Hello
@MLPH and welcome to Talking Point.
Im afraid that end of life with dementia is indeed a roller coaster.
Small amounts of food and fluid are unlikely to make any difference, sometimes people seemingly at end of life rally and start eating and drinking again, so its important to offer food and drink. My MIL was considered to be at EOL and was put on the Liverpool pathway - deemed nil by mouth, but rallied, had to be taken off this pathway and started eating and drinking well again. I was told three times that mum was at end of life, only for her to rally and start eating and drinking again - she eventually died 16 months later.
Im not saying that this will happen to your father - Im just explaining why food is offered.