It has been remarked in support of that proposition that no fat people came out of Auschwitz (or Singapore, or similar episodes). But is that because they got thin, or did they die before getting thin? Has any research been done on how people of different body types respond to starvation? The full report on this experiment might address that, but the Wiki article doesn't. However, the volunteers for that experiment were "young, healthy men" volunteering as an alternative to military service, so it's unlikely that any of them were obese going in.