How does someone lose 30 pounds in 4 days. Other than cutting off a leg I'd say dehydration.
I wonder how many moldy tourists are littering the jungle floors of the world? This guy is a prime case in point for the PSK or a well stocked day pack.
I teach an informal class several times a year centered around the scenario of "When good day hikes turn bad". This is far more common than you think. Here in central Brazil the papers run several of these stories a year. A group of kids goes out on a hike and is found three days later ripped to shreds, dehydrated, covered in ticks, and starving.
It seems like there's no middle ground in terms of preparation here. Either people take to the serra with 60 lb packs or in shorts and a pair of flip flops. I spent 48 hours out with my daughter this week and we managed with about 15 lbs each not counting water. We had a great time in some of the world best scenery. Mac