There is not much difference. At 300 pounds you live a normal life and at 400 pounds some things start to limit you.
For me, true extreme obesity starts beyond 450 or 500 pounds.
Walking, getting dressed, getting into a car, bending down, getting up from the floor, getting out of bed, using stairs, etc. The real problems, (health aside), start there.

An exoskeleton for walking when you weigh over 1000 pounds. A lot of fat people would get out of bed with something like that.

I am already too fat to regret my obesity and I have lost the ability to walk. My next goal is to reach and exceed 1000 pounds.

Are they talking about running or walking in the extreme obesity section? With a little luck and a lot of help, I can get out of bed and take two steps before collapsing to catch my breath.
How many people can walk with more than 600 pounds?

Many things we must solve before being bedridden.
I'm not stuck in bed yet, but without my husband's help I can't get up.
It terrifies me knowing that if my house catches fire or has an earthquake, I can't get out of bed and leave my house and no matter how hard my husband tries to help me, it takes a long time.
I'm helpless, we laugh about it with my husband, but it's real. In a fire I depend on the efficiency of the fire brigade or I am going to burn alive. In an earthquake I can only pray and hope that the roof doesn't collapse.
Something simpler a small heart attack and I just have to wait to die, because no one can get me out of the house without a crane.

I am already extremely obese and am taking my last steps before immobility.
I want to have immobility? The truth is that it worries me a bit, but it's inevitable, at some point I'm going to stop walking and I'll have to get used to it.
For the moment I am going to enjoy the food and my obesity.

I want that, I would love to have an extreme body.
I'm happy with my 700+ pounds, but if I could get over 1000 pounds that would be great.
If one day I reach that weight and my heart allows it, I'm going to try to become the fattest woman in history and why not the fattest person alive in history.
It seems easy because I already have extreme obesity, but the reality is that I lack 120 kilos to enter the competition and 350 kilos to break those records.
The fattest people list is full of men, we have to add more women there.

I reached the limit. I am on the verge of immobility.
I am too fat to lose weight with exercise, diets are useless and this is irreversible without surgery.
The next level is getting used to living in bed and that scares me a bit, but I can't walk more than 20 steps anymore and I need my husband's help even to get out of bed.
At this point I don't want to keep gaining weight, but with my husband it's impossible, he always leaves food within my reach.
He has this fetish and he can't control it. He doesn't force me to eat, but he knows I won't be able to resist the urge to taste the food.

It depends on how fat the person is.
Everything is difficult and exhausting for me at 700 pounds, from walking to getting out of bed or out of a chair.
I can't walk much either, I move around walking inside my house. When I go out I use a wheelchair.
Climbing stairs with my weight is crazy, I don't know if I can climb 2 steps but I'm not going to try either.
Another thing I can't do anymore is drive a car, I can't fit in the driver's seat.

I gained a lot of weight when I got over 480 pounds.
My goal was to stop at 600 and today I weigh 700 pounds.
The only thing I can say is that if you want to get fat, you will get fat.
By the time you hit 600 pounds, you'll be too fat to lose weight without surgery. Do little or nothing and eat a lot, that is the life of those of us who are extremely obese.