I am starting to wonder if we are all watching the same shows
Over all the seasons, I think there were only 2 people who were not living on a daily calorie deficit (ie, dieing slowly but faster than most of us)
The 2 were the ones who killed a moose and a musk ox. And if I am recalling right, one of them even messed that up as some animal stole all the fat, so they couldn't properly use the lean protein. I think he recovered from that by catching some fatty fish though.
Mike Lowe TOLD the producers at the start that he was only going to do 21 days. Before insertion he bailed because there were restrictions on what they could hunt/eat. The producers talked him into staying on and he told them right then that he would only do 21 days.they figured he would make for good ratings and went with it.