It doesn't really matter because I've already stated that eating 7000 kcal is doable. And that (grossly exaggerated) number was based on false assumptions, something to which delluminatus has already agreed.
I think you're the one confused about calories. Even an hour of strenuous lifting burns only ~ 500 kcal. http://www.health.harvard.edu/newsweek/Calories-burned-in-30...
Ferriss claims to have spent only 4 hours in the gym throughout those 28 days, which amounts to approximately 2000 kcal in a month. Meaning he had to somehow find within himself the strength to eat one additional large pizza in a month. Even if he was in the gym for an hour a day, eating 500 extra calories per day is hardly difficult.
4 hours * 500 kcal/hr = 2000 kcal
This would be IN EXCESS of what he would have to eat to maintain homeostasis, which means that he'd need somewhere in the ballpark of 4000 kcal/day JUST TO MAINTAIN HIS WEIGHT. Then he would need an ADDITIONAL amount of calories to allow his body to repair muscles and form new muscle. I'm not even saying it's impossible to gain 34 lbs. of muscle in a month -- just that it would take at least 6000-7000 kcal/day to gain weight that rapidly, not one large pizza/month. Or 3500 kcal/day. It's all nonsense.
Nope, that's not what I said. I even linked to the article that has that exact claim; apparently, you didn't read it.
>just that it would take at least 6000-7000 kcal/day to gain weight that rapidly
I've also said repeatedly that I didn't think this was an obstacle, if it indeed was the amount required. I guess you didn't read that either.
It takes ~2000 kcal/day to maintain an average person's body weight. The only way to build muscle is through strenuous exercise which results in more kcals being burnt during exercise and muscle repair. These two facts alone should tell you that it would be physically impossible (as in, defies the laws of physics) to gain 34 lbs. of muscle in a month eating just 3500 kcal a day.