I'm not seeing a number of overweight miners as a major issue. It is going to take months to get the shaft down to them. Girth being a go-no go factor in coming out, seeing daylight and family, should provide the motivation to have them meet requirements. With time and motivation, and food supply limited from up top, I don't see weight loss as a big problem.

It also has to be noted that fat is seldom a barrier to getting people into or out of tight spots. Fat moves around quite readily. The limiting factor is almost always bone. In cave rescues it is pretty common to break the color bones of people to allow their shoulders to fold and make moving them through tight spots easier.

One of the problems they face is the psychology and group dynamics of long-term waiting in a tight spot. On the up side they are not alone. On the down side as numbers increase the group dynamics get much more complicated and potentially volatile.

To their benefit they are Chileans, not, in the narrow sense, Americans. Chileans are typically much more psychologically secure within their society and socially prepared to make sacrifices for the larger group. Being secure in their standing they will tend toward compromise instead of resorting to posturing and demanding shows of independence because of their inner insecurity. It helps that violence, while not unknown, is typically not a central point of their identities.

On up side these are experienced miners who are familiar with confined spaces and rough conditions. On the down side these people have been selected to do the work of mining and not necessarily screened for psychological stability over the long-term as submariners usually are.

To the positive the miners have their working society and power structure relatively intact. The people who were leaders and guides are still there so there is no need to work out a new pecking order and power structure. Because of this everyone has a firmly established and secure role. This can be very reassuring and is far superior to situations where strangers are bottled up together and working relationships are disorganized, in flux, and subject to rivalries and jealousies.