Somewhere I read that bread has most of the essential nutrients for humans, except for vitamin C. That would mean that prisoners who were sentenced to bread and water could last many years if they had fruit occasionally.

I guess the kind of bread, and the reduced caloric needs of prisoners, play a huge role here.

Send that medical aid boat to USA, they need the help more.

Some continuous glucose monitors are MRI-safe, and they keep working after it. Just adding another data point.