Pretty much.
We call it "evolution in action".
Also, the people hosting this "survival training" were clearly every bit as stupid as he was. The first clue was not letting them fill their canteens at the creek at the beginning of the trek.
Most of what the survival training guides were teaching sounds completely wrong to me. As someone else said, it was more of a “see how tough you are” endurance course than a real survival course.
“In a Feb. 27 letter to the Forest Service, Bernstein said Buschow may not have trained properly, pointing to comments he made to another camper about drinking a gallon of water a day and eating cheesesteaks to bulk up before the expedition.”
I have read that people eat high fat, high calorie foods when they hike the Appalachian Trail all summer. They still burn fat and calories like crazy and end up losing weight. It sounds like this guy was doing a similar thing, and loading up on calories (energy stores).