From the text:
“Can this be the same Alex that set out in July, 1990? Malnutrition and the road have taken their toll on his body. Over 25 pounds lost. But his spirit is soaring.”
Chris wanted to depend upon himself, and he was doing that. Malnutrition was simply the price he had to pay..... he was living his dream and doing what he'd set out to do.
Into the Wild