Content:
- A legit role reversal. Team with a new gainer who's committed to finding the weight you lose. So her gain lags your loss, is controlled by it, etc. It makes recurring content and opens all sorts of teaming options - clothing, exercise, measurements, meals, sexual positions. They change over time and could build momentum with your audience. What's great about this idea, is you could keep your fat fans with a new cash cow. It scales your business.
- Once you hit peak weight, hang out there for another year and give the weight time to settle. Your body will change and make for another look to create content with.
Do things where you're too fat - booths, park equipment, chairs, exercise equipment, etc.
Dark content - with tears, talking about what you can't do, social cost of the weight gain, being unable to stop it, etc.
Similar with health content, but separate video, since some are especially sensitive about health factors.
There's plenty of strong fat chicks. Every lifting gym has them. They tend to be confident. If demand for content was high, I think we'd see more if it. Evaluate market size before putting in all that work. You'll need 2 years of hard training and probably some androgens. There's a good chance the drugs develop secondary masculine characteristics, which could really limit your audience.