I have to be picky here. If only 20% of your overall diet this year was keto, then really whatever you were doing the other 80% of the time is 80% (in other words, way more) responsible.
I do strict Keto the first 6 days of the month, which is where I was getting the 20% from.
The rest of the time, I do my normal diet of mostly fast food, too much candy, and no exercise. I might drink a little more water than I used to in this period, but no major changes.
It's a great sub. The keto diet helped me lose about 30 pounds this year, and I was only fully committed to it about 20% of the time.