https://www.timesofisrael.com/freed-hostages-suffered-torture-starvation-and-long-periods-of-isolation-reports/
"In one of the most severe cases of isolation, Channel 12 news reported that the released hostage Avinatan Or was held alone for more than two years and did not encounter any other captives until he was freed on Monday.
According to the report, Or was held in the central Gaza Strip for most of the war under severe conditions, including prolonged starvation. An initial medical examination found that he had lost between 30 percent and 40% of his body weight..."