Believe it or not, I was a scrawny kid. I remember someone, I think it was my mom, commenting that I needed to fill out a bit because my hiking pack was too big, and I couldn't fill the waist band. Oh, how that came true in spades!
My gain was fairly gradual, but I think it really started becoming noticeable late in high school. From there, I get fatter and fatter in pictures, going from probably 190/200 in 2001 to 271 today, with my heaviest at around 285 a few years ago.
To answer your questions, it feels quite different, being fat. My range of motion is a bit more limited, running is not really an option anymore, and there's this belly thing that precedes me everywhere I go. My arms are a little softer, my thighs are definitely fatter, and shopping for clothing in regular clothing stores is essentially impossible unless I'm buying socks.
I've only started consciously gaining recently, and the changes have been subtle. I've noticed a bit more of a craving for fast food, definitely more of an appetite for donuts (especially custard-filled.) I count calories now, though I always look for the highest-calorie option.
The last thing I noticed is that while my waist measurement hasn't changed, I feel like my body composition is changing, like my belly feels fatter. It's weird - above my belly button feels relatively solid and round, but below is soft and squishy, spreads out when I sit down, and has a little arch forming in the middle that wasn't there before.
10 years