they are going through, simply because he gained 70 pounds of fat to only then lose it, but it's not that easy.
Not everyone has the same level of muscle memory as this guy has. Most of his clients are probably fat fucks that have never been in shape anytime throughout their lives. For most bodybuilders, they can go a year without working out and after only getting back into it for 2-3 months they are capable of getting pretty good returns. That won't be the case for the average fat fuck.
Aside from that, I think the effects of this on his body can be disastrous. His body is possibly not used to putting on so much weight by way of consuming terrible foods. He could very well have a heart attack due to this stunt. His logic in that it can't be that bad since most of his clients have lived all their lives overweight doesn't hold much weight either. Those clients have progressively put on fat and have allowed their bodies to adjust over time to the extra load on their hearts, whereas this guy is just shocking his body into a state of obesity. Not too clever if you ask me..
Hey, at least he is original