What's the most amount of weight you've put on in the shortest about of time?

I gained 17kg in half a year.
Then lost them over 4 months.
Then regained the 17kg in 3 weeks.
And a total of 20kg in 4 weeks.

Gaining kilos for the first time is hard, but regaining them after losing them is extremly easy.
1 year

What was the most weight you gained in a week?

16 lbs, but it was a regain after a long diet.
3 years