I've said this before (and I'll repeat it yet again). It's not about bulking food or even calories, but rather the speed of your metabolism instead. At least that's how it was for me when I was consuming between 13,500 to 15,000 calories a day..., and not gaining any weight. Granted what I've just mentioned falls under "extreme" instead of normal. But it affirms the point (for me at least), that one of the best ways to add weight to your frame (or lose it), is to focus on the speed of your metabolism, either by speeding it up or slowing it down. And yes, it takes some serious effort to achieve that outcome.
I'm not saying that calories don't count, but just as someone who wants to lose weight would ask, what do I do to lose fat? My reply would be focus on building or maintaining as much muscles as you can. Look outside the box for answers to your situation, instead of always looking at, or following what every Tom Dick and Jane has been following with less than optimal results.
Do what you would consider sustainable according to your own measuring standards, and not someone else's . This I guarantee you would yield results, and not just short term, but for life.