According to Krakauer, a well-nourished person might consume the seeds and survive because the body can use its stores of glucose and amino acids to rid itself of the poison. Since McCandless lived on a diet of rice, lean meat, and wild plants and had less than 10% body fat when he died, Krakauer hypothesized that McCandless was likely unable to fend off the toxins. However, when the Eskimo potatoes from the area around the bus were later tested in a laboratory of the University of Alaska Fairbanks by Dr. Thomas Clausen, toxins were not found. Krakauer later modified his hypothesis, suggesting that mold of the variety "Rhizoctonia leguminicola" may have caused McCandless's death. "Rhizoctonia leguminicola" is known to cause digestion problems in livestock, and may have contributed to McCandless's impending starvation. Krakauer hypothesised that the bag in which Chris kept the potato seeds was damp and the seeds thus became moldy. If McCandless had eaten seeds that contained this mold, he could have become sick, and Krakauer suggests that he thus became unable to get out of bed and so starved. His basis for the mold hypothesis is a photograph that shows seeds in a bag. Following chemical analysis of the seeds, Krakauer now believes that the seeds themselves are poisonous.