Yep. Which is why we can suspect he would have dismissed that diet even if he had known about it.
Roosevelt wouldn't even consent to a physical examination until he was admitted to Bethesda in Mar 44'
He had been in badly declining health since after traveling the 1000's of miles to and from the Tehran Conference in Nov 43.
He was finally admitted with very high blood pressure, fever and rapid pulse.
Before then all he would consent to was a short chat with a Navy doctor that wouldn't even physically examine him.
Amazing these days considering he was pushed around in a wheelchair everywhere he went.
After that, they did all they could to keep Eleanor away from him because all her nagging would give him a meltdown so their daughter Anna became acting First Lady.
Eleanor tried to go to Yalta in 45'. There was no way they were going to be in a confined space for all that time so his daughter Anna went instead.