So I have been watching some of that show (600 lb life). The people on there they are much wider than an average person. I don’t understand how their skeletal structure allows for this.
How can their arms go straight down? there is no way the arms are connected to the chest part of the skeleton unless the chest has really expanded?
No, their bones are still attached, just like they are in a thin person. However, their joints, especially in their legs, are going to be all beaten up by that excess weight.
What makes you think their arms will go straight down?
Have you ever seen how a bodybuilder’s arms hang? Their huge lats force their arms to hang away from their body.
They are usually all gimpy looking when they are standing. What kills me is how their feet look. It must be so painful. I suppose that’s why they don’t walk much. I think their bones must get thicker to support the weight, while they are doing the gaining, at first, anyway.
There was one person on a program that aired many years ago who had chronic pain that defied diagnosis, until someone made the connection between the fact that he couldn’t go outside and the possibility of a vitamin D deficiency. He was tested, and turned out to have rickets! Even though he was eating 10,000 or more calories a day, he was STILL malnourished.
He was given megadoses for a while, and this improved his condition. I don’t remember his name, but he had also died in between filming and when the show aired.
Oh, I remember that guy. His family quit feeding him. He would pay neighbor kids out the window to get food for him. They never did get him weighed.
There was a lady who was living in pain, come to find out her hip was broken for a year and no body believed her about being painful. Sad, every case is just so sad. I hate that show.
Many years ago I was on public transport and watched a bloke who had the BIGGEST arms (from bodybuilding) trying to rub his nose which was obviously tickling.
Funniest thing ever. 
One of my cousins was morbidly obese, and could walk only very short distances. Otherwise, she had to get around on a scooter. She died at 57.
I wonder what changes the skeleton goes through with that much weight hanging on it. Could you tell by looking at the skeleton of a 600 lb person that the person had been obese?
If you look carefully at a photo of a morbidly obese person, you will see that their shoulders are of essentially normal width. Their arms do not go “straight down.” Instead they are at an angle corresponding to the contour of the body.
And to clarify, the arms are only attached to the “chest part of the body” indirectly. The upper arm bone (humerus) sockets into the shoulder blade (scapula), which only has a single small connection to the collarbone (clavicle). The collarbone in turn is anchored at its opposite end to the center of the ribcage. While this limits the distance the arms can be from the ribcage, the connection is very flexible.
If you do an image search for “obese skeleton” you’ll get a better idea of what is going on with their bones relative to the rest of their bodies.
The thigh bones will get thicker in response to the stress of carrying around more weight. While the thickness of the thigh bones can indicate that the person was obese, the bones won’t give you anything close to an accurate weight of the person.
There’s the story that when they were shooting “Conan the Barbarian” Ahnold had to lose size on his arms, because his muscles were so big he could not wave the sword around over his head, his arms could not go straight up like that. Body mass does get in the way. An obese person may not hang their arms straight down, but if they lie flat diagonally along the widening torso it won’t look that unnatural.
Carrying excessive weight does cause some increased bone density, but the skeleton becomes less distorted than you’d think. Ever seen someone who’s lost half their body weight? Their skeleton’s still pretty much the same.
I speak from experience. I weight half what I once did.
