I set out to gain weight, was this unsafe?

I wanted to do a bit of a self experiment and I let myself gain weight and set a 6000 calorie a day goal for 1 month. First couple days I just couldn't actually eat enough, I am quite small but then it got easier and I was managing 7000 after the month. I wasn't eating good but I knew I was bigger I had a belly starting already and my jeans were tight (I had to unbutton the most nights).

Well over this month of a rough 6-7000 calorie a day diet I've put on 19ibs in a single month, main thing I can notice is my belly it's really pudgy now.

Was this safe and would I be able to do it again sometime?
I set out to gain weight, was this unsafe?
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